Research

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The ESO Fellows carry out independent astronomical research with the ultimate goal to understand how planets, stars and galaxies in the Universe form and evolve. 

Below is a description of the main research carried out by each Fellow divided according to below listed main scientific areas at ESO.

Planets and Star Formation

Topics covered in this research area

  • Detection and characterisation of extrasolar planets
  • Observational methods to study the earliest stages of star formation
  • The circumstellar environment of high and low mass stars
  • Star formation at the Galactic Centre

Adam Ginsburg: I work on the formation of massive stars and massive star clusters. I use millimeter continuum and heterodyne instruments to look at cold dust and molecules in proto-cluster environments to examine the processes governing their collapse, especially turbulence in the interstellar medium. I am leading a large survey of the Galactic Center using SHFI-1 on the APEX telescope in which we are measuring the temperature of all of the gas in our Galaxy's center. My primary tool is the Formaldehyde molecule, which I have observed at centimeter and millimeter wavelengths in order to determine local gas temperature and density. I am also interested in outflows from forming stars, which I observe in the near-infrared primarily using H2 and FeII lines.

Izaskun Jimenez-Serra: My main interest focuses on understanding the physical processes involved in the formation of the most massive stars in our Galaxy. For this research, I use molecules, and their chemistry, as tools to probe the physics in dense molecular clouds. My studies cover from the large-scale structure and gas dynamics in Infrared-Dark Clouds (the precursors of massive stars) to the internal physical structure and chemistry in Hot Molecular Cores (one of the last stages in the formation of massive stars). I have recently become interested in the chemistry of pre-biotic molecules such as glycine (the simplest amino acid), and the possibility to detect this complex organic molecule in young Solar-type systems with the new ESO facility, the Atacama Large Millimeter Array (ALMA).

Ke Wang: My research focuses on high-mass star formation at the earliest stages. This process involves multiple scales, from individual "star formation seeds" of ~0.01 pc up to Galactic scale filaments of the order 100 pc. Using submm/mm/cm interferometers including ALMA, JVLA, SMA, and CARMA, I study at high resolution the gravitational collapse and hierarchical fragmentation of natal clouds, known as infrared dark clouds (IRDCs). I lead a project under the DFG priority program "Physics of the Interstellar Medium" to systematically characterize Galactic scale molecular filaments, enabled by large observing programmes of APEX and Herschel.

Stellar Structure and Evolution

Topics covered in this research area

  • Stellar evolution, especially the late stages, for example:
    • Mass loss
    • Planetary nebulae
    • Supernovae
  • Stellar surface abundances
  • Stellar surface structures
  • Stellar pulsations
  • Stellar magnetic fields and magnetic activity
  • Low mass stars
  • Black holes and neutron stars

These research topics are covered using observations from X-rays to Infrared, and with many different techniques, e.g., high resolution optical/IR spectroscopy, optical interferometry and polarimetry.

 

Stellar Populations

Topics covered in this research area

Subject in this research area aim at understanding the stellar content of nearby star clusters and galaxies with the goal of understanding their formation and evolution history.

  • Resolved and unresolved star cluster (formation, stellar content, destruction)
  • Resolved stellar populations in the Local Group and nearby galaxies
  • Dwarf galaxies (stellar content and dynamics)
  • Nearby galaxies (integrated light, dynamics, central objects)

Evolution of Galaxies and the ISM

Topics covered in this research area

Subject in this research area aim at understanding the formation and evolution of galaxies from low to high redshift, their mass assembly and enrichment histories, as well as the connection to active galactic nuclei.

  • Evolution of the interstellar medium in galaxies
  • Evolution of galaxy structure and dynamics
  • High-redshift galaxies and galaxy clusters
  • Co-evolution of black holes and galaxies

Matthieu Bethermin: I work on the formation and evolution of galaxies. I am especially interested by the populations of dust star-forming galaxies at high-redshift. These galaxies form the majority of stars at high redshifts and emits mainly in the far-infrared and the sub-millimeter domain. I develop statistical models describing the evolution of these galaxies and their contribution to the cosmic infrared background, the relic emission of all galaxies across cosmic time. I also study the clustering of these galaxies using deep surveys (Spitzer, Herschel) and background fluctuations (Herschel, Planck) to put constraints on the type of dark matter halos hosting them. In addition, I perform measurements of average dust and gas content using a statistical technique called stacking to better understand  why the star formation in high redshift galaxies is so intense.

Timothy A. Davis: My work focuses on the ISM of other galaxies, both in "red and NOT dead" early-type galaxies, and in extreme environments such as the starbursts found in merging galaxies. I work on understanding the origin (accretion, mergers, stellar mass loss) and fate of the ISM (star formation, quenching), and its chemical evolution. I have lead the ATLAS3D CARMA molecular gas imaging survey, and the followups of this survey and the VIXENS project. Furthermore I lead studies which use molecular gas as a kinematic tracer, both of galactic potentials (e.g. for the Tully-Fisher relation) and on smaller scales as a technique for measuring black-hole masses.

Ivan Oteo: I am studying the evolution of star-forming galaxies with cosmic time by using a multi-wavelength approach. The aim is characterizing how the main physical properties of galaxies (dust attenuation, star-formation rate, stellar mass) are changing from the early to the local Universe. To do that, different samples of star-forming galaxies are used, comparing the results obtained with each of them. I am also interested in the properties of high-redshift IR-luminous galaxies, mainly their molecular gas content, and the study of extreme systems at high-redshift.

Tayyaba Zafar: My research focuses on the dust, gas and metals in the ISM of Gamma-ray burst (GRB) afterglows and intervening absorbers towards quasars sightlines. From the spectroscopic and photometric data, I measure extinction in these objects by determining the amount of light lost. For better estimates, I use X-ray, optical and near-infrared data to build spectral energy distributions. I also estimate from the absorption line properties that how much metals are present in the environment and out of that how much fraction is present in dust and gas phase. All these studies provide details of the ISM of these environments. Furthermore, I try to detect faint absorbers along the line of sight of quasar. This provides galaxy properties of these objects e.g., star formation, morphology etc.

Cosmology and the Early Universe

Topics covered in this research area

Subjects in this research area aim at understanding the dark contents of the Universe (Dark Matter and Dark Energy) with the goal of understanding its expansion history since the Big Bang.

  • Type Ia supernovae as probes of Dark Energy
  • Type II supernovae as extragalactic distance indicators (Hubble constant)
  • X-ray clusters and the Sunyaev-Zel'dovich effect
  • Weak lensing and the large-scale distribution of Dark Matter
  • Cosmology with the European Extremeley Large Telescope (E-ELT)

Kate Maguire: My research focuses on improving the use of Type Ia supernovae (SNe Ia) as cosmological probes. I am interested in using observational techniques to constrain their progenitor systems and explosion mechanisms, as well as the diversity of thermonuclear SNe. I lead a project as part of the PESSTO collaboration to explore the extremes of the SN Ia population, particularly SNe in remote locations far from the centre of their host galaxies. I also work on linking the detection of circumstellar material to observed SN Ia properties, with the aim of distinguishing between progenitor scenarios. In addition, I lead observational studies to constrain SN Ia explosion mechanisms through modelling of their newly synthesised material, which is visible in late-time optical and near-infrared spectra.