Seminars and Colloquia at ESO Santiago
December 2018
Abstract
In the last few years, several large photometric and spectroscopic survey have targeted
the Galactic bulge. As a result, there is now robust observational evidence that it hosts
(at least) two components, with different metallicity, shape, kinematics and alpha element
ratio. They might be the result of two different formation channels, or the same one,
with parameters evolving over time.
I will review the latest observational results and proposed models. I will finally emphasize
the main questions that remain open and how we plan to address them in the next few years.
Abstract
Arp 187 is one of the fading active galactic nuclei (AGN), whose AGN
activity is currently decreasing in luminosity, and is a good
laboratory to obtain the crucial information on the accretion disk
physics and the lifetime of AGN. We investigate the observational
signatures of AGN in Arp 187, which trace various physical scales from
less than 0.1 pc to the nearly 10 kpc, to estimate the longterm
luminosity change over 10^4 years. The VLA 5 GHz, 8 GHz, and the ALMA
133 GHz images reveal bimodal jet lobes with ~5 kpc size and the
absence of the central radio-core. The 6dF optical spectrum shows that
Arp 187 hosts narrow line region with the estimated size of ~1 kpc,
and the line strengths give the AGN luminosity of Lbol = 1.5x10^{46}
erg/s. On the other hand, the current AGN activity estimated from the
AGN torus emission gives the upper bound of Lbol < 2.2x10^{43} erg/s.
The absence of the radio-core gives the more strict upper bound of the
current AGN luminosity of Lbol < 8x10^{40} erg/s, suggesting that the
central engine is already quenched. These multi-wavelength signatures
indicate that Arp 187 hosts a ``dying'' AGN: the central engine is
already dead, but the large scale AGN indicators are still observable
as the remnant of the past AGN activity. The central engine has
experienced the drastic luminosity decline by a factor of ~10^{3-5}
fainter within ~10^4 years, which is roughly consistent with the
viscous timescale of the inner part of the accretion disk within ~500
years. We also propose that those dying AGN could be found using the
AGN indicators with a different physical scale such as 12 um band
luminosity tracing AGN torus (R~10 pc) and the optical [O III]5007
emission line tracing narrow-line regions (R=10^{2-4} pc).
Abstract
The history of the primordial Universe is recorded in the all-pervading intergalactic medium (IGM), which is believed to contain most of the ordinary baryonic material resulting out of the Big Bang.
Throughout the epoch of structure formation, the IGM became clumpy and acquired peculiar motions under the influence of gravity and acted as a reservoir for the gas that gets accreted, cools and forms stars within galaxies and as a sink for the metal-enriched material, energy and radiation which they eject.
Along the line of sight to a distant source - a quasar, a gamma-ray burst, a galaxy - every parcel of IGM gas selectively absorbs certain wavelengths of light due to the presence of the various chemical elements in it.
Through the analysis of these absorption lines we can study the spatial distributions, motions, chemical enrichment, and ionization histories of gaseous structures from redshift seven and beyond until the present.
It is an exciting game: from few details of little apparent significance, it is possible to deduce a surprising number of important conclusions about our Universe, especially when we link the information provided by absorption lines with the complementary information derived from the evolutionary properties of luminous galactic structures.
In particular, thanks to QSO absorption lines, it is possible to address issues like:
What were the physical conditions of the primordial universe?
What fraction of the matter was in a diffuse medium and what fraction and how early condensed in clouds?
Where are most of the baryons at the various redshifts?
When and how did the formation of galaxies and large scale structure start?
How early and in what amount have metals been produced?
When and how, after the Dark Ages following recombination, did the Universe get reionized?
What was the typical radiation field, how homogeneous, what was producing it?
Which constraints on cosmological parameters and types of dark matter (e.g. neutrinos) are derived from the large scale structure traced by the IGM?
Does the standard big bang model make the correct predictions about
the primordial element abundances and the temperature evolution of the Cosmic Microwave Background (CMB)?
Do fundamental constants of Physics vary with cosmic time?
Does General Relativity correctly describe our Universe?
These fundamental questions have driven in the years the design and construction of ever more performing telescopes and instruments, from the ESO 3.6m to the ELT and beyond.
Abstract
I will present the relation between black hole mass and the dynamical mass of massive
galaxies at high z (z~4-6). We have considered a sample of ∼15 quasars at high
redshift for which we have obtained measurements of the host galaxy kinematics from
ALMA observations of molecular or atomic transitions. For the first time, we are able to
measure galaxy masses dynamically, by modelling the kinematics of galaxy disks, thus
avoiding all the problems and biases from photometric measurements of stellar masses.
Up to redshift z∼5, the MBH/Mgal ratio is consistent with the extrapolation of the relation
inferred at z < 3. At z > 5 we find a steady decrease of the MBH/Mgal ratio with increasing
redshift, possibly witnessing the phase of fast growth of the BHs compared to the host
galaxies. I will discuss how these results fit within the coevolution scenario and highlight
the constraints that they pose on models of galaxy evolution.
Abstract
The history of the primordial Universe is recorded in the all-pervading intergalactic medium (IGM), which is believed to contain most of the ordinary baryonic material resulting out of the Big Bang.
Throughout the epoch of structure formation, the IGM became clumpy and acquired peculiar motions under the influence of gravity and acted as a reservoir for the gas that gets accreted, cools and forms stars within galaxies and as a sink for the metal-enriched material, energy and radiation which they eject.
Along the line of sight to a distant source - a quasar, a gamma-ray burst, a galaxy - every parcel of IGM gas selectively absorbs certain wavelengths of light due to the presence of the various chemical elements in it.
Through the analysis of these absorption lines we can study the spatial distributions, motions, chemical enrichment, and ionization histories of gaseous structures from redshift seven and beyond until the present.
It is an exciting game: from few details of little apparent significance, it is possible to deduce a surprising number of important conclusions about our Universe, especially when we link the information provided by absorption lines with the complementary information derived from the evolutionary properties of luminous galactic structures.
In particular, thanks to QSO absorption lines, it is possible to address issues like:
What were the physical conditions of the primordial universe?
What fraction of the matter was in a diffuse medium and what fraction and how early condensed in clouds?
Where are most of the baryons at the various redshifts?
When and how did the formation of galaxies and large scale structure start?
How early and in what amount have metals been produced?
When and how, after the Dark Ages following recombination, did the Universe get reionized?
What was the typical radiation field, how homogeneous, what was producing it?
Which constraints on cosmological parameters and types of dark matter (e.g. neutrinos) are derived from the large scale structure traced by the IGM?
Does the standard big bang model make the correct predictions about
the primordial element abundances and the temperature evolution of the Cosmic Microwave Background (CMB)?
Do fundamental constants of Physics vary with cosmic time?
Does General Relativity correctly describe our Universe?
These fundamental questions have driven in the years the design and construction of ever more performing telescopes and instruments, from the ESO 3.6m to the ELT and beyond.
Abstract
The history of the primordial Universe is recorded in the all-pervading intergalactic medium (IGM), which is believed to contain most of the ordinary baryonic material resulting out of the Big Bang.
Throughout the epoch of structure formation, the IGM became clumpy and acquired peculiar motions under the influence of gravity and acted as a reservoir for the gas that gets accreted, cools and forms stars within galaxies and as a sink for the metal-enriched material, energy and radiation which they eject.
Along the line of sight to a distant source - a quasar, a gamma-ray burst, a galaxy - every parcel of IGM gas selectively absorbs certain wavelengths of light due to the presence of the various chemical elements in it.
Through the analysis of these absorption lines we can study the spatial distributions, motions, chemical enrichment, and ionization histories of gaseous structures from redshift seven and beyond until the present.
It is an exciting game: from few details of little apparent significance, it is possible to deduce a surprising number of important conclusions about our Universe, especially when we link the information provided by absorption lines with the complementary information derived from the evolutionary properties of luminous galactic structures.
In particular, thanks to QSO absorption lines, it is possible to address issues like:
What were the physical conditions of the primordial universe?
What fraction of the matter was in a diffuse medium and what fraction and how early condensed in clouds?
Where are most of the baryons at the various redshifts?
When and how did the formation of galaxies and large scale structure start?
How early and in what amount have metals been produced?
When and how, after the Dark Ages following recombination, did the Universe get reionized?
What was the typical radiation field, how homogeneous, what was producing it?
Which constraints on cosmological parameters and types of dark matter (e.g. neutrinos) are derived from the large scale structure traced by the IGM?
Does the standard big bang model make the correct predictions about
the primordial element abundances and the temperature evolution of the Cosmic Microwave Background (CMB)?
Do fundamental constants of Physics vary with cosmic time?
Does General Relativity correctly describe our Universe?
These fundamental questions have driven in the years the design and construction of ever more performing telescopes and instruments, from the ESO 3.6m to the ELT and beyond.
Abstract
Abstract
Abstract
The history of the primordial Universe is recorded in the all-pervading intergalactic medium (IGM), which is believed to contain most of the ordinary baryonic material resulting out of the Big Bang.
Throughout the epoch of structure formation, the IGM became clumpy and acquired peculiar motions under the influence of gravity and acted as a reservoir for the gas that gets accreted, cools and forms stars within galaxies and as a sink for the metal-enriched material, energy and radiation which they eject.
Along the line of sight to a distant source - a quasar, a gamma-ray burst, a galaxy - every parcel of IGM gas selectively absorbs certain wavelengths of light due to the presence of the various chemical elements in it.
Through the analysis of these absorption lines we can study the spatial distributions, motions, chemical enrichment, and ionization histories of gaseous structures from redshift seven and beyond until the present.
It is an exciting game: from few details of little apparent significance, it is possible to deduce a surprising number of important conclusions about our Universe, especially when we link the information provided by absorption lines with the complementary information derived from the evolutionary properties of luminous galactic structures.
In particular, thanks to QSO absorption lines, it is possible to address issues like:
What were the physical conditions of the primordial universe?
What fraction of the matter was in a diffuse medium and what fraction and how early condensed in clouds?
Where are most of the baryons at the various redshifts?
When and how did the formation of galaxies and large scale structure start?
How early and in what amount have metals been produced?
When and how, after the Dark Ages following recombination, did the Universe get reionized?
What was the typical radiation field, how homogeneous, what was producing it?
Which constraints on cosmological parameters and types of dark matter (e.g. neutrinos) are derived from the large scale structure traced by the IGM?
Does the standard big bang model make the correct predictions about
the primordial element abundances and the temperature evolution of the Cosmic Microwave Background (CMB)?
Do fundamental constants of Physics vary with cosmic time?
Does General Relativity correctly describe our Universe?
These fundamental questions have driven in the years the design and construction of ever more performing telescopes and instruments, from the ESO 3.6m to the ELT and beyond.
Abstract
It has been shown that, at near-IR wavelengths, Type II supernovae (SNe II) have the potential to become standardizable candles as good as SNe Ia. This promising result, however, is limited by the small SN sample used in the studies, which makes the result not fully statistically robust. In this talk I will present the results of a follow-up campaign we carried out during 2015-2018 to obtain optical and near-IR photometry along with optical spectroscopy of SNe II. We use these new data to compute SN II distances through the Photospheric Magnitude Method (PMM), and to construct SN II near-IR Hubble diagrams. The latter allow to constrain more robustly the PMM distance precision at near-IR bands.
Abstract
We present an analysis of archived molecular line observations of the high-mass molecular clump IRAS 16562−3959 taken at 3 mm using the Atacama Large Millimeter/submillimeter Array at 1.7 arcsec angular resolution (0.014 pc spatial resolution). This clump hosts the actively accreting high-mass young stellar object (HMYSO) G345.4938+01.4677, which is associated with a hypercompact H II region and a HMYSO-jet. We identify and analyze emission lines from 22 molecular species (encompassing 34 isomers) and classify them into two groups at the clump scale, depending on their spatial distribution. One of these groups gathers shock tracers (e.g., SiO, SO, HNCO) and species formed in dust grains like methanol (CH3OH), ethenone or ketene (H2CCO), and acetaldehyde (CH3CHO). The second group collects species closely resembling the dust continuum emission morphology and are formed mainly in the gas phase, like hydrocarbons (CCH, c-C3H2, CH3CCH), cyanopolyynes (HC3N and HC5N), and cyanides (HCN and CH3C3N). Emission from complex organic molecules (COMs) like CH3OH, propanenitrile (CH3CH2CN), and methoxymethane (CH3OCH3) arise from gas in the vicinity of a hot molecular core (T~100 K) associated with associated HMYSOs. Other COMs such as propyne (CH3CCH), acrylonitrile (CH2CHCN), and acetaldehyde seem to better trace warm (T~80 K) dense gas. Deuterated ammonia (NH2D), on the other hand, is detected mostly in the outskirts of IRAS 16562−3959 and associated with near-infrared dark globules, probably gaseous remnants of the clump’s prestellar phase. The spatial distribution of molecules in IRAS 16562−3959 supports the view that in protostellar clumps, chemical tracers associated with different evolutionary stages—starless to hot cores/H II regions—exist coevally.
