DLAs are the primary reservoirs of neutral gas available for star formation at high redshift. However, DLAs are metal poor and lack molecular gas. In this thesis, I present a study of an extraordinary case of a z=2.06 sub-DLA towards the quasar J2123−0050, which is characterized by a metallicity that approaches solar, and a high H2 molecular fraction (log f(H2) = −2.54). Furthermore, this SDLA harbors HD molecules, only the third such detection at high redshift, and with the highest (HD/2H2) fraction of -2.75. To understand these observations, I study the effects of dust depletion and photoionization on the interpretation of raw abundance measurements. I find that the magnitude of photoionization and dust depletion effects has a profound impact on the interpretation of this SDLA. The calculated corrections lower the elemental and molecular abundances suggesting that the ISM in the SDLA towards J2123−0050 exhibits properties similar to the
gas in the local sightlines.
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/1711 |
| Date | 01 September 2009 |
| Creators | Milutinovic, Nikola |
| Contributors | Ellison, Sara L. |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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