Cosmology Seminar: Lise Christensen

Lise Christensen is a professor at the DARK Cosmology Center, University of Copenhagen

The nature of absorption selected galaxies

At the discovery of damped-Lyman alpha absorbers (DLAs) in quasar
spectra more than three decades ago, their nature and association with
galaxies was a mystery. DLAs are unique probes of neutral gas through
the universe, and can be used to trace metallicities out to redshifts
beyond z=5.
 
With new, more sensitive spectrographs we have now begun to find the
galaxies that are responsible for the absorption line systems. We have
found that DLAs obey a relation between metallicities and stellar
masses of the host galaxies, just as luminosity selected galaxy
samples show a mass-metallicity relation.
 
Now that we have found the connection between the neutral gas and the
stellar population in galaxies, the next step is to investigate the
molecular gas in the galaxies to get a comprehensive picture of how
absorption selected galaxies convert their gas into stars. This will
finally allow us to study the nature of low-mass galaxies out to the
highest redshifts.

Organizer

Bridget Falck and Benjamin Racine
Published Feb. 21, 2017 12:26 PM - Last modified Mar. 6, 2017 1:12 PM