Abstract
Abstract
November 2018
Abstract
The Soul Of Lupus with ALMA (SOLA) is a project focused on understanding the formation of substellar objects in the Lupus clouds. I will briefly describe the project, and then explain more in detail the case of a low-mass star included in the SOLA sample: Par-Lup3-4. This object was extensively studied in the past since it was one of the few very low-mass stars with a jet imaged in the optical. I will show new ALMA observations that have allowed us to
study the dust and gas content of the target and its surroundings. I will also discuss the potential detection of a deeply embedded substelar object candidate in the vicinity of Par-Lup3-4.
Abstract
We show ALMA observations to 'normal' H-alpha star-forming galaxies at z=1.46 and 2.23 selected from the High-z Emission Line Survey (HiZELS). The galaxies have previously got AO-assisted H-alpha observations with SINFONI at ~0.2" (~1kpc) resolution revealing thick rotating disks presenting massive clumps of star-formation. Using ALMA Band-3 we observe large and massive reservoirs of cold molecular gas with masses which are usually ~2-3 times larger than that seen in stars, more extended, and show smooth radial profiles without significant clumpy structures (as those seen by SINFONI). One galaxy is resolved in CO(2-1) at 0.2" resolution revealing that both phases of the ISM, ionised an molecular, have similar rotation velocity and velocity dispersion at ~100km/s levels. We observe a flat rotation curve up to 2x its half light radius, so assuming a thick rotating disk we can put constraints on its dynamical mass (~1.5*10^11Mo) and dark-matter fraction (f_DM~0.6). Even though HiZELS galaxies cover a wide parameter space in terms of gas content, their integrated properties still follow the Schmidt-Kennicutt law, similarly to `normal' galaxies seen in the local Universe. Using ALMA Band-7 we derive the H-alpha dust-corrected star-formation rates, finding that these galaxies fall in the so-called `long-lasting' mode of star-formation which could continue up to the present day at that fixed SFR.
Abstract
The Large and Small Magellanic Clouds are a pair of nearby, likely rather
massive dwarf galaxies. Located at 50 and 60 kpc from us, at the moment
well within the halo of the Milky Way, the LMC and the SMC are believed to
be the satellites of our Galaxy. However, the epoch of their accretion,
their binary lifetime and their masses are largely unconstrained. This
uncertainty poses a serious challenge to our attempts to reconstruct the
properties of the Milky Way from the observables delivered by the ESA’s
Gaia satellite. Using the wide and deep DECam images, we have mapped out
the Magellanic periphery and detected BHB stars possibly residing in the
LMC’s halo. I will present the results of a spectroscopic follow-up
campaign of our candidate Magellanic halo stars carried out with the FORS2
(VLT). Implications of the extension of the LMC stellar halo as well as
the past interaction of the Large Cloud with the Small will be discussed.
Abstract
Creating and maintaining Web pages at www.eso.org can easily be achieved using ESO's installation of AEM (Adobe Experience Manager, formerly called CQ5). I will give a general introduction into how AEM WCMS (Web Content Management System) is used at ESO, show some special use cases and will also explain in which cases AEM should not be used. You will have ample time for questions.
Abstract
The identification of the carriers of diffuse interstellar bands (DIBs) is a long-standing problem in astrophysics. Despite nearly 100 years of study and more than 500 known DIBs, there is clear evidence linking only a few DIB interstellar features with one molecule, C60+. In this talk I will give a brief review of DIBs and describe the ongoing ESO Large Programme (EDIBLES) that hopes to determine their nature (Cox et al.). I'll also illustrate how DIBs can be used as probes of astrophysical conditions. Finally work will be presented at high spectral resolution using the CRIRES instrument in order to investigate DIB properties in the infrared.
Abstract
The Carina Nebula is a giant and rich star-forming region located in the southern Galactic plane. It hosts more than 60 massive O and B stars including η Carina and several hundred protostars, making it one of the most spectacular regions of high-mass star formation in the Galaxy. Moreover, due to its relatively nearby distance (2.3 kpc) and given that our line of sight toward Carina is not obscured by intervening Galactic extinction, this region is an excellent region to study star formation, feedback processes and triggered star formation.
Using the Mopra telescope, we have targeted 61 regions of bright and compact 870 μm dust continuum in the Carina Nebula region to study their molecular line emission at 3mm. In this talk I will present the properties of molecular line emission of the clumps detected in Carina, and compare their properties to those of star forming clumps located at a similar distance to us in the Galactic Plane. I will also address the unusual lack of maser emission in this region, and relate this to the difference in the physical properties of the clumps in Carina compared to other regions in our Galaxy.
Overall our results are consistent with the scenario in which the high radiation field of η Carina is dramatically affecting its local environment, and therefore the chemical composition of the dense clumps.
Abstract
The LIGO-Virgo collaboration is organised in several groups proceeding at different kind of data analysis. At the University of Florida and at LIGO Livingston, I worked on the detector characterisation for noise reduction and Quasi Normal Mode signals extraction. I will present these two techniques which give an idea of the scenery behind the detections.
Abstract
Observations reveal the cosmos to be astonishingly simple, and yet deeply puzzling, on the largest accessible scales. Why is it so nearly symmetrical? Why is there a cosmological constant (or dark energy) and what fixes its value? How did everything we see emerge from a singular “point” in the past? Many lines of evidence point to a quantum beginning of spacetime. Hitherto, proposals for such a beginning were connected to cosmic inflation. However, new mathematical techniques for describing quantum effects in gravity have revealed flaws in these proposals. More positively, they provide a glimpse of a more minimal and predictive quantum cosmology. Exciting consequences include the simplest-yet explanation of the dark matter - as comprising stable, right handed partners of the known left handed neutrinos - and a simpler, non-inflationary explanation of the origin of the large scale structure of the universe.
Abstract
Supernova (SN) 2018oh (ASASSN-18bt) is the first spectroscopically-confirmed type Ia supernova (SN Ia) observed in the Kepler field. The Kepler data revealed an excess emission in its early light curve, allowing to place interesting constraints on its progenitor system (Dimitriadis et al. 2018; Shappee et al. 2018b). Here, we present extensive optical, ultraviolet, and near-infrared photometry, as well as dense sampling of optical spectra, for this object. SN 2018oh is relatively normal in its photometric evolution, with a rise time of 18.3±0.3 days and dm15 (B) = 0.96±0.03 mag, but it seems to have bluer B - V colors. We construct the “uvoir” bolometric light curve having peak luminosity as 1.49×10^43 erg s^-1 , from which we derive a nickel mass as 0.55±0.04 Msun by fitting radiation diffusion models powered by centrally located 56Ni. Note that the moment when nickel-powered luminosity starts to emerge is +3.85 days after the first light in the Kepler data, suggesting other origins of the early-time emission, e.g., mixing of 56Ni to outer layers of the ejecta or interaction between the ejecta and nearby circumstellar material or a non-degenerate companion star. The spectral evolution of SN 2018oh is similar to that of a normal SN Ia, but is characterized by prominent and persistent carbon absorption features. The C II features can be detected from the early phases to about 3 weeks after the maximum light, representing the latest detection of carbon ever recorded in a SN Ia. This indicates that a considerable amount of unburned carbon exists in the ejecta of SN 2018oh and may mix into deeper layers.
Abstract
Type II Supernovae (SNe) II are produced by the final explosions of massive stars (>8 M ), which retain a significant part of their hydrogen envelopes before the explosion. These SNe show a large diversity in their transient behaviour, which is likely determined by differences, not just in explosion properties, but also in progenitor star characteristics. I will present an analysis of a new sample of SNe II occurring within low-luminosity galaxies, comparing these with a sample
of events in brighter hosts. This analysis is performed comparing SN II spectral and photometric parameters and estimating the influence of metallicity (inferred from host luminosity differences) on SN II transient properties. Finally, I will present some examples of peculiar SNe II exploding in low luminosity galaxies and the implications of their behaviour in the determination of the explosion and progenitor parameters.
Abstract
The Dark Energy Survey is in the final year of a six-year survey using the DECam imager on the 4m Blanco telescope to measure cosmological parameters through observations of type Ia supernovae, large scale structure, galaxy clusters, and weak lensing. From the full survey, we expect to assemble a sample of 2,000 photometrically classified type Ia supernovae. In this talk, I’ll present measurements of cosmological parameters from a sample of 207 spectroscopically classified supernovae from the first three years of the survey that, when combined with the CMB and low redshift supernova, are as constraining as any measurement on cosmological parameters to date.
Abstract
about 1pc in radius and at a distance of about 0.5kpc it is
the closest star forming region with O stars.
Until now this cluster has been understood to have formed as one burst with
about 2/3rds of the gas being expelled due to the photoionisation and winds
from the massive stars. The recent discovery by Beccari et al. (2017)
that the colour-magnitude diagramme of the ONC contains three well
defined populations appears to shatter this model. The only currently
viable explanation is that the three sequences are stars with an age
difference of about 1Myr. The implication is that the ONC formed in
three bursts, with star formation still on-going in the last burst. I
will present a model which may explain these observations by an interplay
between stellar feedback and cluster dynamics and provide an Gaia DR2
point of view of the ONC.
Abstract
The OVRO 40 meter telescope has been monitoring the 15 GHz flux density of about 1800 blazars twice per week since 2008. The main findings enabled by this program include constraints on the relative location of the radio and gamma-ray emission site in blazars, characterization of the variability of these sources, and more recently the discovery of symmetric achromatic variability thought to be produced by gravitational lensing of the jet of an active galaxy. Our current efforts are directed towards commissioning a polarization receiver, improve the variability characterization of the full sample and use the light curves to predict source properties in other bands.
Abstract
Cepheids are important distance indicators in the local Universe and key objects for testing the predictions of stellar evolution and stellar pulsation theories. A presence of Cepheids in eclipsing binary systems give us an opportunity to measure and study their physical parameters, including the mass. The analysis of such systems is very challenging and new methods had to be developed to take full advantage of this configuration. In total, we have studied eight Cepheids in seven eclipsing binary systems and found firm relations between such observed parameters as period mass and radius. The results based on evolution and pulsation models can be now compared with observations and challenged. The study resulted in finding evidence for binary interactions during the evolution and a non-pulsating object inside the instability strip. Our measurements provide strong constraints for solving the famous Cepheid mass discrepancy problem. We have also measured the first dynamical mass and determined the evolutionary status of a type II Cepheid.
Abstract
Machine learning is now commonplace in both science and industry and is an extremely powerful way to model data. I will introduce the types and basic concepts of common machine learning models and outline a few use-cases. I will briefly go through (start to finish) an example of a project in industry using machine learning techniques, including feature engineering and model evaluation.
Abstract
Abstract
Abstract
We recently established that Mars lost an ocean’s worth of water, while the Curiosity rover has recently detected organics on the Martian surface and in the atmosphere. If Mars had a rich chemical and diverse past, how much of these biomarkers were lost to space, and how much are currently stored in the sub-surface? Are sub-surface habitable niches connecting now with the atmosphere?
The answers to these fundamental questions of Mars evolution and habitability lie in robotic investigations of the planet’s surface and atmosphere. In the last decade, we have obtained the most comprehensive search for organic material in the Martian atmosphere, permitting us to test for regions of active release and their evolution over time.
We are preparing for the human exploration of Mars, and these recent insights about Mars’ past habitability are greatly assisting us in identifying the most promising research sites. In this talk, I will present our latest discoveries and I will discuss the future steps taken by several space agencies in the exploration of the red planet.
Abstract
In the work that I present in this talk we use integral-field spectroscopic data from the Multi-Unit Spectroscopic Explorer (MUSE) to investigate how star formation within bars is connected to structural properties of the bar and the host galaxy. The absence of star formation in the bar region that has been reported for some but not all galaxies can theoretically be explained by shear. However, it is not clear how star-forming bars fit into this picture and how the dynamical state of the bar is related to other properties of the host galaxy. We use spatially resolved Hα flux from MUSE observations from the Close AGN Reference Survey (CARS) to estimate star formation rates in the bars of 16 nearby (0.01 < z < 0.06) disc galaxies. We further use the instrument’s imaging capabilities to perform a detailed multi-component photometric decomposition. In this talk, I will present the results obtained from comparing the star formation in the bar with structural properties. Furthermore, I will show the detailed 2D distribution of star formation in the bar and the results from testing an AGN feeding scenario.
Abstract
Debris disks contain the solid remnants of planet formation that are in collisional cascade, and are proof that solid accretion has produced solids at least km-sized. It is thus not surprising that debris disks are sometimes accompanied by planets, which reveal themselves through their gravitational imprint on debris disks (sharp edges, apsidal alignment, warps…). For planets that are currently beyond reach of detection of our instruments and facilities, that is, planets in mature systems and/or at large distance from their host star, studying their impact on debris disks is actually our only chance to characterize them. Yet, in the quest for other inhabited worlds, unraveling distant planetary components is of prime importance. Indeed, it is only through interactions between distant planets and debris disks that icy bodies are allowed to permeate the Habitable Zone, reach terrestrial-like planets residing there, and deliver with water and organics to them.
I will focus here on planets on eccentric orbits, show how their interactions with debris disks theoretically facilitates the transport of icy bodies within the habitable zone of planetary systems, and present as well new ALMA observations of two debris disks around which planets on eccentric orbits have been previously inferred.
Abstract
Abstract
AM CVn-type systems are ultracompact binaries with orbital periods of 5-65 minutes, where each binary consists of a white dwarf accreting material from a degenerate or semi-degenerate companion. They are strong foreground sources of gravitational waves in the LISA frequency range, and are evolutionarily linked to double white dwarf binaries and cataclysmic variables. I will overview some recent developments in the field, including results from Gaia and our discovery of a 15.7-minute orbital period AM CVn in a K2 field, before focusing on the question of how these binaries form. I will present data on the first known fully-eclipsing AM CVn, Gaia14aae. Stellar parameters measured from eclipse photometry of the system can provide strong constraints on the system's prior evolution. I will show that these properties do not agree with predictions based on any of the proposed formation channel, and are strongly inconsistent with a double-white dwarf progenitor system due to the elevated donor mass. I will then show that this elevated donor mass appears to be true across the AM CVn population.
October 2018
Abstract
Abstract
We present a photometric study of the dwarf galaxy population in the core region (≤ rvir /2) of the Fornax galaxy cluster based on deep u’g′i′ photometry from the Next Generation Fornax Cluster Survey. All imaging data were obtained with the Dark Energy Camera mounted on the 4-meter Blanco telescope at the Cerro-Tololo Interamerican Observatory. We identify 642 dwarf galaxy candidates within rvir /2 and 258 dwarf galaxies within rvir /4. Dwarf luminosities range between −17<Mg′<−8 mag, corresponding to typical stellar masses of 9.5 ≳ log M⋆/M⊙ ≳ 5.5, reaching ∼3 mag deeper in point-source luminosity and ∼4 mag deeper in surface-brightness sensitivity compared to the classic Fornax Cluster Catalog (FCC). Morphological analysis shows that surface-brightness profiles are well represented by single-component Sérsic models with average Sérsic indices of ⟨n⟩u′,g′,i′ = (0.78−0.83) ± 0.02, and average effective radii of ⟨reff⟩u′,g′,i′ = (0.67−0.70) ± 0.02 kpc. Color-magnitude relations indicate a flattening of the galaxy red sequence at faint galaxy luminosities, similar to the one recently discovered in the Virgo cluster. A comparison with population synthesis models and the galaxy mass-metallicity relation reveals that the average faint dwarf galaxy is likely older than ∼5 Gyr. We study galaxy scaling relations between stellar mass, effective radius, and stellar mass surface density over a stellar mass range covering six orders of magnitude. We find that over the sampled stellar mass range several distinct mechanisms of galaxy mass assembly can be identified: i) dwarf galaxies assemble mass inside the half-mass radius up to log M⋆∼8.0, ii) isometric mass assembly in the range 8.0<log M⋆/M⊙<10.5, and iii) massive galaxies assemble stellar mass predominantly in their halos at log M⋆ ∼10.5 and above.
Abstract
Interstellar dust is a key component of galactic ecosystem, as well as a redistributor of light. Great uncertainties still remain, however, about properties of dust, especially in environments substantially different from those in the Galactic disk and in the Magellanic Clouds. I will talk about several ongoing research projects and ideas of probing dust emission and/or attenuation in such extreme environments as the Galactic center and in high-z extreme starburst galaxies.
Abstract
Abstract
It is readily accepted that many galaxies are inhabited by dense, compact objects deep in their centres, manifesting as supermassive black holes and/or nuclear star clusters (NSCs). Their widespread presence and apparent similar scaling relations with properties of their hosts implies that these black holes and NSCs are two related flavours of central massive object that play essential roles in their hosts’ evolution. How do these NSCs form? How do they relate to black holes and their host galaxies? Does environment regulate their formation mechanisms? Addressing these questions requires sensitive observations of lower-mass galaxies where NSCs dominate. The unprecedented depth and coverage of the Next Generation Virgo Cluster Survey (NGVS) — expanding our sample of Virgo Cluster members to new low-mass regimes — enables a thorough exploration of the photometric properties of NSCs throughout Virgo, ranging from the dense cluster core to more diffuse groups still falling into the cluster potential. In this talk, I will describe ongoing efforts to constrain the effects of local environment on the formation and growth of NSCs. I will introduce a novel density-based hierarchical clustering algorithm used to identify various substructures and environments throughout Virgo using the coordinates of 3,687 Virgo members in the NGVS. I will then present a comparison of the properties of NSCs, their hosts, and non-nucleated counterparts in the different cluster substructures and discuss the implications of these results for NSC formation and evolution.
Abstract
I will present the Herschel discovery of high-density cloud filaments, which are forming clusters of OB-type stars. Given their high star formation activity, these so-called mini-starburst clouds/ridges could be seen as “miniature and instant models” of starburst galaxies. The characteristics of mini-starburst ridges investigated with the NOEMA and ALMA interferometer challenge star formation models and shed light on the origin of massive clusters. In one of these ridges, the measured star formation rates (SFR) contradicts statistical models of star formation rates. Moreover, its measured core mass distribution suggests that the stellar initial mass function (IMF) may not be determined, in these extreme environments, at the prestellar stage. These results motivated the setting up the ALMA-IMF Large Program, project, which was accepted for Cycle 5 and whose source sample and main objectives will be presented.
Abstract
Eta Car is one of the most massive, and intriguing, Luminous Blue Variables known. In its core resides a binary with a 5.54 years orbital period. Visible, infrared, and X-ray observations suggest that the primary star exhibits a very dense wind with a terminal velocity of about 400 km/s, while the secondary shows a much faster and less dense wind with a terminal velocity of 3000 km/s. The wind-wind collision zone at the core of Eta Car is thus a complex region that deserves a detailed study to understand the effect of the binary interaction in the evolution of the system. In this talk we will perform a review of the basic principles of the optical/near-infrared interferometry, together with our unique imaging campaign with VLTI - GRAVITY of the Eta Car's core. The superb quality of our interferometric data, together with state-of-the-art image reconstruction techniques, allowed us to obtain, with milliarcsecond resolution, continuum and chromatic images across the BrG and HeI lines in the Eta Car K-band spectrum (R~4000). These new data together with models of the primary wind of Eta Car has letting us to characterize the spatial distribution of the dust and gas in the inner 40 AU wind-wind collision zone of the target.
Abstract
Abstract
The CHaracterising ExOPlanet Satellite (CHEOPS) is a mission jointly led by Switzerland and ESA which was selected in October 2012 as the first small-class mission in the ESA Science Programme. CHEOPS will be the first space observatory dedicated to search for transits of exoplanets by means of ultrahigh precision photometry on bright stars already known to host planets. This talk will present the mission and its expected science return.
Abstract
The role of the turbulence in the ISM is fundamental and the statistical tools have been the most accurate way to performed turbulence studies in the last decades. In this talk I will present the results of statistical analysis to characterized turbulent motion of ionized and molecular gas. These analysis include different statistical tools: Power Spectrum, Structure correlation function, and Velocity Channel Analysis (VCA). They were performed using a simulated HII region, Orion observational data, and observational 13CO emission from the SEDIGISM survey. The main conclusion is that the VCA tool is less sensitive to projections and better to apply in observational data to characterized turbulence motion. I will also present very preliminary results using the Principal Component Analysis (PCA) technique on molecular gas in W43 region. The results are in: Medina et al. 2014; Arthur, Medina & Henney 2016; Schuller et al. 2017, Medina et al. in progress.
Abstract
A major challenge for detecting low mass planets around M stars is the stellar activity. Dark spots on the surface of the star can give rise to RV variations and hence mimic the presence of a planet. Therefore, extracting weak signals in active stars is difficult, especially when the planetary orbital period is close to the stellar rotation period. K2-18 is an early M dwarf that is moderately active. I will present a combined analysis of contemporaneous photometry, multi-wavelength RV observations, and activity indicators for this system and show how such analysis can be a powerful tool to distinguish between planetary and activity signals.
Abstract
Diffuse Interstellar Bands (DIBs) are non-stellar weak absorption
features of unknown origin found in the spectra of different
astronomical objects when they are viewed through one or several
clouds of Interstellar Medium. Galaxies other than ours offer the
opportunity of study the behavior of DIBs under physical (e.g.
radiation field) and chemical (e.g. metallicity and relative
abundances) different to those typically found in the Milky Way. This
can in turn, put further constrains on the nature of the agents
creating these features. Because of their weakness, studies targeting
extragalactic DIBs are relatively scarce. This is a research that
will certainly blossom at the E-ELT era. However, we can already start
paving the way.
In this talk, we will illustrate how MUSE can help us in this quest. I
will use as examples some results on two highly reddened systems. In
the first one, AM 1353-272, we established a gradient of DIB strength
in a galaxy at more than 150 Mpc (Monreal-Ibero et al. 2015, A&A, 576,
3). In the second one, The Antennae Galaxy, we measured the strength
of the l5780 and l5797 DIBs in more than 100 independent line of
sights, thus mapping these DIBs in a system outside the Local Group
for the first time (Monreal-Ibero et al. 2017, A&A, 615, 33). The
distribution of DIB strength was compared with that of atomic
hydrogen, molecular gas, and PAHs as traced by the emission in the
mid-infrared. In both cases, DIB strength correlates well with
extinction, similar to results for the Milky Way.
September 2018
Abstract
Abstract
We report that one of WZ Sge-type stars, which orbital period is very
close to the period minimum, displays excellent evidence for extremely
low mass-transfer rate, much lower than that in all studied
cataclysmic variables (CVs). This conclusion follows from a very low
contribution of the accretion disc to the total emission, a low white
dwarf (WD) temperature, and a very low X-ray luminosity. The optical
spectrum of this object during its only known superoutburst in 2006 is
similar to other WZ Sge-type stars, showing Balmer and He I absorption
lines. However, in quiescence, it looks very much like a pure WD; the
spectrum shows no sign of any emission lines which are usually
observed in CVs, with the only exception for a weak emission core in
the Halpha absorption trough. We found that the WD has a temperature
of Teff=10600±500 K and it contributes all 100% of the light at
wavelengths shorter than ~5500 A. At longer wavelengths, there is a
small excess of emission (at most 20% of the WD light at the NIR
wavelengths) which is consistent with a brown dwarf donor with
Teff≅1600K, suggesting the post-period minimum nature of the object.
The discovered almost complete termination of mass-transfer in a CV is
not consistent with prior theory and observations, according to which
the mass-transfer rate is decreasing, approaching the period minimum
during CV evolution, but never vanishes. An important implication of
this finding is that if the mass-transfer terminates, for any reason,
in the majority of CVs bypassing the period minimum, then their
appearance should be almost non-distinguishable from DA white dwarfs
with a temperature of 10-11 kK. This indicates that the missing
population of CVs at the period minimum should be searched among such
WDs.
Abstract
Variability is arguably the defining feature of Active Galactic Nuclei (AGN), and is observed in every waveband, so variability studies are fundamental to understanding the extreme physical conditions of accretion disks near supermassive black holes. In the last decades, most of the AGN variability analyses have used small samples with relatively good light curve sampling or large samples with poor sampling, assuming that sources with similar physical properties have a similar variability behavior. However, in order to test this assumption, we need a large sample of AGN with well sampled light curves. In this talk I will present the current status of our QUEST-La Silla AGN variability survey. We used the QUEST camera on the ESO-Schmidt telescope to obtain well sampled optical light curves of AGN in well-studied extragalactic fields that already have multiwavelength observations. I will present our results on the study of the link between variability properties (e.g., characteristic time-scales and amplitudes of variation) and physical parameters of the system (e.g., black-hole mass, luminosity, and Eddington ratio). In addition, I will present our results on variability-based AGN selection.
Abstract
In the past few years, observations of dust polarization with ALMA revealed unprecedented high resolution observations of the magnetic field surrounding young stellar objects. It shed light upon the key role of the magnetic field within the tiniest scales of star formation. We present our work on the imaging of high angular resolution ALMA dust polarization observations of the three Class 0 protostellar sources Serpens SMM1, Emb 8, and Emb 8(N), from the Serpens Main star-forming region. With spatial resolutions up to 40 au at 870 $\mu$m, we expose unpredicted very high polarization fractions along the outflow cavities in Serpens Emb 8(N) and SMM1, allowing us to investigate the physical processes involved in the radiative alignment of dust grains by UV radiation along the outflow cavity walls. Accompanying these continuum and polarization maps are 1mm molecular tracers, which we use to investigate outflow and their correlation with the polarized emission. The thermal emission from the central protostar SMM1a, appear to be confusing as many physical processes seem to happen around this central source. This lead us to some investigations concerning the flux evolution of SMM1. In the context of recent flux variability study of this source, we tried to perform an analysis of a possible flux evolution on a one-year time scale. We support this work with a spectral index investigation to evaluate the optical thickness of the sources in SMM1. Due to flux calibration issues, this will require to claim any real variability. Finally, we present a work done for the ALMA commissioning team, concerning the polarization mosaicking capabilities of ALMA. We use ALMA mosaic polarization data of the Orion Kleinmann-Low Nebula, and compare the polarization data results within different mosaic sampling patterns to investigate the impact of these sampling patterns on the quality of the polarization data.
Abstract
The number of debris discs discovered in high-contrast imaging is still scarce. Despite recent discoveries with both space- and ground-based telescopes, the number of debris discs with known surface brightness distribution of their scattered light amounts to only 30. However, far-infrared studies have shown that this stage of planetary system evolution is very common, with at least 20% to 30% of the main-sequence stars having such a belt of colliding planetesimals, as revealed by the infrared excess of their spectral energy distribution. I will present the outcome of a dedicated search for these belts in scattered light, with the high-contrast imager SPHERE at the VLT. Called SHARDDS (SPHERE High-Angular Resolution Debris Discs Survey), this search aims at understanding why those discs are so difficult to reveal in scattered light, by targeting stars with large infrared excess but no detection to date. We test the hypothesis that those discs are compact therefore difficult to angularly resolve and disentangle from the glare of their bright host star with ground- or space based imagers. We will review the detections of this survey and the non-detection to constrain the albedo of the dust in those discs.
Abstract
Water maser emitting planetary nebulae (PNe) are believed to represent the very early PN stages of intermediate-mass stars. Among the five/six water maser emitting PNe, IRAS18961-2505 is peculiar: it is the only one that is observed at optical wavelengths, including its central star, while the others are strongly obscured.
Optical images, and high- and low-resolution long-slit spectra of IRAS18061-3505 will be presented, which allows us to reconstruct the mass ejection processes involved in its formation, as well as to obtain the chemical abundances, and to estimate the characteristics of the progenitor star. The results confirm the extreme youth of the nebula, suggest a 4 Msun progenitor star, and point out to a peculiar evolution of the central star.
Abstract
Massive star formation is a key astrophysical process. Despite representing only ∼1% of the Galactic stellar population, massive stars (M⋆ > 8 M⊙) input more energy and momentum into the interstellar medium than the other 99% combined. In other words, massive stars govern the energy budget of galaxies and regulate their evolution across the Universe. However, many unknowns still remain, especially regarding the earliest stages of their formation. In this short presentation, I will present three cornerstones in the process of high-mass star formation: i) how to form the hyper-dense, hyper-massive molecular clouds in which massive stars preferentially form ii) how these molecular clouds form high mass stars (dynamical versus quasi-static evolution) and iii) how to circumvent the radiation pressure issue at small scale.
Abstract
The infrared bubbles are a powerful tool to study the interaction of young stars with their enviroment, since they modify the interstellar medium by heating the dust, ionizing the gas and generating an expanding bubble. The morphologies of the dust bubbles reveal important information about the structure and physical properties of the medium in which they are expanded.
In this contribution is analyzed the molecular gas associated with the IR bubble complex S108-S111 (Churchwell et al., 2006). S108, S109, S110 and S111 that form a 'tripolar bubble'. In addition, a large number of Infrared Dark Clouds (IRDCs) were identified in the region, which are characterized as sites of recent star formation within the molecular clouds.The study was carried out analyzing data of the molecules 12CO, 13CO and C18O observed with the APEX telescope, and from high density tracers data taken from the MALT90 survey.
The molecular counterpart of the bubbles has been detected and numerous IR sources, classified as young stellar objects, have been found associated with the region. Dense clumps observed in high density tracer molecules such as HCO+(1-0), HNC(1-0) and N2H+(1-0) were identified. The study is complemented by the analysis of Herschel images in the far IR. It has been detected that the high density tracers coincide with the emission of dust in the far IR and numerous IR sources classified as class I have been found associated with this emission.
Abstract
During my presentation, I will first give a broad overview of the state of art in activity diagnostics and corrections. Then, I will present the objectives and preliminary results of a dense observing campaign of 4 active stars, combining high-precision space photometry (K2), multi-band ground photometry (TRAPPIST-N), spectroscopy (HARPS, SOPHIE and CARMENES) and spectropolarimetry (ESPaDOnS and NARVAL). In the long run, the objective is to conclude on the best observing strategy and correction methods to mitigate stellar activity, allowing for the detection of planets with weaker signals, down to Earth analogs.
August 2018
Abstract
As the largest gravitationally bound systems in the Universe, galaxy clusters are a unique laboratory for studying the extremes of galaxy evolution. Large-scale cluster potential has been known to play a significant role in the morphological and colour transformation of galaxies. I use chemical abundance to tracer the cumulative effect of various baryonic processes affecting galaxy evolution in a galaxy cluster. Using observations with DEIMOS/Keck, I find a cluster-scale gradient in the metallicity of star-forming galaxies and present it as a new angle to identify physical processes driving the chemical enrichment of cluster galaxies. In this talk, I will present my work with IllustrisTNG simulations, where we find a systematic signature of ``chemical pre-processing'' of infalling galaxies. I will show that the inflow of enriched gas (pre-enrichment) plays a significant role in driving the chemical evolution in the overdense environment in illustrisTNG simulations.
Abstract
We have carried out deep and very high angular resolution polarimetric ALMA observations toward the massive protostar driving the HH 80-81 radio jet. The observations clearly resolve the disk oriented perpendicular to the radio jet, with a radius of 290 au. The continuum brightness temperature, the intensity profile, and the polarization properties clearly indicate that the disk is optically thick inside a radius of 170 au. The linear polarization of the dust emission is detected almost all along the disk and its properties suggest that dust polarization is produced mainly by self-scattering. However, the polarization pattern presents a clear differentiation between the inner (optically thick) part of the disk and the outer (optically thin) region of the disk, with a sharp transition that occurs at about 170 au. The polarization characteristics of the inner disk suggest that dust settling has not occurred yet with a maximum dust grain size between 50 and 500 µm. The outer part of the disk has a clear azimuthal pattern but with a significantly higher polarization fraction compared to the inner disk. Although this pattern is consistent with self-scattering of a radiation field that is beamed radially outward, as expected in the optically thin outer region, a contribution from non-spherical grains aligned with respect to the radiative flux cannot be excluded.
Abstract
Scientific data, simulations and observations in the sciences often have high impact visuals that never cease to provide us with interesting insight into our Universe. Often, a deeper understanding of scientific observations is found by how we present the results, concepts and ideas to all audiences, both scientific and non. Nowadays, thanks to modern computing, Virtual Reality (VR) represents a tool to take data exploration to the next level. I will explain how VR has been used for immersive visualisation, the related challenges, the tools developed during my internship and how to use these tools without any previous knowledge of VR. At the end of the talk, everyone will be able to load her/his work in VR.
Abstract
Supernovae and other types of transients occurring in the nuclei of galaxies are challenging to find and study, but they offer an opportunity to peek into the surroundings of the supermassive black holes. We will present our systematic search for nuclear transients in the OGLE and Gaia Surveys, both in the archival and real-time data and discuss ways of rapid and machine-learning assisted early classification of transients. We investigated about 20 unusual transients out of hundreds detected. Among discovered objects, there were supernovae and candidates for tidal disruption events (OGLE16aaa, Gaia16aax). We also found examples of unusually long and luminous flares, which could either be supernovae interacting with the interstellar medium or new types of flaring phenomena related to the supermassive black hole.
Abstract
Abstract
It has been just over 26 years since its inception that the concept of Eigenvector 1 in the context of the quasar main sequence was studied which still remains very attractive since it stresses correlations between various parameters and implies the underlying simplicity. Usually, the Eddington ratio was considered to be the main physical driver behind this sequence. In Panda et al. 2017, 2018, we test the hypothesis that the “actual driver is the peak of the broad band quasar spectrum, connected with the maximum temperature in the quasar accretion disk”. We perform the computations of the Fe II and Hbeta line production using the photoionisation code CLOUDY for a constant density single cloud model, and we locate the theoretical points on the optical plane. Our theoretically computed points cover well the optical plane part populated with the observed quasars, particularly if we allow for super-solar abundance of heavy elements. Explanation of the exceptionally strong Fe II emitter requires a stronger contribution from the dark sides of the clouds. However, we conclude that there is “no single simple driver behind the sequence”, as neither Eddington ratio nor broad band spectrum shape plays the dominant role.
Abstract
I will talk about the telescope, the repair and maintenance work done on orbit, and the scientific results, which have been and still are quite amazing.
Abstract
This talk will be about the activities that we are developing at Centro Interdisciplinario de Estudios Atmosféricos y Astroestadistica (CEAAS) for astronomy. We will focus the talk specially in site testing, PWV, optical turbulence and astronomical seeing over a observatory. Finally we will show an example of ASTROMET web tool in operational mode.
Abstract
Galaxies form and evolve via physical processes that operate over a large dynamic range of spatial scales, from the tens of kpc scales of galactic disks down to the sub-pc scales in which stars form within GMCs. Optical integral-field spectroscopy, especially when combined with IR, sub-mm, and radio datasets, offers a powerful tool to study the physics of star formation, feedback injection, chemical enrichment, and galactic dynamics within galaxies, but comprehensive surveys of nearby galaxies have been limited by their ~500 pc -1 kpc spatial resolution. At such coarse resolution individual sites of star formation, metal production and feedback injection cannot be resolved. In this talk I will present early results from the "Physics at High Angular Resolution in Nearby Galaxies" (PHANGS) survey, a combination of two ESO and ALMA Large Programs aimed at mapping the ionized and molecular ISM and stellar content of all massive star forming galaxies in the Local Volume (D<17 Mpc) at <100 pc resolution. I will also discuss the Local Volume Mapper (LVM) project, one of the programs to be executed as part of the Sloan Digital Sky Survey V (SDSS-V). The LVM will start operating in 2020, and will produce optical IFU data-cubes of the bulk of the Milky Way disk, the Magellanic Clouds, M31, and M33, and dozens of Local Group dwarfs, with spatial resolutions ranging from 0.1 pc to 20 pc, resolving the scales in which stars form and feedback and metals are injected into the ISM.
July 2018
Abstract
The SAMI Galaxy Survey is an integral field spectroscopy survey using the fibre-fed SAMI instrument at the Anglo-Australian Telescope. It delivers 3500-7000 A spectroscopy for 3000 z<0.1 galaxies. Unlike other large IFU surveys, SAMI explores a range of environments, and has sufficient spectral resolution (30 km/s) to probe the kinematics of low-mass galaxies. Here we describe the data included in the upcoming public Data Release 2, and present a number of science highlights obtained by the SAMI Team, with particular attention to one of the ESO follow-up programs: studying the kinematics of dwarf galaxies.
Abstract
Building on the success of previous time-domain surveys with the Palomar 48-inch Telescope, the upgraded Zwicky Transient Facility (ZTF) recently began Science Operations. With an improved 47-square-degree field-of-view, ZTF's volumetric survey speed is an order of magnitude greater than its predecessor PTF. The entire Northern Sky is surveyed every 3 days to a depth of 20.5 magnitude, as part of a public survey. After image processing, transients are automatically identified and packaged as "alerts". A live "stream" of these alerts is released to the community, with several hundred thousand alerts in a typical night. The AMPEL broker has been operating since June, and is already providing filtering services to the ZTF collaboration. In this talk, the ZTF science case will be outlined, and the AMPEL broker will be introduced. In light of the latest IceCube results identifying a correlation between neutrinos and a flaring blazar, our realtime IceCube-ZTF correlation analysis with AMPEL will be highlighted.
Abstract
The classes of Type IIb, Ib, and Ic core-collapse supernovae appear to represent progressively greater stripping of the progenitor star's outer envelope prior to explosion, but it is unclear how much of this stripping is due to stellar winds and mass-loss, or to interaction with a massive binary companion. We have used the Hubble Space Telescope to search for surviving binary companions to nearby stripped-envelope supernovae in the ultraviolet. I will describe our results for the broad-lined Type Ic SN 2002ap, and for the Type IIb SN 2001ig
Abstract
background quasars and gamma-ray bursts (GRB) offer a unique way to
study the conditions of star forming regions in high redshift galaxies.
package PyMC, to fit absorption lines with Voigt profiles in order measure the column
densities of 10 different elements as well as neutral and molecular hydrogen.
The measured relative abundances are further used to fit depletion sequences
and determine the gas to dust ratio and the host intrinsic visual extinction.
Abstract
The vast number of known extrasolar planets implies that planet formation is a natural outcome of the star formation process. With the advent of sensitive radio-wave observations and together with developments in theory, rapid progress is being made in understanding how the reservoir of material in circumstellar disks is transformed into planetary systems. In particular, the process of disk evolution and planet formation will leave an imprint on the distribution of solid particles at different locations in a protoplanetary disk, resulting in a variety of substructure (gaps, rings, spirals, vortices, clumps, etc.) over large and small scales. The role of these small-scale features is fundamental: theory predicts that without substructure large solids would be lost due to radial drift, impeding planetesimal and planet formation. Recent ALMA observations of protoplanetary disks at high spatial resolution show some form of substructure, but to understand the prevalence and diversity of these features we need to go beyond small number statistics with heterogeneous resolution and sensitivity. In this talk, I will discuss the first results from our ALMA Large Program "Small-scale substructure in protoplanetary disks", aimed at characterizing the underlying substructure of 20 nearby classical disks. These observations constrain the spatial distribution of solid particles of roughly 1 mm in size, from dust continuum images in Band 6 (1.3 mm) with exceptional spatial resolution (down to a radius of ~3 AU). I will introduce the details of the survey, present its current status, and discuss preliminary findings.
Abstract
Abstract
The determination of accurate stellar parameters of giant stars is essential for our understanding of such stars in general and as exoplanet host stars in particular. Precise stellar masses are vital for determining the lower mass limit of potential substellar companions with the radial velocity method. Our goal is to determine stellar parameters, including mass, radius, age, surface gravity, effective temperature and luminosity, for the sample of giants observed by the Lick planet search. Furthermore, we want to derive the probability of these stars being on the horizontal branch (HB) or red giant branch (RGB), respectively. We compare spectroscopic, photometric and astrometric observables to grids of stellar evolutionary models using Bayesian inference. We provide tables of stellar parameters, probabilities for the current post-main sequence evolutionary stage, and probability density functions for 372 giants from the Lick planet search. We find that 81% of the stars in our sample are more probably on the HB. In particular, this is the case for 15 of the 16 planet host stars in the sample. We tested the reliability of our methodology by comparing our stellar parameters to literature values and find very good agreement. Furthermore, we created a small test sample of 26 giants with available asteroseismic masses and evolutionary stages and compared these to our estimates. The mean difference of the stellar masses for the 24 stars with the same evolutionary stages by both methods is only ⟨ΔM⟩=0.01±0.20M⊙. We do not find any evidence for large systematic differences between our results and estimates of stellar parameters based on other methods. In particular we find no significant systematic offset between stellar masses provided by asteroseismology to our Bayesian estimates based on evolutionary models.
Abstract
The Carina Nebula Complex (CNC) is a spectacular star-forming region located at a distance of 2.3 kpc (Smith & Brooks 2008), which is close enough to observe a wide range of size scales in detail. With more than 65 O-stars and more than 900 young stellar objects identified (Smith et al. 2010), it is also the nearest analogue of more extreme star forming regions, such as 30 Doradus in the Large Magellanic Cloud. I will present the latest results of a major effort to study the relationship between the neutral, ionized and molecular gas phases of the ISM in the Carina region using the Australia Telescope Compact Array (ATCA), the Mopra telescope and ALMA. The Mopra CO images, combined with far-infrared data from Herschel, have allowed us to determine the overall molecular mass and its distribution across the CNC (Rebolledo et al. 2016). Detection of HI self-absorption features has revealed the presence of cold neutral gas, signalling the phase transition between atomic and molecular gas (Rebolledo et al. 2017). I will also present high-quality images of the radio continuum at 2.0 GHz obtained with ATCA, which can then be compared with the structures seen in atomic and molecular gas maps. Finally, I will present the latest results of a ALMA campaign to study the the effect of massive star feedback on the location, mass, and kinematics of the small-scale fragments within massive star- forming clumps in two distinctive regions of the CNC using important diagnostic lines of the abundant molecular species such as HCN, and HCO+.
Abstract
In massive galaxy clusters the interactions between galaxies and cluster gas as the galaxies enter the cluster for the first time may lead to quenching of the star formation. This interaction transforms them into passively evolving bulge-dominated galaxies. With the Gemini/HST Galaxy Cluster Project we aim to map the evolution of these bulge-dominated cluster galaxies from z~2 to the present.
Here we present evidence for a z=0.405 cluster. The Abell 851 cluster is unique in this project. It contains a different distribution of bulge-dominated versus disk-dominated galaxies than the other already studied clusters. We link its bulge-dominated galaxy population to our larger sample of bulge-dominated galaxies in rich clusters spanning from the present to redshift superior to 1.
Based on absorption line strengths measured from our high signal-to-noise spectra, we find that our data support primarily passive evolution of the galaxies, even in such a unique cluster.
Abstract
The WISE mission has discovered a rare population of high-redshift, hyper-luminous infrared galaxies, all with bolometric luminosities above log L_Bol/L_Sun > 13 , and many with log L_Bol/L_Sun > 14. Selected by their extremely red mid-IR colors and shown to have very hot dust temperatures, these hot, dust-obscured galaxies, or Hot DOGs for short, are dominated by the emission of a highly obscured, actively accreting supermassive black hole and may probe a key stage in galaxy evolution. I will present the latest results of our ongoing research to understand the nature of these enigmatic objects with emphasis in results from our latest NIR spectroscopic campaigns, as well as on recent results from ALMA observations on W2246-0526, the most luminous Hot DOG, that show this system is likely experiencing a multiple merger as well as significant AGN feedback.
Abstract
Abstract
Chile could be duly called an "island country". Looking at its location on a map and observing its contrasting borders: a desert, the Andes -one of the world’s highest mountain chains-, the Pacific Ocean and the Sea of Drake, on the extreme of South America keep it away from everything. Moreover, within its more than 4000 km length, you can appreciate how its administrative regions and their geographic and human landscapes, also seem to correspond to many different islands.
In this unique country, the Atacama Desert is a predominant region. Its climate, geomorphology, geology, economy, history, and many other features, differentiates it in a very special way. And what makes it more attractive is the fact of being a little known region and less kind region for occasional travelers and its dwellers whether Chilean or foreign.
From the scientific point of view the Atacama Desert is a natural laboratory for sciences such as Archeology, Anthropology, Astronomy, Astrobiology, Geology and, in addition, the repository of the History of Chile and many other topics.
=================
Chile es lo que podría llamarse un "país - isla!. Basta mirar su ubicación en un mapa y al reconocer sus límites se observa como sus límites: un desierto, los Andes -una de las más altas cadenas montañosas del mundo-, el Océano Pacífico y el Mar de Drake, extremo de Sudamérica lo distancian de todo. Más aun, en su más de 4000 km de largo, cuando se observan sus regiones administrativas y sus correspondientes paisajes tanto geográficos como humanos, vemos también muchas islas diferentes.
En ese país singular el Desierto de Atacama es una región relevante. Su clima, su geomorfología, su geologia, economía, historia y muchos otros rasgos lo diferencian de manera muy especial. Más atractivo lo hace el hecho de ser una región poco conocida y menos amable tanto para el viajero ocasional o para el residente, chileno o extranjero.
Desde el punto de vista científico es un laboratorio natural para ciencias como la Arqueología, Antropología, Astronomía, Astrobiología, Geología y, además un interesante repositorio de la Historia de Chile y muchos otros temas.
Abstract
Since the construction of modern facilities such as VLTI and CHARA, interferometry has become a key technique to probe massive stars and their often-complex circumstellar environments. In this seminar, I will briefly introduced the basics of this technique and its application to astrophysics. We will then start our journey around massive stars at the highest-possible angular resolution. I will show how interferometry can address various questions about massive stars through the characterisation of the geometry and kinematics of their stellar surface or environment. We'll talk about stellar formation, binarity, mass-loss, and even stellar rotation. Finally, we'll see how the latest generation of instruments which combine the power of interferometry and spectroscopy offers amazing spectro-imaging capabilities.
Abstract
In this talk, I will describe the new Arena for performing room-scale Virtual Reality (VR) experiments at ESO, recently set up in the Vitacura Library. I will present the data visualization research project that motivated the purchase of this system via SSDF funds, and explore a range of other different applications for this new facility, including outreach events, scientific analysis, as well as VLT operations. The talk will be immediately followed by a tour of the VR Arena, after which (and for the rest of the day) everyone will be invited to experience the immersiveness of room-scale VR for themselves.
June 2018
Abstract
I will present results on cosmic evolution of galaxy pairs based on
studies of two large samples: a local sample (KPAIR, 170 pairs), and a
mid-z sample (0.2 < z < 1) selected in the COSMOS field (CPAIR,
more than 300 pairs). We found that, since z=1, the pair fraction evolves
as (1+z)^(2.2+-0.2). Major mergers involving star-forming galaxies
(i.e., wet and mixed mergers) have significant impact on the stellar
mass assembly of massive galaxies, and are sufficiently abundant to
account for the formation of massive ellipticals. Results from our FIR
observations using Spitzer and Herschel revealed a puzzling difference
between star-forming galaxies in mixed pairs (S+E) and in wet pairs
(S+S) in the sense that, relative to single spiral galaxies, spirals
paired with ellipticals show no SFR enhancement while spirals
paired with spirals show strong enhancement. Furthermore, the SFR
enhancement in S+S pairs decreases (with increasing redshift)
substantially between z=0 and z=1. I will discuss some plausible
interpretations for these results in the context of the still
elusive theory of merger-induced starbursts.
Abstract
I will report the first light curves of millimeter line emission toward the archetypal carbon star IRC +10216 that was monitored with a 10-m ground based mm single dish telescope. I shall also show some preliminary results from our on-going ALMA/7-m ACA monitoring of the same star for more than two years. Millimeter line variation in AGB stars was observationally confirmed only recently. It is driven by the pulsating central star. Part of the varying line spectral features can be justified to be masers by their light curve parameters. The varying mm lines have the potential to be used as cute probes to the dynamical stellar wind launching processes in AGB stars. The ALMA results have revealed puzzling line-profile variation patterns, while explanations to them are still lacking.
Abstract
We have now measured over 100 black hole masses with various techniques, and the important role that black holes play in galaxy evolution is becoming more clear. After a review of such techniques and the results they lead to, I’ll discuss the significant issues concerning the demographics, as we do not have as good of control of both systematics for the measurements and good representation for the range of galaxy type. I will overview the current state of the data and models, with particular attention to the important understanding that NGC1275 provides.
Abstract
The low wind effect is a phenomenon disturbing the phase in the pupil of a telescope in the absence of wind. It is well explained by the radiative cooling of the telescope spiders, creating air temperature inhomogeneities across the spiders. Because it is unseen thus uncorrected by traditional adaptive optics (AO) systems, it significantly degrades the quality of AO-corrected images. I will provide a statistical analysis of the strength of this effect as seen by VLT/SPHERE after 3 years of operations. I will analyze its dependence upon the wind and temperature conditions inside the dome. I will describe the mitigation strategy implemented in 2017: a specific coating with low thermal emissivity in the mid-infrared was applied to the spiders of UT3 at the VLT. I will quantify the improvement in terms of image quality, contrast and wave front error using both focal plane images and measured phase maps. This study made us of the data lab presented on Wednesday by Eduardo Pe~na.
Abstract
Abstract
How supermassive black holes form and what causes the tight relation with their host galaxies is unclear, however, merger-driven accretion might play an important role. Dual AGNs are fantastic windows on these processes. Unfortunately, only a small number of these systems have been confirmed as such, and even less have been thouroughly characterised. In this talk I will present a study of a candidate dual AGN discovered serendipitously while searching for recoiling black holes. Although the "dual" nature of the system is still a matter of debate, evidence that accreting black holes reside in the nuclei of both galaxies is tantalising.
May 2018
Abstract
A clear picture is emerging in which supermassive black hole growth episodes (luminous AGN) are directly linked to major galaxy mergers. In this scenario, the more traditional unification paradigm in which orientation is the main parameter only holds at lower luminosities, while for the more violent accretion events, triggered by major mergers, we find evidence for an evolutionary sequence in which the AGN is first heavily obscured (Compton-thick), to then reveal an unobscured quasar. In this talk, I will present observational evidence in support of this scenario. In particular, I will discuss the main results from our NuSTAR AO-1 program aimed to obtain high energy observations for a sample of 12 nearby galaxies undergoing major mergers. Then, I will present the first results from our program aimed to obtain optical and near-IR Integral Field Unit (IFU) spectroscopy and ALMA maps for a sample of confirmed nearby dual AGN (separation <10 kpc). In addition to providing general properties of this population, I will focus on two remarkable systems, NGC6240 and Mrk 463. Both systems show evidence of large kpc-scale tidal features, complex gas dynamics and kinematical evidence for both inflows and outflows. These results clearly show the importance of performing high resolution multi wavelength studies covering kpc scales in order to understand the complex connection between black hole growth and galaxy evolution in this critical phase.
Abstract
Through the use of GRAAL + HAWK-I instrument, high precision photometry of the dwarf planet-moon binary system, Eris and Dysnomia, was acquired over three nights.
Concluding my short internship period at ESO, I will present my methodology in the reduction of HAWK- I data of Eris. I will then discuss the subsequent analysis of its photometric variability, and further explore the implications of the initial data produced to potentially characterize the surface heterogeneity of Eris, and perhaps elucidate the mystery of its exact rotational period.
Abstract
The Lyman alpha radiation emitted from high-redshift sources is an excellent tool to study the properties of the galaxies themselves and of the medium they live in. We make use of the first 2 seasons of the VIMOS data taken within the VANDELS survey to assess if Lyman alpha emission depends on environment. We first define the over and under dense regions in the VANDELS fields, providing an adaptive estimate of the 3D density field and running simulations on the chapman cluster at ESO Vitacura. Then, we look at the photometric, spectroscopic, and photometric properties of the VANDELS Lyman alpha emitters. We find that Lyman alpha emitters avoid the most dense regions of the field at 3<z<4. Also, the galaxies located around dense regions are characterized by low Lyman alpha equivalent width and have Lyman alpha profiles consistent with the presence of a low HI column density in the interstellar and circum-galactic medium. This can be related to the way galaxies consume their gas and evolve in dense environments
Abstract
Studying the stellar mass—size relation of galaxies at non-local redshifts is a challenging but important task to understand galaxy formation and evolution. For a thorough analysis, two main galaxy parameters need to be measured securely on large samples at all redshifts: distance/redshift and size. In this talk, I will introduce the work that I have done with the GRIZLI software, which will be used to improve the redshift measurements for galaxies in the Hubble Frontier Fields (HFF) and my following effort in quantifying the mass—size relation of those galaxies. Equipped with the deepest multi-wavelength Hubble Space Telescope images in existence, reliable galaxy sizes can be measured, which will allow me to probe new regimes of the stellar mass—size relation of both disk-dominated and spheroidal galaxies, previously unavailable for analysis. Furthermore, by modeling galaxies as a composition of bulges and disks, their different stellar populations can be distinguished. This means that an investigation of the mass and size growth as a function of redshift not only of galaxies, but individual galaxy components can be pursued.
Abstract
TBD
Abstract
Edge-on spiral galaxies offer a privileged view of the balance between gravity and turbulence, including the effects of star formation, supernovae, and shocks. They also offer the opportunity to measure the height of star-forming gas, a dimension that is usually hidden in typical star formation studies. However, the height is important, as it converts a gas surface density into a gas volume density. And this gas volume density is a fundamental quantity in many star formation models because it is related to the gravitational free-fall time. In the talk, I will present CO(2-1) data from the Submillimeter Array that spatially resolve the vertical distribution of molecular gas in two high-mass, edge-on galaxies. I will compare our direct measurements of the height of the molecular gas to predictions from radiative transfer models. Finally, I will discuss the star formation efficiency in a sample of moderately-inclined galaxies where we have some constraints on the height of the star-forming gas.
Abstract
The exploration of extrasolar planets, with space telescope like Kepler, revealed a surprising diversity, from massive rocky planets to gaseous mini-Neptune, through water worlds. Although some of them are temperate, other are so much irradiated that their temperature reach the one of late M dwarfs. From Kepler-78 b to TRAPPIST-1 b, through Proxima b, I will revisit the great discoveries of these last years and I will present the landscape of small extrasolar worlds, which diversity is completely amazing.
Abstract
Abstract
Variability is a defining property of AGN emission at all wavebands, with timescales from hours to years depending on the observing window. Optical variability has proven to be an effective way of detecting AGNs in imaging surveys, lasting from weeks to years. We tested its efficiency in selecting AGNs in the VST multi-epoch survey of the COSMOS field, originally tailored to detect supernova events.
We pushed towards deeper magnitude values than in past studies, and compared our results to the ones obtained by means of different selection techniques for AGN identification.
Overall, our approach is able to retrieve a high-purity (83%) sample, which was confirmed by means of a number of multi-wavelength diagnostics. Moreover, the extension of the analysis from a five month to a three year baseline led to a rise in the completeness with respect to the X-ray confirmed AGNs (from 15% to 41%), with a strong dependence on the source apparent magnitude.
This demonstrated the reliability and effectiveness of the method and proved it a powerful tool to be used when, in the near future, the reduction and analysis of much larger amounts of data coming from wide-field surveys will be required.
Abstract
Galaxy nuclei are a unique laboratory to study gas flows. High-resolution
imaging in galactic nuclei are instrumental in the study of the fueling and
feedback of star formation and nuclear activity in nearby galaxies.
Feedback action from star formation and AGN activity is invoked to prevent
galaxies from becoming overly massive, but also to explain scaling laws
like black hole (BH)-bulge mass correlations and the bimodal color
distribution of galaxies. This close relationship between galaxies and
their central supermassive BH can be described as co-evolution. There is
mounting observational evidence for the existence of gas outflows in
different populations of starbursts and active galaxies, a manifestation of
the feedback of activity. We will summarize the main results recently
obtained from the observation of gas flows in a variety of nearby galaxies
with current millimeter interferometers such as ALMA. These observations
have allowed us to image for the first time the very central regions of
nearby AGNs in the submm range with spatial resolutions close to 2-3pc.
Abstract
The European Space Agency's Planck mission was designed to map the cosmic microwave background (CMB) with high precision and high resolution in both temperature and polarization. Maps of the CMB, the heat left over from the Hot Big Bang origin of the Universe, provide values for all the important parameters that determine modern "precision cosmology." I will review the physics underlying such maps, and present the conclusions we can draw from Planck's CMB maps. Note that these results nicely complement other CMB observations now being made by Chilean and North American colleagues at the Atacama Cosmology Telescope near the ALMA site and San Pedro de Atacama.
Abstract
Abstract
Understanding the mechanism driving angular momentum redistribution in protoplanetary disks is essential to understand disk evolution during planet formation. I will present my works combining accurate measurements of mass accretion rates (Macc) with X-Shooter and of disk masses (Mdisk) with ALMA, which showed that viscously evolving disks are compatible with the scatter of Macc observed in 1-3 Myr old star-forming regions only if the viscous timescale is 1-2 Myr. While such long viscous timescales are in principle possible, other scenarios, such as disk wind driven evolution, could also explain the observed scatter. I will also show how I plan to further test these hypothesis with new observations to be taken next week with X-Shooter in the >5Myr old Upper Scorpius region. Finally, I will introduce a new result obtained with Gaia DR2 on the young population in the Lupus V-VI clouds.
Abstract
Since its release the past 25 of April, Gaia DR2 has had a significant impact on the science community. In order to know more about this mission and the science behind it, the JAO colloquium team have invited Dr. Paula Jofre to tell us more about science with Gaia. Dr. Jofre is an Assistant Professor at the University Diego Portales, and she is one of the expert on the Gaia project. Her research interests cover Galactic chemical evolution, analysis of stellar atmospheres, Milky Way structure and evolution, and stellar structure and evolution.
Abstract
Although the number of known exoplanets is just shy of 4000, only a few hundred have precise mass and radius measurements that allow us to investigate their internal structures and compositions.
This is especially true for the Earth-Neptune size domain, where masses and radii have been accurately determined for only a few dozen objects.
The K2 mission is currently providing us with a bonanza of planets transiting bright stars amenable to radial velocity follow-up observations.
In this talk I will present the properties of the K2 planets discovered and well-characterized by the KESPRINT consortium. We are playing a major role in enriching our planet harvest, allowing us to measure the masses of ultra-short period super-Earths with bare rocky cores, mini-Neptunes with volatile-rich envelopes, and long period giant planets.
Abstract
Absolute flux calibration of standard stars, traceable to International System of Units standards, is essential for 21st century astrophysics. Dark energy investigations that rely on observations of Type Ia supernovae and precise photometric redshifts of weakly lensed galaxies require a minimum accuracy of 0.5 % in the absolute color calibration. Studies that aim to address fundamental stellar astrophysics also benefit. In the era of large telescopes and all sky surveys well-calibrated standard stars that do not saturate and are available over the whole sky are needed. Prior work to obtain absolute flux measurements of fundamental standards: Vega, Sirius and others, achieved total uncertainties of 1% to 3%, depending on wavelength.
The NIST Stars program aims to determine the top-of-the-atmosphere absolute spectral irradiance of bright stars to an uncertainty less than 1% from a ground-based observatory. NIST Stars has developed a novel, fully SI-traceable laboratory calibration strategy that will enable achieving the demanding 0.5% requirement. This strategy has three key components: 1) An SI-traceable calibration of the entire instrument system, 2) repeated spectroscopic measurement of the target star throughout the night, and 3) simultaneous measurement of the terrestrial atmosphere. We will discuss this approach, and present results from a pilot study on Mt. Hopkins in Arizona for Vega and Sirius.
Abstract
Abstract
Madrid Cube Analysis (MADCUBA) is a Java-based packaged developed as a plug-in within the ImageJ framework. While ImageJ is new to astronomy, this open source image processing program is designed for scientific multidimensional images, and it is widely used in other science disciplines. MADCUBA offers an easy interface for handling and manipulation multiple datacubes. It is a highly scriptable tool and allows a fast processing of large datasets.
The Spectral Line Identification and Modelling (SLIM) extension within MADCUBA allows the analysis of one dimensional spectra that allows line identification through queries to its stand-alone spectroscopic database. SLIM provides an easy to use infrastructure for synthetic spectra generation as well as automatic fit to observed spectra via Levenberg-Marquardt algorithm. This feature allows the derivation of physical parameter under the Local Thermodynamic Equilibrium approximation.
Though MADCUBA was originally designed to analyze the big datacubes from new generation instruments line ALMA, NOEMA, Herschel and future ngVLA and SKA, it allows manipulation from any instrument through FITS formatted data.
This multi-platform out-of-the-box package has been under development for more than a decade now but it is now open to the community in a stable version. MADCUBA is actually gathering a rapidly increasing number of users. EWASS is an ideal framework for this tool premiere.
I will make an emphasis on the key capabilities of this new package compared to other available spectral analysis tools.
Abstract
I will talk about two recent works studying gas and star-formation in nearby galaxies. First, the ALFALFA HI survey is discovering gas-rich galaxies with almost invisible stellar populations. These (almost) dark galaxies have exceptionally weak star formation and may be related to the recently re-discovered class of "ultra-diffuse" galaxies. Second, we have calibrated a set of indirect cold gas mass indicators using infrared dust emission and gas depletion times. While efficient to observe, these calibrations depend on the molecular-to-atomic mass ratio in the ISM and can significantly over
or under-predict gas masses. These calibrations are useful to extend studies of cold gas to higher redshifts, but require implicit assumptions about galaxy ISM conditions.
April 2018
Abstract
In our ongoing MUSE survey of Galactic globular clusters, we secured about one million spectra for more than 200000 stars so far. The capabilities of MUSE allow us to deblend stellar spectra even in the crowded centres of our targets and thereby open a new window for studying the kinematics in globular clusters. The prospects of the survey are nicely demonstrated by our recent detection of the first detached black hole in a globular cluster, namely NGC3201. We could further show that central rotation is common among massive star clusters, a finding that suggests that all clusters were born rotating. In combination with HST photometry, we are also able to split our samples into the individual populations known to exist inside the clusters and study their kinematics independently. The rotation fields of the various populations may help us to constrain the range of cluster formation scenarios that are currently discussed to explain the presence of multiple populations.
Abstract
Mrk273 is an ultra-luminous infrared galaxy whose nucleus is hidden behind
large curtains of dust. In this type of buried sources, molecular emission is
the best tool to study their nuclei, because it is less affected by opacity
than higher energy photons. I will present NOEMA observations of dense gas
tracers in the galaxy, together with Herschel detections of water. The
combination of millimetre and infrared molecular emission allowed us to study
in great detail the properties of the nucleus, revealing that the rotating
disk around the super massive black hole has two decoupled kinematic
components. I will also discuss the properties of its multi-phase (cold and
warm) molecular outflow, and how it affects the compact core of the galaxy,
making the launching region to expand radially at low velocities.
Abstract
After completion of its final-design review last year, the construction of MOONS - the next generation multi-object spectrograph for the VLT continues full steam ahead. This remarkable instrument will combine for the first time: the 8 m collecting power of the VLT, 1000 optical fibres with individual robotic positioners, and simultaneous medium-resolution spectral coverage from 0.65 - 1.8 μm. Such a tool will allow us to address important questions in Galactic, extragalactic and cosmological fields. In this talk I will present an overview of the instrument, its capabilities and science priorities. In particular, I will provide a brief overview of the plans for one of the surveys to be carried as part of the MOONS consortium GTO, aiming to produce the most detailed chemo-dynamical map of the innermost Milky Way components.
Abstract
Several transiting exoplanets, from Hot Jupiters to Super-Earths, are having their atmosphere investigated with the most powerful technique to date: transmission spectroscopy. This technique measures the wavelength-dependent absorption of starlight by the planet's atmosphere during the primary transit, thereby revealing the atmospheric composition. Ground-based telescopes have successfully probed the atmosphere of exoplanets using this technique. In this talk, I will present my work during my short internship at ESO analyzing FORS2 transmission spectroscopy of the recently discovered super-Earth TRAPPIST-1b.
Abstract
Luminous quasars at high redshift are unique probes to the formation of the earliest supermassive black holes, the evolution of massive galaxies, and the history of cosmic reionization. I will present two recent discoveries of luminous quasars during the epoch of reionization. First, I will discuss the discovery of the most luminous quasar known in the early universe, powered by a 12 billion solar mass black hole, and the implication of the presence of such black hole to the theory of black hole seeding. Then I will discuss the discovery of the most distant known quasar at z=7.5, which yields the strongest constraint on the IGM ionization state during the peak of reionization activities.
Abstract
Abstract
With more than 3,700 planets beyond our Solar system unveiled, and many thousands waiting to be discovered in the upcoming years, the three extremely large telescopes will dramatically advance the study of the composition, dynamics and the structure of exoplanet atmospheres in the next decade. The unprecedented size of these telescope will permit high-contrast imaging of planetary companions to host stars in the Solar neighborhood at orbital separations closer than 1 AU, and high-dispersion spectrographs will open a window to a detailed investigation of exoplanet atmospheres including weather patterns and cloud properties therein. Being capable of inspecting the atmospheres of terrestrial exoplanets, these telescopes will bring us much closer to the answer of one of the most fundamental questions: does life exist beyond Earth?
Abstract
Studying the atmospheres of brown dwarfs gives us insights into the atmospheres of directly imaged planets because they share similar masses, temperatures and gravities, but observations of free-floating brown dwarfs don't need to overcome the high flux ratios between planets and their host stars. Polarimetric measurements can provide a unique handle on cloud properties in both brown dwarfs and exoplanets(e.g. particle size, cloud height, inhomogeneities, etc.), that are degenerate in photometric and spectroscopic measurements alone. Using the new spectropolarimeter upgrade to the WIRC camera on the 200-inch Hale telescope, known as WIRC+POL, we have begun a multi-year survey to measure the NIR polarized spectra of over 100 brown dwarfs. The primary goal of the survey is the characterization of how cloud properties vary as a function of age, spectral type and gravity. The results of the survey will be relevant not only for brown dwarfs studies, but for polarimetric measurements of directly imaged planets as well. Here I will introduce the theory behind the polarization of brown dwarfs, the WIRC+Pol instrument and discuss the survey.
Abstract
Atmospheric composition provides essential markers of the most fundamental properties of exoplanets, such as their formation mechanism or internal structure. New-generation exoplanet imagers have been designed to achieve high contrast for the detection of young giant planets in the near-infrared, but they only provide very low spectral resolutions (R<100) for their characterization. For a major breakthrough in the comprehension of young exoplanets and their atmospheres, an increase of a factor 100 to 1000 in spectral resolution is mandatory. The HiRISE project ambitions to develop a novel demonstrator that will combine the capabilities of two flagship instruments installed on the ESO Very Large Telescope, the high-contrast exoplanet imager SPHERE and the high-resolution spectrograph CRIRES+, with the goal of answering fundamental questions on the formation, composition and evolution of young planets. In this presentation, I will review the interest for direct spectroscopy of exoplanets, what are the current limitations, and how using high-spectral resolution can alleviate some of these limitations. I will present the HiRISE project, the current status and the anticipated developments.
Abstract
I will present ALMA Compact Array (ACA) 870micron data of 28 infrared-bright SDSS quasars at redshifts 2 – 4 with star formation rates beyond 1000 solar masses per year, the largest such sample ever observed with ALMA. The majority of the sources have unique ACA counterparts down to 3" - 4"resolution within the SPIRE 250micron beam, centred on the SDSS coordinates. With only a handful of clear cases of multiple sources within the SPIRE beam, these results are in tension with works on the multiplicity of SPIRE 250micron sources and sub-millimetre galaxies. I will present an extensive comparison between these findings and other recent works and will discuss the implications in the scenario supporting major mergers as triggers of the brightest AGN.
Abstract
Studies of exoplanet atmospheres have revealed a startling diversity between systems, with many showing clouds and hazes which mask pressure-broadened absorption features. In the small sample of planets studied to date, no strong correlation has emerged between key planetary parameters and the presence, or absence, of clouds and hazes, although there is evidence that temperature might play a role. In order to characterise this diversity and unravel the underlying physical processes, it is essential that we expand the current sample of studied planets. This is the focus of the Low Resolution Ground-Based Exoplanet Atmosphere Survey using Transmission Spectroscopy (LRG-BEASTS, “large beasts”). I will present the latest results from LRG-BEASTS which is pioneering the use of 4-metre class telescopes for transmission spectroscopy.
March 2018
Abstract
The Joint ALMA Observatory (JAO) is hosting the Symposium "The ALMA Quest for Our Cosmic Origins" to be held at the JAO offices in Vitacura, Santiago on Tuesday, March 27, 2018. The Symposium is in honor of Pierre Cox service as ALMA Director from 2013 to 2017. Under Pierre's leadership, ALMA transitioned from early science to essentially full operations with all antennas operational, achieving high-profile and stunning science results, including impressive images in many astronomical areas.
The symposium will consist of a series of talks that showcase the latest ALMA results on galaxies, star formation, circumstellar disks, and evolved stars.
Abstract
Only a few decades have been necessary to change our picture of a lonely Universe. Nowadays, red stars have become one of the most exciting hosts of exoplanets (e.g. Proxima b or Trappist-1, Anglada-Escudé et al. 2016, Gillon et al. 2017). However, the most popular techniques used to detect exoplanets (i.e. the radial velocities and transit methods) are indirect. As a consequence, the exoplanet parameters obtained are always relative to the star parameters. The study of stellar pulsations has demonstrated to be able to give some of the star parameters with typical precisions down to 5%, thus accordingly decreasing the uncertainties of the mass and radii estimated for the exoplanets. Theoretical studies predict that M dwarfs can pulsate, i.e. they can drive and maintain stellar oscillations, but no observational confirmation has been reported yet. The Beating Red Dots project uses the HARPS and HARPS-N high-resolution spectrographs with the aim of detecting M dwarfs pulsations for the first time. In this talk I will summarise our results and present our promising candidates.
Abstract
The variety of observations of Active Galactic Nuclei (AGN) show that the nuclear activity is powered by a central massive black hole that drives radio emitting jets and ionizes surrounding line-emitting clouds. This central engine is surrounded by an obscuring torus, comprised of optically thick dusty clouds in a rotating configuration. There is no accepted scenario yet for the dynamics behind this complex environment. In this talk I will suggest that we may get our clues from star formation, the other known case of accretion to a point mass, and present observational evidence in support of this suggestion.
Abstract
Abstract
The Milky Way provides us with a unique opportunity to directly investigate how a galaxy has evolved, from cosmological initial conditions to its present state, by observing the resolved stellar populations of its innermost components. Extensive observations of the highly-obscured, inner regions of the Milky Way are being used to disentangle and characterise the chemo-dynamical and morphological properties of these components. Simultaneously, state-of-the-art simulations are in place to interpret the nature of the observed signatures. Latest results favour a scenario in which internal dynamical evolution of the disc has played the dominant role in shaping the inner parts of the Galaxy into a boxy/peanut-shaped bulge. In this talk I will summarise the implications of these results and show how they can be evaluated against dedicated observations of nearby galaxies, establishing an important benchmark to reconstruct the history of the Milky Way in a global context of galaxy formation and evolution.
Abstract
Under unification schemes, active galactic nuclei (AGN) can be explained by orientation effects. However, some sources show properties at different frequencies that led to incongruent classifications and cannot be explained by such unification scheme. This is the case of PBC J2333.9-2343; its optical spectrum is of a type 2 AGN but its X-ray spectrum does not show signs of absorption, and in the radio it has many features typical of a blazar but it is a giant radio galaxy. Using multiwavelength simultaneous data from XMM-Newton, San Pedro Mártir telescope and VLBA, we find that these classifications cannot be attributed to variability. We propose that PBC J2333.2343 is a blazar that has undergone a restarting activity episode in its nucleus. Interestingly, it has changed from being a radio galaxy to become a blazar, showing an exceptional change in the direction of the jet that, by chance, occurred in the plane of the sky. It also shows a change in the broad line region (BLR) clouds and increasing variability at all observed wavelengths and we have detected an outflow in its optical spectra.
Abstract
This one-week workshop has for objective to bring together the solar system and exoplanet scientific communities and explore how the expertise and recent discoveries in those fields can feed and contrast each other. Strong interactions and collaborations between both communities are essential, as the discovery of exoplanetary systems with a large variety of architectures can teach us about the formation and history of our own solar system, and the deep understanding of our own environment can help us towards our search for life traces outside of the solar system. Various aspects such as formation and architecture of planetary systems, small components of planetary systems, or planetary atmospheres and biomarkers will be discussed from both points of view and in the context of the forthcoming new observational facilities. During this workshop, emphasis will be made on developing new ideas and encouraging synergies between both fields, and plenty of time will be left for discussion and interactions. The main topics and related questions are:
a) Formation of planetary systems and their components: How do theories for the formation of exoplanets affect Solar System formation models? How well do they match the observations?
b) Architecture and evolution of planetary systems: How does the Solar System structure compare to other planetary systems? Why haven’t we yet found a Solar System analog? What are the consequences of planet migration here and beyond?
c) Small components of planetary systems: moons, comets, trojans, asteroid/Kuiper belts, debris disks, rings... Are they the outcome of the formation of planetary systems? What is the status of the search for exomoons, exorings, exotrojans, exocomets and how do they compare with the components in our Solar System?
d) Atmospheres and biomarkers: How do exoatmospheres compare to Solar System planets? What are the prospects for the atmospheres of rocky exoplanets based on Venus/Mars/Earth? How do moon atmospheres compare in the Solar System and what do we expect for exomoons?
Abstract
The Very Large Array (VLA) was, since its completion in 1980, the most powerful and flexible centimeter-wave radio telescope on earth. The EVLA Project, begun in 2001 and completed in 2012, was a major upgrade of the VLA, and has provided astronomers with an effectively new telescope with orders of magnitude increases in sensitivity, spectral resolution, and frequency coverage. To illustrate the fabulous new powers of this upgraded telescope, I will present recent results coming from wide-band observations of the classic high-luminosity radio galaxy Cygnus A. These include the surprising discovery of a transient source just 400 pc from the central black hole, and preliminary results from polarimetric imaging derived via the Rotation Measure Synthesis method. I will conclude with an update on the "Next Generation Very Large Array" (ngVLA), a proposed major high frequency synthesis array, to replace the JVLA sometime after 2025.
Abstract
Magnetic fields are predicted to be an important factor for a wide range of physical processes in protoplanetary disks. In the classical picture, (sub-)mm continuum polarization is the tracer for magnetic fields in disks. Aspherical dust grains, whose thermal emission is intrinsically polarized, get aligned by the magnetic field due to radiative torques. In recent years, however, this picture has been challenged. New theoretical studies show that (sub-)mm continuum polarization can also be created by scattering of the thermal dust emission or arise from aspherical grains which are aligned by the radiation field rather than the magnetic field. These three mechanisms trace fundamentally different physics in protoplanetary disks, yet, their polarisation predictions are not clearly distinguishable. In this talk, I will highlight the role of magnetic fields in protoplanetary disks, present already achieved (indirect) observational constraints, and give an outlook on how to disentangle the sources of continuum polarimetry with ALMA.
Abstract
In twenty-five years, the search for Extrasolar planets gained a remarkable momentum. The goal of detecting and characterizing the population of Earth-mass planets around the Sun led to the development of dedicated instrumentation, like high-resolution and high-precision spectrographs.
In this talk I will review several projects I am involved in and that can be of interest to many of you: ESPRESSO, NIRPS, HELIOS, SPIRou. The specifications of these instruments make them very useful for a wide range of topics other than Extrasolar planet research. I will also briefly discuss some of the latest works I performed with my collaborators on the impact of activity on planetary detection. As a new ESO Staff I would like to discuss opportunities for synergies, both on the exploitation of instrumentation opportunities and on focused scientific goals.
February 2018
Abstract
The formation of the central regions of disk galaxies that we call galactic bulges remains a debated topic in modern galaxy evolution.
In this respect, the bulge of the Milky Way offers a unique opportunity to investigate in detail the role that different processes (secular evolution, dynamical instabilities, hierarchical merging, dissipational collapse etc..) may have played in the Galaxy formation and evolution. Indeed, it is only in the bulge of the Milky Way that all stars can be individually resolved, allowing to correlate the global structural properties of the bulge with the characteristics of its stellar population, such as age, chemical content, and kinematics. However, this advantage comes with the need of covering a large area on sky (~500 sqdeg). In this respect, large observation programmes and surveys are now providing a global view of the bulge stellar population properties that can be used to constraint formation and evolution models.
I will review our current understanding of the three-dimensional structure, chemical composition, age and kinematics of the bulge as obtained from some of the recent photometric and spectroscopic surveys.
Abstract
During two weeks of intense work the participants will have the chance to have hands-on real-life experience on the full cycle from proposal preparation to data reduction. Participants will be divided in 5 groups of 4. During the whole school, each group will be guided by a tutor and possibly by a tutor assistant.
After a preparatory work done at the ESO Headquarters in Chile, where the students will have lectures on the basics of observing techniques and how to prepare observations for ESO telescopes, the group will go up to the La Silla Observatory for three nights of observations with the ESO NTT and the Danish 1.54-m telescopes. Back in Santiago with the data in hand, the participants will reduce and analyse their datasets.
While having lectures on hot-topics of present day astrophysics, the teams will prepare their presentation of their results to the ESO audience. Additional training on aspects of career development is also foreseen.
Abstract
While it is undisputed that a Supernova type Ia explosion occurs when
a white white star surpasses the Chandrasekhar mass limit, it is
embarrasing that we still do not have a full understanding of the
pathways leading to the ignition. This uncertainty may, ultimately,
limit the precision of SN Ia based cosmology and hence our understanding
of the nature of dark energy.
One viable channel, the single degenerate channel, involves accreting
white dwarfs in binary systems, where the white dwarf mass grows by
steady shell burning of the hydrogen accreted from a close and more
massive companion.
Here I demonstrated how we can further develop our understanding of
mass growth by studying systems that are about to undergo a hydrogen
shell burning phase and those that came out from this phase, in
which the white dwarf failed to reach the critical ignition mass.
The white dwarfs in the latter systems are the dominant source of light
in the ultraviolet. The photospheric abundances of these accreting white
dwarfs reflect the composition of their companion stars. My analysis
of the HST/COS spectroscopy reveals highly anomalous abundances, in
particular extremely large N/C ratios. Evolutionary sequences computed
with MESA to reproduce the abundances can constrain initial binary
parameters of the progenitors, and constraints to the parameter space
of binaries that will enter the single-degenerate channel.
Abstract
Abstract
Theoretical models of galaxy evolution suggest that the presence of an active galactic nucleus (AGN) is required to regulate the growth of its host galaxy through feedback mechanisms. Even if observational studies have revealed that AGN-driven kpc-scale outflows are common both at low and high redshift, a comprehensive picture is still missing. I will talk about an ongoing ESO’s VLT/SINFONI Large Programme, SUPER (a SINFONI Survey for Unveiling the Physics and the Effect of Radiative Feedback), which aims at investigating ionized outflows in a representative sample of 40 AGN at z~2. SUPER is designed to map the gas kinematics ([OIII] and Ha emission lines) on kpc scales, using integral-field spectroscopy and exploiting adaptive optics capabilities. I will present the survey overview and the target sample properties as well as an ongoing ALMA program, complementing the SINFONI data, which allows us to characterize the molecular gas content of the hosts.
Abstract
Star formation mostly takes place in star-forming galaxies (SFGs) from high-z to the present day. The tight correlation between star formation rates (SFRs) and stellar mass, namely the main sequence of SFGs, has become one of the fundamental relationships to test models of galaxy formation and evolution. Characterizing the slope, normalization and scatter of the main sequence provides key insights into the physical processes regulating star formation in galaxies. I will present recent observational progress in measuring features of the main sequence of SFGs across cosmic time, and discuss implications for understanding bursty star formation histories of low- and high-mass SFGs, relative roles of in situ star formation versus mergers in driving galaxy mass assembly, and effects of bulge growth on galaxy star formation.
January 2018
Abstract
My research deals with high-precision Doppler detection and characterization extrasolar planets. I am involved in a number of radial velocity surveys, which goal is to discover planetary companions around: Solar type (HARPS, FEROS), M-dwarf (CARMENES) and evolved intermediate mass stars of spectral type G and K (Lick/Hamilton). will introduce these Doppler programs and I will present several of our discoveries. Since my primary research is dynamical stability of multiple planet systems I will
focus on few spectacular mean motion resonance (MMR) multi-planetary systems discovered in our data. You will learn about the dynamics and long-term stability of these systems and I will discuss the possible channels to form their MMR orbital configurations.
Abstract
Abstract
A brief history of the development of stellar interferometry
since its inception is provided. I aim to describe the contributions to
the technique by the pioniers, i.e. Fizeau, Michelson, Labeyrie and
present in tandem the astrophysical developments that drove the
technical innovations. This TMT adds to previous TMTs on astrophysical
results obtained with stellar interferometry by various colleagues. I
hope this presentation raises your interest and helps to place stellar
interferometry in a more extended astrophysical context.
Abstract
My talk will be aimed at a general audience, so I hope all ESO staff, scientists, engineers and the support staff will take something from it. I will describe the motivation for and the current status of the Square Kilometre Array. The SKA Observatory, which will consist of two next-generation radio telescopes, located in Australia and South Africa, is being designed to answer some of the fundamental scientific questions of our time: why does the Universe look like it does now? How does Einstein’s theory of General Relativity interact with the quantum world? What is the origin and influence of magnetism in the universe? Where does life originate? And many more.
I will describe the current work on designing the SKA, including the prototype dishes under construction in China, the low frequency antennas being deployed in Australia, and the digital and software solutions being developed to cope with the deluge of data that the SKA will generate. I will also talk about the current state of discussions in governments as we set up a new inter-governmental organisation in astronomy.
Abstract
Abstract
Relativistic jets are feeding radio lobes on spatial scales many time larger than the host galaxy, they are interesting laboratories and probes of many different environments and time scales. Starting from the outermost regions and zooming onto the jet base, I will review some of the recent results in the field. In particular, with increasing resolving power, I will discuss the presence of jet structures in blazar and radio galaxies, focusing in particular on M87 and 3C84. The use of space VLBI (on the latter) and of mm-VLBI (the "Event Horizon Telescope", on the former) are permitting to reach spatial resolution of tens to hundreds Schwarzschild radii, and thus probing the black hole vicinity and the region of jet formation with unprecedented detail. This also has important connection to the high energy emission from jets, which I will also shortly discuss.
Abstract
Abstract
Abstract
We resolved FU Ori at 29-37 GHz using the JVLA with $\sim$0$''$.07 resolution, and performed the complementary JVLA 8-10 GHz observations, the SMA 224 GHz and 272 GHz observations, and compared with archival ALMA 346 GHz observations to obtain the SEDs. Our 8-10 GHz observations do not find evidence for the presence of thermal radio jets, and constrain the radio jet/wind flux to at least 90 times lower than the expected value from the previously reported bolometric luminosity-radio luminosity correlation. The emission at $>$29 GHz may be dominated by the two spatially unresolved sources, which are located immediately around FU Ori and its companion FU Ori S, respectively. Their deconvolved radii at 33 GHz are only a few au. The 8-346 GHz SEDs of FU Ori and FU Ori S cannot be fit by constant spectral indices (over frequency). The more sophisticated models for SEDs suggest that the $>$29 GHz emission is contributed by a combination of free-free emission from ionized gas, and thermal emission from optically thick and optically thin dust components. We hypothesize that dust in the innermost parts of the disks ($\lesssim$0.1 au) has been sublimated, and thus the disks are no more well shielded against the ionizing photons. The estimated overall gas and dust mass based on SED modeling, can be as high as a fraction of a solar mass, which is adequate for developing disk gravitational instability. Our present explanation for the observational data is that the massive inflow of gas and dust due to disk gravitational instability or interaction with a companion/intruder, was piled up at the few au scale due to the development of a deadzone with negligible ionization. The piled up material subsequently triggered the thermal and the MRI instabilities when the ionization fraction in the inner sub-au scale region exceeded a threshold value, leading to the high protostellar accretion rate. We note that this mechanism may resolve the missing-disk-mass problem when comparing with the exoplanets identified by Kepler satellite.
Abstract
In November, I talked about the possibility of finding exoplanet life from biogenic atmospheric gases. But a more basic question is whether a planet will even have an atmosphere. Within the Solar System, there are odd couples. Titan and Ganymede are of similar mass but have thick and negligible atmospheres, respectively. Venus and Earth are comparable in mass overall but their atmospheric masses differ by ~2 orders of magnitude. In general, the end-states of atmospheres must depend on volatile-rich origins and subsequent evolution. The latter is critical. Solar System planets and moons divide into those with and without atmospheres when plotted by insolation versus escape velocity to the fourth power, while exoplanets with probable atmospheres crowd under an extrapolation of this trend. This relationship probably occurs because irradiation-driven hydrodynamic escape of atmospheres is common. On the other hand, atmospheric erosion by large impacts can also be important. Empirically, impact erosion obliterates atmospheres when the median impact velocity reaches ~5 times a planet’s escape velocity or more. Unfortunately, thermal evaporation or impact erosion is potentially bad for planetary atmospheres in the habitable zone of the most common stars, i.e., M stars. There, atmospheres endure high impact velocities and pre-main-sequence thermal evaporation. Whether such planets could subsequently support life is unclear. I conclude that, in essence, rocky planet atmospheres are like the ruins of medieval castles: remnants of riches that have been subject to a range of plunder. Future exoplanet data will have much to bear on the issue.
Abstract
Abstract
Globular cluster (GC) formation is a major unsolved problem in astrophysics. A new constraint on the problem came from the discovery of unexpected star-to-star variations in the abundances of some light elements like, e.g. He, C, N, O, Na and Al. These abundance variations (or multiple stellar populations, MPs) are ubiquitous to all GCs studied to date. The pursuit to explain this longstanding problem using these new constraints (i.e. the MPs), has reinvigorated the study of GCs, and at the same time has challenged our understanding of nucleosynthesis and stellar evolution. For this talk I will give an overview of the challenges current GC formation scenarios face.
Abstract
In this talk I will present two large optical photometric surveys, J-PLUS and J-PAS, carried out at the OAJ observatory, a dedicated facility in continental Spain. J-PLUS, which has already observed few hundreds of square degrees, is scanning the sky with twelve filters, a carefully chosen mix of broad- and narrow-band filters able to capture unique spectral features. I will present the first science verification results, from the IFU-like analysis of local galaxies, to high-redshift emission galaxies and quasars and the detection of metal-poor stars. I will then present forecasts for the J-PAS survey, which will start at the end of this year to observe thousands of square degrees with 54 narrow-band filters covering the entire optical range. Its high spectro-photometric resolution, the wide area covered and the unprecedented depth, will make J-PAS a very powerful tool to unbiasedly study the diversity of galaxies across cosmic time.
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