One of the main objectives in the field of extragalactic astronomy is to understand the connection between galaxies and the distribution of the underlying dark matter. In order to understand the physics behind baryonic processes that can affect the distribution of dark matter, models need observational constraints. I will present measurements of the stellar mass content of 10 rich clusters in the Gemini Cluster Astrophysics Spectroscopic Survey (GCLASS) around redshift z~1. We find that the stellar mass fraction at fixed halo mass shows no significant evolution towards lower redshift clusters. However, the spatial distribution of stellar mass in these haloes appears to evolve significantly. We measure a relatively high NFW concentration parameter c~7 for the stellar mass distribution in these clusters, and debate a possible scenario to explain the evolution of the stellar mass distribution from the GCLASS sample to their likely descendants at lower redshift.

Spectroscopic observations of galaxies provide us with the information about their internal kinematics and stellar populations. Internal kinematics of a galaxy imprints current dynamical state, while stellar population keeps a fossil record of the star formation history that both become crucial for understanding galaxy evolution. I will briefly review data analysis techniques used to extract internal kinematics and properties of unresolved stellar populations. Also I will present our method for simultaneous analysis of spectroscopic and photometric information. The advantages and disadvantages of different techniques will be considered.

Absorption lines from galaxies at intervening redshifts in quasar spectra are sensitive probes of metals and gas that are otherwise invisible due to distance or low surface brightness. However, in order to determine the environments these absorption lines arise in, we must detect these galaxies in emission as well. Galaxies on top of quasars (GOTOQs) are low-z galaxies found intervening with background quasars. These galaxies have been flagged for their narrow galactic emission lines present in quasar spectra in the SDSS.

Typically, the low-z nature of these galaxies allows them to be easily detected in SDSS imaging. However, a number of GOTOQs (about 30%), despite being detected in spectral emission, are NOT seen in SDSS imaging. This implies that they may be dark galaxies, dwarf galaxies, or similarly low surface brightness galaxies. Additionally, about 25% of those detected in imaging are dwarf galaxies according to their L* values. Dwarf galaxies have long been underrepresented in observations compared to theory and are known to have large extents in dark matter.

Given their prevalence here in our sample we must ask what role they play in quasar absorption line systems (QSOALS). Recent detections of 21-cm galaxies with few stars imply that aborted star formation in dark matter sub-halos may produce QSOALS. Thus, this sub-sample of galaxies offers a unique technique for probing dark and dwarf galaxies. The sample and its properties will be discussed, as well as prospects for the future.

Multiple stars are an inevitable, if not necessary outcome of the star-formation process. Their investigation, in particular in young star-forming regions where dynamical processing might not have removed all signatures of the primordial orbital and environmental parameter distributions, puts valuable constraints on the mechanisms at work during the first stages of a (multiple) star's life. In this talk I will present results of a large, coherent survey for sub-stellar companions and stellar multiplicity of the 1Myr-old Taurus star-forming region. Due to our deep sensitivity limit of ~1 MJup and minimum separations of <~20 AU at the distance of Taurus, we detect more than 90 (stellar, brown dwarf, and planetary) companion candidates close to ~50 stars. Follow-up observations were conducted to confirm part of these systems as physically bound. The resulting statistics of the binary frequency, mass ratios, and separations are put into context with recent results from other nearby young star-forming regions to draw conclusions about the processes involved in the formation of stars and planets. For example, it appears that the detected low frequency of brown dwarf companions is consistent with stars and brown dwarfs forming through the same process.

Nearby AGN NGC 4258 displays strong 22 GHz water maser emission, which enables mapping of a circumnuclear disk at the 40 000 Schwarzschild radius level (within 1 pc of the supermassive black hole). In this talk, I will discuss how we have used the masers to investigate the Unified Model for AGN. I will also describe how we have used the masers to make a new, high-accuracy geometric distance measurement to the galaxy. With this measurement, we have re-anchored the extragalactic distance scale of Riess et al. (2011) and obtain a Hubble constant of 72.0 ± 3.0 km/s/Mpc.

In a recent text book (Beckmann & Shrader, 2012) we are discussing in depth the status of AGN research, the open questions and possibilities to answer them. In this presentation I will focus on the main open issues concerning the central engine of AGN. Is the central black hole rapidly spinning and can we proof this? What is the dominating accretion mechanism in AGN? Why do some AGN form jets and others don't and how do the jets start off? Is the emission of blazars dominated rather by synchrotron self-Compton or by external Compton processes? I outline the status of related research, formulate the questions and try to hint at research projects able to tackle these fundamental topics.

Massive star magnetism is often considered an astronomical "wildcard", as it is hard to predict in which stars it may occur. This reflects our fundamental ignorance of the origin of massive star magnetism, and compels us to better understand the scope of its influence on massive stars individually, and also as a population. In the last decade, our understanding of this phenomenon has made a giant leap forward thanks to a new generation of powerful spectropolarimeters capable of measuring the Zeeman effect in the spectra of these stars. Over the past 5 years, ambitious projects such as the Magnetism in Massive Stars (MiMeS) Collaboration have been seeking out magnetic massive stars in the Galaxy, to better understand their origins, physical properties, and how they influence observable stellar characteristics. This presentation will review our current understanding of the impact of magnetism on the lives of the most massive stars.

Disk galaxies play a fundamental role for our understanding of the now generally adopted cosmology according to which the Universe is dominated by Dark Energy and Dark Matter. An important tool to test predictions of simulations based on this concordance cosmology are so-called scaling relations that link fundamental parameters of disks like rotation velocity and luminosity (-> Tully-Fisher Relation) or rotation velocity and size. Using deep spectroscopy with the Very Large Telescope and imaging with the Hubble Space Telescope, we have constructed a data set of several hundred disk galaxies that span more than half the age of the Universe and a variety of environments. With this sample, utilizing scaling relations like the Tully-Fisher, I will show how the disk galaxy population evolved over the past 8 Gyr, how stellar population properties relate to galaxy masses, and how transformations between different galaxy types might occur in galaxy clusters.

Recent work shows that SN Ia are better standard candles in the near IR than at optical wavelengths. Even better, the vexing problem of dealing with dust absorption and intrinsic color variations is simpler in the IR. In the past year, we have used PanSTARRS to discover 24 supernovae at 0.2

The concept of angular momentum in galaxies is about to penetrate mainstream astronomy thanks to phenomenal progress in integral field spectroscopy and supercomputing capabilities. This talk presents high-precision measurements of the specific baryon angular momentum, contained in stars, atomic gas, and molecular gas, in 16 nearby late-type galaxies of the THINGS sample. A strong, irreducible correlation is found between mass, angular momentum, and morphology traced by the bulge mass fraction. I will discuss the origin of this relation using geometrical scaling relations coupled with stability considerations. I will also discuss how mass and angular momentum link to classical empirical relations, such as the fundamental plane for spiral galaxies, the Tully-Fisher relation, and the mass-size relation. These results advocate the regular use of angular momentum in classifying and modelling galaxies.

The thermal infrared domain (8-1000 microns) contains half of the relic light emitted during structure formation. This emission is mainly caused by dust heated by young stars in star-forming galaxies at high redshift and called Cosmic Infrared Background (CIB). Identifying and characterizing the objects responsible for this emission is thus crucial to built a consistent picture of star formation in the Universe.

Thanks to its very good sensitivity, Herschel allows to resolve directly the CIB into individual sources in the far-infrared, and obtain some statistical constraints on these objects in the sub-millimeter. These observations showed a "main-sequence" of star-forming galaxies (i.e. a strong correlation between star formation rate and stellar mass). Starting from observed “main sequence” of star-forming galaxies and adding a population of merger-driven starburst, we managed to reproduce the galaxy number counts from mid-IR to the radio.

We then extended our model to clustering measurements (CIB fluctuations, angular correlation function of resolved galaxies), using the correlation between the stellar mass and the halo mass of galaxies. This model well agrees with the measurements of auto- and cross-power spectrum of the CIB anisotropies measured by Planck, Herschel, SPT and ACT, but also the CIBxCMB lensing signal detected by Planck. This model predicts that star formation efficiency is maximal for a mass of 10^12 Msun at all redshift. If we take into account the halo growth, this implies that CIB is dominated by galaxies in future clusters (log(M)>13.5 Msun at z=0) at z>5, of groups (12.5

Globular clusters were once thought to be simple stellar populations. However, in recent year it has become clear that each cluster contains different populations with specific abundance patterns. The most striking ones are multiple main sequences (indicating different He-abundances), the Na-O anti-correlation and the Mg-Al anti-correlation.

This has been interpreted as a sign that each cluster had several episodes of star formation, i.e. multiple generations, where each new generation is formed from mass ejected by evolved stars. The proposed polluters are: AGB stars, rapidly rotating massive stars, and interacting massive binaries. This interpretation has several serious problems: a mass budget problem, a gas-retention problem, an IMF problem and a Li-problem.

I will briefly discuss the observations and the models with their specific problems and uncertainties. I then suggest a new model in which the observations are explained by one single star forming event with the low mass stars polluted by ejecta from the massive stars of the same event. This model overcomes some of the serious shortcomings of the multiple generation models. I will discuss uncertainties of this model, and possible observational tests. (reference: Bastian et al. 2013, arXiv1309.3566)

Accretion is one of the dominant sources of radiation from a low mass young stellar object for the first few million years. This process regulates the flow of material and angular momentum from the surroundings to the central object, and is thought to play an important role in the definition of the long term stellar properties. Variability is a well documented attribute of accretion, and has been observed on time-scales ranging from days to years.

My thesis set out to use the intrinsic accretion variability to probe the inner regions of these systems. Two spectroscopic surveys were utilised that concentrated on the H-alpha emission line, which is known to be closely connected to the accretion process. Together, these surveys covered 24 object including low mass T Tauri, intermediate mass T Tauri stars and Herbig Ae stars, on time-scales of minutes, days, weeks, months to years. These two studies found the accretion variations to be less than half an order of magnitude and dominated by time-scales close to the rotation period. A further photometric monitoring campaign was undertaken to confirm the short term variations found in the low mass sample.  
I will present the results of these studies, and argue that they imply that the majority of the variations in typical accreting objects are the result of an asymmetric accretion flow. 

Interstellar extinction is a key method by which we study the dust content of the universe. A correct interpretation of extinction therefore depends upon our understanding of systematic effects. I will briefly review extinction, highlighting the potential for geometry- and resolution-dependent effects to introduce important systematics. I will follow by introducing the numerical techniques we used to investigate and quantify these effects. The results of a number of radiative-transfer simulations will be presented, quantifying the impact of unresolved clumpyness on the observed extinction curve both toward embedded objects and in the diffuse ISM. These models show that changes in the geometrical distribution of the dust can cause significant changes in the shape of the extinction curve, and hence the extinction curve is not a robust probe of the properties of dust in the ISM.

I will review standard views about the energy sources of the molecular gas in galaxies, and their impact on H2 gas mass estimates. I will then present a new picture currently being assembled from analysis of Herschel/FTS data and a large CO, 13CO, and HCN ground-bases survey of Luminous Infrared Galaxies with the JCMT and the IRAM 30-m telescope. Finally I will briefly discuss some implications regarding the Xco factor and the so-called bimodal star formation in mergers and disks.

The first of the Square Kilometre Array (SKA) precursor telescopes in Western Australia is now operational. The first data was taken on August 5 for the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, for which I am PI. Deep EOR observations are also underway. The second precursor, the Australian SKA Pathfinder (ASKAP) begins early science operations in 2015, and full operations shortly after. I will give an update on both of these projects and discuss progress with the international SKA project.

We present the novel technique for the determination of the low-mass end slope of the present day stellar mass function (PDMF) of unresolved stellar populations using pixel fitting of spectra integrated along the line of sight. In stellar systems with long dynamical relaxation timescales, where one can neglect the effects of the dynamical evolution, the PDMF is identical to the IMF at low masses. Our method achieves precision of ~0.1 in MF slope value and hence outperforms classical IMF determination techniques which use direct star counts in open clusters and HII associations. We used our method to obtain IMF for a few GCs and UCDs and 3000 giant elliptical galaxies. We do not see any evidence that the low mass IMF slope in giant ellipticals depends on their mass.

As a massive protostar forms it is expected to go through phases dominated by Outflow and Radiation. In this talk, it will be explored if these two phases can overlap.
This is achieved through the construction of  an evolutionary scheme which tracks protostellar structure, the environment, the inflow and the radiation feedback.  We investigate constant, decelerating and accelerating accretion rate scenarios and consider both hot and cold accretion, identified with spherical free-fall and disk accretion, respectively. We find that neither spherical nor disk accretion can explain the high radio luminosities of many protostars. Nevertheless, we discover a solution in which the extreme ultraviolet flux needed to explain the radio emission is produced if the accretion flow is via free-fall on to hot spots covering less than 20% of the surface area. Moreover, the protostar must be compact, and so has formed through cold accretion. This adds support to the models in which  massive  stars form via gas accretion through disks which, in the phase before the star bloats, download their mass via magnetic flux tubes on to the protostar.

In the context of galaxy evolution, it is particularly interesting to understand better the mechanisms that regulate starburst activity in galaxies. In this talk I will present an analysis of the molecular ISM properties in the prototypical circumnuclear starburst galaxy, NGC 253, derived from ALMA observations. I will discuss the evidence for a molecular superwind, our measurements of the mass loss rate, and the possible gas entraining mechanisms. I will show our measurement of the properties of giant molecular clouds in the starburst, in an effort to better understand the conditions in the starburst. Finally, I will present and discuss some of the chemical complexity we see in the data. This extremely rich spectroscopy, a common feature in many ALMA datasets, opens new windows for the study of physical conditions in extragalactic systems.

The Cepheid method to determine distances to spiral galaxies, and its
principal sources of systematic error is reviewed. I will report on
recent work of our Araucaria Project group to reduce the most serious
source of uncertainty of the method, the distance to the Large
Magellanic Cloud, to 2% using late-type eclipsing binaries. We have
discovered a number of such systems which contain Cepheid variables
and present a unique opportunity to derive the physical parameters
of the Cepheids with unprecedented accuracy. I will show that this
has led to the resolution of the long-standing Cepheid mass discrepancy
problem. Finally, I will report on a very recent accurate determination
of the distance to the Triangulum galaxy M33 from infrared photometry
of Cepheid variables, and show that the value of the Hubble constant
based on our accurate LMC distance from eclipsing binaries might be consistent,
within the respective 1 sigma errors, with the recent Ho determination
from the Planck satellite.

Observational evidence suggests that a significant fraction of Type Ia Supernovae progenitors shape their environment prior to explosion. The circumstellar medium expected from different progenitor models may provide a way to differentiate between the channels. A model for the circumstellar medium as shaped by a recurrent nova is presented and compared with observations. The model shows good agreement with observations of the galactic recurrent nova RS Ophiuchi and is discussed in terms of the observations of Type Ia Supernovae.

The formation time, masses, and location of planets are strongly impacted by the physical mechanisms that disperse protoplanetary disks and the timescale over which protoplanetary material is cleared out. Accretion of matter onto the central star, protostellar winds/jets, magnetic disk winds, and photoevaporative winds operate concurrently. Hence, disentangling their relative contribution to disk dispersal requires identifying diagnostics that trace different star-disk environments.

In this talk, I will analyze the low velocity component (LVC) of the Oxygen optical forbidden lines from a large sample of protoplanetary disks and compare this diagnostic with other disk dispersal indicators. Our results suggest that the [OI] LVC traces the disk layer where OH is photodissociated by stellar FUV photons. Part of that layer is gravitationally unbound and leaves the star/disk system in the form of a wind. I will discuss the origin of these winds in the framework of theoretical predictions for magnetically driven and photoevaporative winds.

Small temperature and density fluctuations in the early Universe
have grown into the cosmic web of dark matter and barionic matter
that we see today.  Matter is distributed among large-scale filaments,
punctuated by galaxy clusters at the intersection points of this
web.  Mapping the cosmic history of rich galaxy clusters provides
fundamental information about both cosmology and galaxy formation.
I will describe our panchromatic studies of X-ray and infrared-selected
galaxy clusters and groups at high redshift.  These studies enable
us to trace the first stages of galaxy evolution in high density
environments.  In this talk, I will discuss the role of the environment
on both the structural properties and stellar populations in massive
galaxies in rich, high-redshift environments.

We have a selected a sample of over 100 gravitationally lensed dusty star forming galaxies from the 2500 square degree South Pole Telescope survey. Using APEX/LABOCA and Herschel, we have determined their IR SEDs. ALMA Cycle 0 molecular line spectroscopy and imaging have characterised this population, and found that they have a median redshift =3.5, while previous surveys found =2.5. While based on only 23 redshifts thus far, this difference is very significant, and can already distinguish between different flavours of galaxy formation models. We are continuing the redshift search of the lensed galaxies in ALMA Cycle 1, and of the lensing galaxies with X-shooter. Follow-up observations of our sample include [CII] lines with APEX and Herschel, and low-J CO lines with ATCA. This combination is providing a first statistically significant sample of the physical conditions in the ISM at redshifts up to 5.7.

Unification by orientation is a ubiquitous concept in the
study of different types of active galactic nuclei (AGN). In these
models, various types of AGN are in fact intrinsically the same but
appear as different classes due to different viewing angles relative to
the line of sight.

This picture has historically been used to unify radio galaxies and
radio-loud quasars. A simple prediction of this model is that the
projected size of radio structure in radio galaxies should appear larger
than that of radio-loud quasars, because radio galaxies are seen at a
larger inclination relative to the radio jet axis. This was in fact
observed two decades ago; however, newer and larger samples have
revisited this question and found conflicting results.

An assumption in this projected size test is that the intrinsic sizes of
radio galaxies and radio-loud quasars are the same. However, it is
unlikely that there is a single intrinsic size, but instead the sources
are drawn randomly from an underlying distribution. I will discuss
simulations that test whether contradictory results regarding the
projected sizes of these sources can be reconciled by random sampling of
several intrinsic size distributions.

The Panchromatic Hubble Andromeda Treasury (PHAT) survey is obtaining six filter Hubble Space Telescope imaging of ~1/3rd of the Andromeda galaxy disk. The survey is nearly complete and promises to reveal the most extensive star cluster system known in any galaxy. I will discuss the "Andromeda Project", our crowd sourcing project to identify star clusters in the PHAT data. We are using these clusters to study the formation of stars, including the stellar and cluster initial mass functions, and the efficiency of star cluster formation.

Our universe has passed the peak of star formation activity. Galaxies are accelerating away from each other, and their evolution is becoming more dominated by secular proceses. Indeed, observations show that galaxy disks have reached an equilibrium stability throughout their optically bright portions and beyond. I will show that the assumption of a uniform stability provides a good model for the structure of present day disk galaxies. It allows us to resolve some long known puzzles and provides a bridge between star formation, the gas and dark matter within galaxies. I will describe our current work on the constant stability disk models and prospects for understanding the main-sequence of star forming galaxies and their evolution.

Direct imaging mitigates selection effects inherent to the currently known exo-planetary population since it is sensitive to objects in an orbital space orthogonal to the one available with indirect methods. Upcoming campaigns will survey young and adolescent stars and probe for signatures of their formation history using instruments designed for high-contrast imaging. In the first part of this presentation I will discuss the wealth of information accessible using such surveys. I will describe current methods and ongoing projects aimed not only at identifying exo-planetary systems but also at estimating their bulk physical properties and atmospheric chemistry. I will in particular highlight our recents results, obtained using both the HST NICMOS Archive and the Project 1640 Integral Field Spectrograph installed at the Palomar Hale Telescope, that provide new insights regarding the true nature of a known exo-planetary system. Direct imaging is moreover envisioned as the preferred method to search for biomarkers in the atmosphere of earth-analogs, and answer one of humanity's most ancient questions "Are we alone?". This endeavor presents daunting technical challenges: such science requires to detect a planet whose signal is ten order of magnitude fainter than its host star. In the second part of this presentation I will review recent progress in high-contrast coronagraphic technologies spurred by this ambitious goal, with a particular emphasis on our work in high-precision modeling and experimental demonstration of phase induced amplitude modulation concepts. Technology demonstration efforts in this field have been focused on un-obscured off-axis apertures, because of the long standing belief that light diffracted by the secondary support structures and segment gaps would be a major hindrance to reaching the desired contrast. This places considerable constraints on future observatory architectures. I will present a solution to this problem and show that, using concepts and technologies already developed for monolithic un-obscured telescopes, high-contrast can in principle be achieved with any aperture geometry, even in the presence of a central obscuration and segment gaps.

The Hawk-I UDS and Goods Survey (HUGS) is the result of an a ESO Large Program that has just been completed.
It exploits the unique capabilities of Hawk-I to collect the deepest Near-Infrared images ever obtained over an area of about 1/10 os square degree, i.e. large enough to be representative of the high redshift Universe.
The survey is focused on two extragalactic fields (UDS and GOODS-S) where deep multiwavelength data are also available, especially those coming from the HST Treasure Program CANDELS. Combined with UltraVISTA, this survey will constitute an invaluable, probably definitive, legacy from ESO instrumentation ahead of the advent of E-ELT and JWST.
I will present the final data set and show early science results, showing that the HUGS data are be decisive to i) locate and measure the Balmer break at high redshift, in order to properly measure masses, ages and dust content at z > 4; ii) assemble the first complete sample of galaxies at z > 4, without the limitations of UV-selected samples, and iii) decisively secure redshift estimates for the most elusive objects at z > 4, like quiescent or evolved Lyman-Break Galaxies.

