Year: 2008
Type: article
Abstract: We present a detailed analysis of the intergalactic metal-line absorption systems in the archival HST STIS and FUSE ultraviolet spectra of the low-redshift quasar PKS 1302–102 ( z QSO = 0.2784). We supplement the archive data with CLOUDY ionization models and a survey of galaxies in the quasar field. There are 15 strong Lyα absorbers with column densities N H I > 14. Of these, six are associated with at least C III λ977 absorption [log N(C + + ) > 13]; this implies a redshift density dN C III / dz = 36 -9 +13 (68% confidence limits) for the five detections with rest equivalent width W r > 50 mÅ. