Molecular hydrogen in absorption at high redshifts. Science cases for CUBES

Abstract

Absorption lines from molecular hydrogen (${\mathrm{H}}_2$) in the spectra of background sources are a powerful probe of the physical conditions in intervening cold neutral medium. At high redshift, $z>2$, ${\mathrm{H}}_2$ 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 ${\mathrm{H}}_2$ observations at high-z: probing the physical conditions in the cold phase of regular galaxies and outflowing gas from active galactic nucleus.

16 pages, 5 figures, accepted for publication in Experimental Astronomy, CUBES Special Issue

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Cited by in corpus (2)

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