Speaker
Description
Combining QSO absorption-line spectroscopy with IFU emission-line observations provides a powerful probe of the multiphase gaseous environments of galaxies. We will discuss systems for which these observations have illuminated the co-evolution of galaxies and the circumgalactic medium and the promise of this approach in the era of 30m-class telescopes. We will then focus on the subset of QSO sightlines that reveal H$_{2}$-bearing DLAs, highlighting the detection of such a system at $z = 0.576$ towards J0111-0316. This system, observed with HST-COS as part of the Cosmic Ultraviolet Baryon Survey, has ${\rm log}\,(N({\rm H}_{2})) = 17$ and ${\rm log}\,(f({\rm H}_{2})) = -3.1$, with multiple velocity components resolved in both the atomic and molecular phases. We will discuss the kinematics, chemical properties, and ionization state of the system, and use the excitation state of the molecular hydrogen to probe the physical conditions in the cloud cores. Extensive ground-based spectroscopy from the Magellan Telescopes provides information about the galaxy population local to the DLA, and we will explore possible origin scenarios for the system. Pairing these and similar observations with IFU emission-line spectroscopy will allow the relationship between molecular cloud cores and their diffuse gaseous environments to be studied in a spatially-resolved sense.
| Wish list question? | 3. At high redshift, how do HI emission-line and absorption-line observations relate to optical absorption-line and molecular emission-line measurements of cosmic gas reservoirs? |
|---|
