Absorption Troughs of Lyα Emitters in HETDEX

Weiss, Laurel H.; Davis, Dustin; Gebhardt, Karl; Gazagnes, Simon; Mirza Khanlari, Mahan; Mentuch Cooper, Erin; Chisholm, John; Berg, Danielle; Bowman, William P.; Byrohl, Chris; Ciardullo, Robin; Fabricius, Maximilian; Farrow, Daniel; Gronwall, Caryl; Hill, Gary J.; House, Lindsay R.; Jeong, Donghui; Khoraminezhad, Hasti; Kollatschny, Wolfram; Komatsu, Eiichiro; Lujan Niemeyer, Maja; Saito, Shun; Schneider, Donald P.; Zeimann, Gregory R.

Abstract

The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is designed to detect and measure the redshifts of more than 1 million Lyα emitting galaxies (LAEs) 1.88 < z < 3.52. In addition to its cosmological measurements, these data enable studies of Lyα spectral profiles and the underlying radiative transfer. Using the roughly half a million LAEs in the HETDEX Data Release 3, we stack various subsets to obtain the typical Lyα profile for the z ∼ 2-3 epoch and to understand their physical properties. We find clear absorption wings around Lyα emission, which extend ∼2000 km s−1 both redward and blueward of the central line. Using far-UV spectra of nearby (0.002 < z < 0.182) LAEs in the COS Legacy Archive Spectroscopic Survey treasury and optical/near-IR spectra of 2.8 < z < 6.7 LAEs in the Multi Unit Spectroscopic-Wide survey, we observe absorption profiles in both redshift regimes. Dividing the sample by volume density shows that the troughs increase in higher-density regions. This trend suggests that the depth of the absorption is dependent on the local density of objects near the LAE, a geometry that is similar to damped Lyα systems. Simple simulations of Lyα radiative transfer can produce similar troughs due to absorption of light from background sources by H i gas surrounding the LAEs.

Citation

Weiss, L. H., Davis, D., Gebhardt, K., Gazagnes, S., Mirza Khanlari, M., Mentuch Cooper, E., Chisholm, J., Berg, D., Bowman, W. P., Byrohl, C., Ciardullo, R., Fabricius, M., Farrow, D., Gronwall, C., Hill, G. J., House, L. R., Jeong, D., Khoraminezhad, H., Kollatschny, W., Komatsu, E., …Zeimann, G. R. (2024). Absorption Troughs of Lyα Emitters in HETDEX. The Astrophysical journal, 962(2), Article 102. https://doi.org/10.3847/1538-4357/ad1b51

• Journal Article Type: Article
• Acceptance Date: Jan 3, 2024
• Online Publication Date: Feb 12, 2024
• Publication Date: Feb 20, 2024
• Deposit Date: Feb 29, 2024
• Publicly Available Date: Mar 5, 2024
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 962
• Issue: 2
• Article Number: 102
• DOI: https://doi.org/10.3847/1538-4357/ad1b51
• Public URL: https://hull-repository.worktribe.com/output/4567309