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Origins and Galaxy Evolution

One of the major unsolved problems in physics regards the process of star formation in galaxies. Within the standard cosmological paradigm, dark matter and ordinary matter (mostly in the form of hydrogen and helium gas) collapse within growing density fluctuations forming self-gravitating structures called halos. Within galaxy-sized halos the gas will collapse and trigger star formation. However, this simplistic picture is complicated when considering the many, highly non-linear mechanisms that can play a role in shaping the star formation history of galaxies. The importance of intrinsic and environmental processes in controlling star formation in galaxies is an open question that has kept astrophysicists busy for decades.

Our research focuses on exploring the formation of galaxies both from a theoretical and an observational side. The goal is to determine the importance of processes such as feedback from supernovae or from Active Galactic Nuclei (AGN) to quench (or stimulate) star formation. We also study the evolution of dust and the complex astrochemistry present in star forming regions. Our theoretical work involves both phenomenological modelling as well as ab initio chemodynamical simulations. We also work on hydrodynamical simulations of the interaction between the jet from an AGN and the interstellar medium. The most detailed simulations are run in Legion, UCL's new 2,560-core supercomputer.

On the observational side we cover the full electromagnetic spectrum, from Gamma Rays to radio astronomy. MSSL is the lead UK institute for the ultraviolet/optical telescope on Swift. Swift is a NASA satellite dedicated to the capture of Gamma Ray Bursts. We are also the lead institute for the optical/ultraviolet telescope onboard the European Space Agency's XMM-Newton X-ray observatory. P&A are involved in several submillimeter surveys with HARP and SCUBA2 on the JCMT.

Regarding future missions, we are involved in two major missions from the European Space Agency: Herschel (a far infrared telescope larger in aperture than the Hubble Space Telescope), which is due for launch early in 2009 and Gaia (a mission that will map up to a billion stars in our Galaxy). We are also active users of optical, infrared, submillimeter and radio ground-based telescopes. Finally, we are involved in the successor to the Hubble Space Telescope: The James Webb Space Telescope, a 6.5 metre telescope that will revolutionise our understanding of galaxy formation in the coming decade.

Our research is carried out both at MSSL and the department of Physics & Astronomy (P&A), keeping close links and active collaborations. The main emphasis at MSSL is on galaxy formation and evolution studies and X-ray astronomy, whereas P&A focuses on astrochemical studies of galactic and extra-galactic star forming regions and circumstellar environments.

PhD Projects on offer

"The Chemical Composition of Star Forming Regions Near and Far"

Serena Viti (P&A) & Ignacio Ferreras (MSSL)

This project deals with the investigation of the chemical composition of massive star forming regions in low and high redshift galaxies. Massive stars are essential in defining the structure and evolution of their host galaxies: the injection of large amounts of energy and mass into the Interstellar Medium plays an important role in the distribution of warm gas and hence in galaxy evolution.

The student will couple two existing computer models - a chemical enrichment and galaxy formation model with a star formation chemical model - with the aim of 'constructing' the star formation history of a wide range of galaxies, from starburst to dwarfs, from low to high redshift.

This is an extremely topical subject as the cloud-scale observations of molecular clouds and star-forming sites in external galaxies is one of the major goals of ALMA.

For more information, contact: sv AT star.ucl.ac.uk (replace 'AT' by @)

"Chemodynamical Modelling of Galactic Discs"

Daisuke Kawata (MSSL) & Jeremy Yates (P&A)

This project aims to construct the most sophisticated chemodynamical model of galactic discs. Stars form from the interstellar medium (ISM) and there are both chemical and energetic feedback from stars to the ISM due to supernovae as well as mass loss from evolved stars.  It is still unknown how the ISM and stars are affecting each other in the galactic disc. This is a very active area of reserch in astrophysics.

The student will add more sophisticated models of the ISM physics, star formation and feedback to the existing particle-based galactic chemodynamics simulation code, GCD+. The new improved code will be tested and calibrated by comparing high-resolution simulations of rotating discs with the latest multi-wavelength observations of the ISM and stars in discs of galaxies with different masses.  The new code will be a unique tool to study the evolution of disc galaxies.

For more information, contact: d.kawata AT ucl.ac.uk (replace 'AT' by @)

Recent Papers of interest

  • Timescales for Low-Mass Star Formation in Extragalactic Environments: Implications for the Stellar IMF. Banerji, M., Viti, S., Williams, D. A. & Rawlings, J. M. C. 2008, arXiv:0810.3662
  • Molecular tracers of high-mass star formation in external galaxies. Viti, S., Williams, D. A., Rawlings, J. M. C. 2008 ApJ, 676, 978
  • Strangulation in galaxy groups. Kawata, D., Mulchaey, J. S. 2008 ApJ, 672, L103
  • The star formation history of the Universe as revealed by deep radio observations. Seymour, N.; Dwelly, T.; Moss, D.; McHardy, I.; Zoghbi, A.; Rieke, G.; Page, M.; Hopkins, A.; Loaring, N. 2008 MNRAS, 386, 1695
  • Unveiling dark haloes in lensing galaxies. Ferreras, I., Saha, P., Burles, S. 2008 MNRAS, 383, 857
  • Molecular signature of star formation at high redshifts. Viti, S. & Lintott, C. J. 2008, Ap&SS, 313, 327
  • Decoding the spectra of SDSS early-type galaxies: New indicators of age and recent star formation. Rogers, B., Ferreras, I., Lahav, O., Bernardi, M., Kaviraj, S., Yi, S. K. 2007 MNRAS, 382, 750





This page last modified 14 November, 2008 by Ignacio Ferreras