| Type |
Conference Paper |
| Names |
Blair D. Savage, A. Narayanan, B. Wakker, C. Danforth, C. Froning, J. Green, B. Keeney, K. Sembach, M. Shull, J. Stocke, Y. Yao |
| Proceedings Title |
Bulletin of the American Astronomical Society |
| Conference Name |
American Astronomical Society, AAS Meeting #215, #464.24 |
| Volume |
42 |
| Pages |
502 |
| Date |
January 1, 2010 |
| URL |
http://adsabs.harvard.edu/abs/2010AAS...21546424S |
| Library Catalog |
NASA ADS |
| Abstract |
Signal-to-noise > 35 observations with the COS of the QSO PKS
0405-123 (z em = 0.5726) at a resolution of 15 to 20 km/s from 1150 to
1780 A are analyzed to study the physical conditions in the prominent O
VI absorption systems at z = 0. 16710, 0.18292, 0.36156, 0.36332 and
0.49501. These systems have previously been studied in STIS and FUSE
spectra with S/N 10 to 15. The system at z = 0.16710 is a Lyman limit
system with logN(HI) = 16.45 +/-0.05 (Prochaska et al. 2004). Chen and
Mulchaey (2009) have found Galaxies with impact parameters of 81, 165
and 77 kpc associated with the z = 0.16710, O.36156, and 0.49501
absorbers. No galaxies with impact parameters < 1 Mpc have been found
associated with the other two absorbers. The high S/N of the
observations allows the measurement of important ions not previously
detected and permits a careful evaluation of the kinematical
relationships among the detected ions. The observations are being used
to determine the origin of the ionization of O VI in simple and complex
absorption systems. The high S/N allows a search for broad Ly alpha
possibly associated with O VI if it is collisonally ionized at T
3x105 K. The multi-phase system at z = 0.16710 may be tracing
a high velocity cloud in the halo of the associated galaxy. The UV
properties of this absorber are similar to that for the high velocity
clouds in the Milky Way halo where O VI is likely produced in interface
regions between hot halo gas with T >1x106 K and the
cooler gas of the HVC. The observations show that COS is extremely well
suited for studies at low redshift of the surroundings of galaxies and
their connection to the cosmic web. |