We report the serendipitous detection of an H2-bearing damped Lyα absorber at z = 0.576 in the spectrum of the QSO J0111-0316 in the Cosmic Ultraviolet Baryon Survey. Spectroscopic observations from Hubble Space Telescope-COS in the far-ultraviolet reveal a damped absorber with log[N(H i)/cm-2] = 20.1 ± 0.2 and log[N(H2)/cm-2] =18.97-0.06+0.05. The diffuse molecular gas is found in two velocity components separated by Δ ν ≈ 60 km s-1, with >99.9% of the total H2 column density concentrated in one component. At a metallicity of ≈50% of solar, there is evidence for Fe enhancement and dust depletion, with a dust-to-gas ratio κ O ≈ 0.4. A galaxy redshift survey conducted with IMACS and LDSS-3C on Magellan reveals an overdensity of nine galaxies at projected distance d ≤ 600 proper kpc (pkpc) and line-of-sight velocity offset Δ ν g ≤ 300 km s-1 from the absorber. The closest is a massive, early-type galaxy at d = 41 pkpc that contains ≈70% of the total stellar mass identified at d ≤ 310 pkpc of the H2 absorber. The close proximity of the H2-bearing gas to the quiescent galaxy and the Fe-enhanced chemical abundance pattern of the absorber suggest a physical connection, in contrast to a picture in which DLAs are primarily associated with gas-rich dwarfs. This case study illustrates that deep galaxy redshift surveys are needed to gain insight into the diverse environments that host dense and potentially star-forming gas.

Boettcher, E., Chen, H., Zahedy, F., Cooper, T., Johnson, S., Rudie, G., et al. (2021). The Cosmic Ultraviolet Baryon Survey (CUBS). II. Discovery of an H2-bearing DLA in the Vicinity of an Early-type Galaxy at z = 0.576. THE ASTROPHYSICAL JOURNAL, 913(1) [10.3847/1538-4357/abf0a0].

The Cosmic Ultraviolet Baryon Survey (CUBS). II. Discovery of an H2-bearing DLA in the Vicinity of an Early-type Galaxy at z = 0.576

Cantalupo S.;
2021

Abstract

We report the serendipitous detection of an H2-bearing damped Lyα absorber at z = 0.576 in the spectrum of the QSO J0111-0316 in the Cosmic Ultraviolet Baryon Survey. Spectroscopic observations from Hubble Space Telescope-COS in the far-ultraviolet reveal a damped absorber with log[N(H i)/cm-2] = 20.1 ± 0.2 and log[N(H2)/cm-2] =18.97-0.06+0.05. The diffuse molecular gas is found in two velocity components separated by Δ ν ≈ 60 km s-1, with >99.9% of the total H2 column density concentrated in one component. At a metallicity of ≈50% of solar, there is evidence for Fe enhancement and dust depletion, with a dust-to-gas ratio κ O ≈ 0.4. A galaxy redshift survey conducted with IMACS and LDSS-3C on Magellan reveals an overdensity of nine galaxies at projected distance d ≤ 600 proper kpc (pkpc) and line-of-sight velocity offset Δ ν g ≤ 300 km s-1 from the absorber. The closest is a massive, early-type galaxy at d = 41 pkpc that contains ≈70% of the total stellar mass identified at d ≤ 310 pkpc of the H2 absorber. The close proximity of the H2-bearing gas to the quiescent galaxy and the Fe-enhanced chemical abundance pattern of the absorber suggest a physical connection, in contrast to a picture in which DLAs are primarily associated with gas-rich dwarfs. This case study illustrates that deep galaxy redshift surveys are needed to gain insight into the diverse environments that host dense and potentially star-forming gas.
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Boettcher, E., Chen, H., Zahedy, F., Cooper, T., Johnson, S., Rudie, G., et al. (2021). The Cosmic Ultraviolet Baryon Survey (CUBS). II. Discovery of an H2-bearing DLA in the Vicinity of an Early-type Galaxy at z = 0.576. THE ASTROPHYSICAL JOURNAL, 913(1) [10.3847/1538-4357/abf0a0].
Boettcher, E; Chen, H; Zahedy, F; Cooper, T; Johnson, S; Rudie, G; Chen, M; Petitjean, P; Cantalupo, S; Cooksey, K; Faucher-Gigu re, C; Greene, J; Lopez, S; Mulchaey, J; Penton, S; Putman, M; Rafelski, M; Rauch, M; Schaye, J; Simcoe, R; Walth, G
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10281/338849
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