Exploring Damped Ly Alpha System Host Galaxies Using Gamma-Ray Bursts

• Published in: The Astrophysical journal Vol. 832; no. 2; p. 175
• Main Authors: Toy, Vicki L., Cucchiara, Antonino, Veilleux, Sylvain, Fumagalli, Michele, Rafelski, Marc, Rahmati, Alireza, Cenko, S. Bradley, Capone, John I., Pasham, Dheeraj R.
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center The American Astronomical Society 01.12.2016; IOP Publishing
• Subjects: ABUNDANCE; Astronomical models; Astrophysics; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; Computer simulation; COMPUTERIZED SIMULATION; COSMIC GAMMA BURSTS; DENSITY; Depletion; DETECTION; Disks; Dwarf galaxies; EFFICIENCY; ENERGY SPECTRA; Enrichment; FEEDBACK; Galactic evolution; GALAXIES; Gamma ray bursts; Gamma rays; Ground-based observation; Hubble Space Telescope; METALLICITY; PHOTOMETRY; QUASARS; RED SHIFT; SPACE; Space telescopes; Spectral energy distribution; Star & galaxy formation; STAR EVOLUTION; Star formation; STARS; Stars & galaxies; Statistics And Probability; TELESCOPES; UNIVERSE; Galaxies: High-Redshift €“ Galaxies: Ism €“ Galaxies: Star Formation €“ Gamma
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/0004-637X/832/2/175

We present a sample of 45 Damped Ly-Alpha system [DLA; H I-N is greater than or equal to 2 x 10(exp. 20) cm(exp. -2)] counterparts (33 detections, 12 upper limits) which host gamma-ray bursts (GRB-DLAs) in order to investigate star formation and metallicity within galaxies hosting DLAs. Our sample spans z is approx. 2 - 6 and is nearly three times larger than any previously detected DLA counterparts survey based on quasar line-of-sight searches (QSO-DLAs). We report star formation rates (SFRs) from rest-frame UV photometry and spectral energy distribution modeling. We find that DLA counterpart SFRs are not correlated with either redshift or H I column density. Thanks to the combination of Hubble Space Telescope and ground-based observations, we also investigate DLA host star formation efficiency. Our GRB-DLA counterpart sample spans both higher efficiency and low efficiency star formation regions compared to the local Kennicutt-Schmidt relation, local star formation laws, and z is approximately 3 cosmological simulations. We also compare the depletion times of our DLA hosts sample to other objects in the local universe; our sample appears to deviate from the star formation efficiencies measured in local spiral and dwarf galaxies. Furthermore, we find similar efficiencies as local inner disks, SMC, and Lyman-break galaxy outskirts. Finally, our enrichment time measurements show a spread of systems with under- and over-abundance of metals, which may suggest that these systems had episodic star formation and a metal enrichment/depletion as a result of strong stellar feedback and/or metal inflow/outflow.