Exploring Damped Lyα System Host Galaxies Using Gamma-Ray Bursts

Toy, Vicki L.; Cucchiara, Antonino; Veilleux, Sylvain; Fumagalli, Michele; Rafelski, Marc; Rahmati, Alireza; Cenko, S. Bradley; Capone, John I.; Pasham, Dheeraj R.

Abstract

We present a sample of 45 Damped Lyman-α system (DLA, \nhi\ ≥2×1020cm−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∼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 SED modeling. We find that DLA counterpart SFRs are not correlated with either redshift or HI column density. Thanks to the combination of \hst\ 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∼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 LBG 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.

Citation

Toy, V. L., Cucchiara, A., Veilleux, S., Fumagalli, M., Rafelski, M., Rahmati, A., …Pasham, D. R. (2016). Exploring Damped Lyα System Host Galaxies Using Gamma-Ray Bursts. Astrophysical Journal, 832(2), Article 175. https://doi.org/10.3847/0004-637x/832/2/175

• Journal Article Type: Article
• Acceptance Date: Sep 15, 2016
• Online Publication Date: Nov 30, 2016
• Publication Date: Dec 1, 2016
• Deposit Date: Dec 17, 2016
• Publicly Available Date: Dec 19, 2016
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 832
• Issue: 2
• Article Number: 175
• DOI: https://doi.org/10.3847/0004-637x/832/2/175
• Public URL: https://durham-repository.worktribe.com/output/1397249