New Constraints On Gas Properties From The Fuv: Oiv + Ovi Absorbers
Abstract
Despite the increasing numbers of O VI absorbers observed, the ionization mechanisms of these systems is still not well understood. Both photo and collisional ionization seem to play roles in the ionization of the gas in these systems. In order to place constraints on the baryon fractions as traced by O VI absorbers, the ionization mechanisms must be well understood. Part of the confusion is due to the lack of adjacent ionization states of ions in existing spectra. We present new observations with the COS spectrograph of several absorbers at z>0.4 that have O II, OIII, OIV, and OVI absorption lines. With these adjacent ionization stages we can much more tightly constrain the physical conditions in the gas. Here, we present voigt profile fits to these lines, as well as the results of photo and collisional ionization modeling.
- Publication:
-
American Astronomical Society Meeting Abstracts #218
- Pub Date:
- May 2011
- Bibcode:
- 2011AAS...21833203M