Molecular hydrogen in absorption at high redshifts

S. A. Balashev , P. Noterdaeme (1)

1 IAP - Institut d'Astrophysique de Paris

Absorption lines from molecular hydrogen (H₂) in the spectra of background sources are a powerful probe of the physical conditions in intervening cold neutral medium. At high redshift, z >2 , H₂ lines are conveniently shifted in the optical domain, allowing the use of ground-based telescopes to perform high-resolution spectroscopy, which is essential for a proper analysis of the cold gas. We describe recent observational progress, based on the development of efficient pre-selection techniques in low-resolution spectroscopic surveys such as the Sloan Digital Sky Survey (SDSS). The next generation of spectrographs with high blue-throughput, such as CUBES, will certainly significantly boost the efficiency and outcome of follow-up observations. In this paper, we discuss high priority science cases for CUBES, building on recent H₂ observations at high-z: probing the physical conditions in the cold phase of regular galaxies and outflowing gas from active galactic nucleus.

Mots clés: Molecular hydrogen; Quasar absorption lines; Active galactic nuclei

Domaines: Planète et Univers [physics]

S. A. Balashev, P. Noterdaeme. Molecular hydrogen in absorption at high redshifts. Experimental Astronomy, 2022, ⟨10.1007/s10686-022-09843-y⟩. ⟨insu-03748289⟩