Probing galaxy formation at high redshift with damped Lyman alpha systems

• Applicant: Professor Dr. Peter Schneider
• Subject Area: Astrophysics and Astronomy
• Term: from 2005 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5448538

• Final Report Year: 2012

Final Report Abstract

One of the few possibilities to study the formation and evolution of galaxies in the early Universe directly is to investigate the properties of damped Lyman α absorbers (DLAs) at high redshift. DLAs produce very strong H I Lyman α absorption in the spectra of quasars and are believed to represent protogalactic structures. The morphology of DLA host systems at redshifts z > 2 it is not well known, however, and the exact role of DLAs in the hierarchical galaxy formation scenario yet needs to be explored. In this project we have studied high-redshift DLAs using quasar absorption spectroscopy based on spectral data obtained with the VLT. We have analyzed in detail the metal abundances in selected DLA systems to search for characteristic abundance patterns and signatures of an enrichment by the first generation of stars in the Universe. The observed enrichment patterns in the DLAs have been compared the yields of theoretical chemical evolution models and the metal-enrichment signatures of Pop II and Pop III stars. Our project has contributed to our understandig of the morphology and chemical evolution of DLA systems in the early Universe and their role as building blocks for present-day galaxies.

Publications

• (2005): The sub-damped Ly α system toward HE 0001-2340: galaxy formation at z ≈ 2. In: A&A 440 (3), S. 819–829
  Richter, P., Ledoux, C., Petitjean, P., & Bergeron, J.
  (See online at https://doi.org/10.1051/0004-6361:20042064)
• (2006): The most metal-poor damped Lyman $\mathsf{\alpha}$ system at z $\mathsf{<3}$: constraints on early nucleosynthesis. In: A&A 451 (1), S. 19–26
  Erni, P., Richter, P., Ledoux, C., & Petitjean, P.
  (See online at https://doi.org/10.1051/0004-6361:20054328)
• (2007): Absorption features of high-redshift galactic winds. In: Mon Not R Astron Soc 381 (2), S. 469–488
  Fangano, A.P.M., Ferrara, A., Richter, P.
  (See online at https://doi.org/10.1111/j.1365-2966.2007.12220.x)
• 2007, PhD Thesis
  Erni, P.
  
• 2007. Signatures of early metal enrichment in Damped-Lyman Alpha systems. Astronomische Nachrichten 328, 637
  Richter, P., Erni, P.
  (See online at https://doi.org/10.1002/asna.200740003)