Nearby blue compact galaxies are a subgroup of starbursts that constitute ideal laboratories to test in detail the interplay between massive star formation and the surrounding gas, under similar conditions to those occurring when galaxies were forming. Given its proximity and the wealth of ancillary information available in all spectral ranges, a particularly well-suited example for the study of this interaction is NGC 5253.

We are carrying out a detailed analysis of the central region of NGC 5253 using optical integral field spectroscopy. The outcome of this work has been published in Monreal-Ibero et al. 2010, 2012, 2013 and Westmoquette et al. 2013. In this talk I will review the results presented so far. Among other topics, I will address the 3D structure of the physical properties (electron density, temperature and excitation) of the ionized gas. Also, I will present mapping of its chemical content and the relation with the Wolf-Rayet star population of this galaxy. Two elements, deserving a detailed discussion, will be highlighted: nitrogen and helium.

The Orion molecular cloud 1 (OMC-1) is a unique environment for the study of interstellar chemistry, especially in the surroundings of the Orion BN/KL region. As one of the closest star-forming regions, many complex molecules have been detected toward Orion BN/KL, including a few deuterated molecules. In this talk, I will present the recent results from our IRAM PdBI observations and focus on two molecules, deuterated methanol CH2DOH and acetone (CH3)2CO. I will also discuss the deuterium chemistry and nitrogen/oxygen-differentiation in Orion BN/KL and their future prospects in the ALMA era.

Recent results by the space-based NASA's DIXI and Japanese Akari missions demonstrated that the carbon chemistry in comets remains incompletely understood. DIXI found that the outgassing in comet 103P/Hartley 2 was driven primarily by carbon dioxide. The Akari survey of 18 comets revealed a significant abundance of CO2, but surprisingly it detected only upper limits for carbon monoxide in most comets comprising their sample. Our recent ground-based VLT/CRIRES observations showed a relative large amount of CO in Oort cloud comet C/2009 P1 (Garradd) at 2 AU, and also in the border-line Jupiter Family/Centaur comet 29P/Schwassmann Wachmann 1 at 6.3 AU. In this presentation, I will report these detections, compare them to existing studies, and explore possible links between chemical composition and cometary origins.

I present an algorithm for speckle holography that has been optimised for crowded fields. The algorithm was tested on a range of different instruments and targets and from the N- to the I-band. In terms of PSF cosmetics and stability as well as Strehl ratio, holographic imaging is equal to, if not superior, to the capabilities of most, currently available AO systems. It outperforms classical lucky imaging. Holography can relatively easily deal with anisoplanatic effects in dense fields. I will present the exciting results of our tests and will discuss the virtues and vices of the technique. In particular I will address the question in which situations holography can provide unique advantages, or present an alternative or complementary method to the more established techniques such as standard AO imaging or sparse aperture masking.

The widely used reference mass-metallicity relation (MZR) at z>2 from the Erb et al. (2006) study has been affected by the sample selection and unknown AGN contribution, and was based on limited spectroscopic information (1-2 emission lines), yielding large uncertainties in metallicities.To better constrain the MZR of galaxies at z>2, we used VLT and SUBARU near-infrared spectroscopy to measure, for 22 MS galaxies compared to the Erb et al. study, and also an evolution of the fundamental metallicity relation (FMR) compared to the local relation.

A major component of the Earth's radiation budget is the albedo, the amount of sunlight that the Earth reflects back to space and which never enter its energy budget. Traditionally the Earth's reflectance has been assumed to be roughly constant, but large decadal variability, not reproduced by current climate models, have been reported lately from a variety of sources. The reported albedo variability is much larger than the solar irradiance variability from maximum to minimum of solar activity, and thus has a larger potential to change the Earth’s radiation budget. The Earthshine project is a dedicated project aiming to measure the earth's albedo using the sunlight reflected from the bright and dark side of the Moon using small telescopes. Here, I will discuss the history of the Earthshine project, and its contributions to climate and exoplanet sciences.

