Discovery of a Damped Lyα Galaxy at z ∼ 3 toward the Quasar SDSS J011852+040644

Joshi, Ravi; Fumagalli, Michele; Srianand, Raghunathan; Noterdaeme, Pasquier; Petitjean, Patrick; Rafelski, Marc; Mackenzie, Ruari; Li, Qiong; Cai, Zheng; Martin, D. Christopher; Zou, Siwei; Wu, Xue-Bing; Jiang, Linhua; Ho, Luis C.

Abstract

We report the detection of the host galaxy of a damped Lyα system (DLA) with log N(H I) [cm−2 ] = 21.0 ± 0.10 at z ≈ 3.0091 toward the background quasar SDSS J011852+040644 using the Palomar Cosmic Web Imager at the Hale (P200) telescope. We detect Lyα emission in the dark core of the DLA trough at a 3.3σ confidence level, with Lyα luminosity of LLyα = (3.8 ± 0.8) × 1042 erg s−1 , corresponding to a star formation rate of 2 Me yr−1 (considering a lower limit on Lyα escape fraction ~a f esc Ly 2%) as typical for Lyman break galaxies at these redshifts. The Lyα emission is blueshifted with respect to the systemic redshift derived from metal absorption lines by 281 ± 43 km s−1 . The associated galaxy is at very small impact parameter of 12 kpc from the background quasar, which is in line with the observed anticorrelation between column density and impact parameter in spectroscopic searches tracing the large-scale environments of DLA host galaxies.

Citation

Joshi, R., Fumagalli, M., Srianand, R., Noterdaeme, P., Petitjean, P., Rafelski, M., …Ho, L. C. (2021). Discovery of a Damped Lyα Galaxy at z ∼ 3 toward the Quasar SDSS J011852+040644. Astrophysical Journal, 908(2), Article 129. https://doi.org/10.3847/1538-4357/abd1d5

• Journal Article Type: Article
• Acceptance Date: Dec 4, 2020
• Online Publication Date: Feb 18, 2021
• Publication Date: 2021-02
• Deposit Date: Jan 7, 2022
• Publicly Available Date: Jan 10, 2022
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 908
• Issue: 2
• Article Number: 129
• DOI: https://doi.org/10.3847/1538-4357/abd1d5