The Local Universe provides an excellent high-resolution laboratory for studying the detailed processes of star formation and galaxy evolution. In this seminar, I will present some highlights from multiwavelength star formation studies of nearby HI-selected galaxies as well as our latest results on galaxies in transition. I will show that: (i) selecting galaxies via their HI content is a good way of selecting a large variety of star-forming galaxies regardless of size/stellar luminosity; (ii) the upper mass end of the stellar IMF may not be uniform; (iii) nearby post-starburst galaxies occupy the low-mass end of the green valley and represent a population of galaxies which are quickly going from the blue cloud to the red sequence; and (iv) unlike strong gravitational interactions, ram pressure does not strongly induce star formation. In addition, I will describe the current progress of the ASKAP project.

Low-mass stars form from the gravitational collapse of dense molecular cloud cores. The so-called Class 0 Young Stellar Objects (YSOs), mostly observed from cm to mid-infrared wavelengths, are believed to be the youngest accreting protostars: they are composed of the first embryo of star deeply embedded within an infalling envelope of cold gas and dust. The Class 0 phase is also the main accretion phase, and while accretion onto the central star continues in the Class I and Class II phases, it is by the end of the Class 0 phase that the disk and multiple systems are expected to be formed around the central young star. The initial conditions for the formation and subsequent evolution of both the young star(s) and circumstellar disk(s) are determined during this embedded stage, therefore studying the youngest YSOs during their embedded phase is crucial to establish a comprehensive scenario for the formation of solar-type stars.

I will present our current understanding of the earliest phases of star formation, with an emphasis on theoretical and observational scenarios developed in the past decade to describe the formation of multiple systems and protostellar disks.

I will then show the first results of an observational effort dedicated to solve the angular momentum in low-mass star formation:

the CALYPSO survey, conducted with the IRAM Plateau de Bure interferometer between 2010 and 2013.

I will show how these unprecedented observations allow us to propose a very dynamical scenario for the formation of both circumstellar disks and multiple systems, but also to make progress on our understanding of chemistry processes and jet launching mechanisms during the Class 0 phase.

The quest for planets located in habitable zones, and, ultimately, life on extrasolar planets has already started. The origin of life in most extreme environments and the conditions for its evolution on Earth may be useful guides for our search of extraterrestrial Life. The emergence of photosynthesis early in Earths history marked the beginning of fundamental changes in climate and furnishes significant amounts of molecules far from chemical equilibrium into the atmosphere.

I will present linear polarisation spectra of Earthshine obtained with FORS2. The measurements demonstrate that polarimetric spectra of the Earth contain robust information on biosignatures. (Spectro)polarimetry may become key for the imminent search for life on exoplanets with the next generation of giant, ground-based, telescopes.

The Luminosity Function (LF) is an important tool in studying the redshift evolution of galaxy populations. It is, however, dependent on the cosmological model assumed in its computation. Despite the current constraining power of the combined observational results from the Supernovae (SNe) Ia hubble diagram, the Cosmic Microwave Background (CMB) power spectrum, the Baryonic Accoustic Oscillation scale, and the various measurements of the Hubble constant, there is still debate on the cosmology, with some alternative models being able to fit many of these observations simultaneously. After a quick, conceptual introduction to the giant void class of Lemaitre-Tolman-Bondi (LTB) models, their main features and limitations, I will proceed to present the LF computed using data from the Herschel/PACS Evolutionary Probe (PEP) survey, assuming both the standard and two parameterizations of giant void models. I will show that the characteristic density and luminosity of the FIR selected sources is quite robust over a change in the cosmology, over the whole redshift interval, from z~0 to z~3, but also that, at low redshifts, there is a significant difference between the void models faint-end slopes and the one in the standard model.

We performed time-series observations of 12 ACS/WFC3 fields in the Sagittarius low-reddening window in the Galactic bulge, by sampling the region every two weeks for seven consecutive months. The aim of the project is to detect isolated black holes and neutron stars through astrometric microlensing.

I will present in this talk preliminary results based on the reduction of four ACS fields. The composite V,I-band photometric catalog includes about 1 milion stars down to V = 30 mag and a large population of candidate white dwarfs. Proper motions have been measured for the SWEEPS ACS field, a deep observation of which was taken in 2004. The time baseline of eight years allowed us to achieve a proper motion accuracy of better than 0.15 mas/yr at V = 26 mag in both coordinates. The analysis of the proper motions shows that most of the white dwarfs have higher velocities compared to the bulk of bulge stars.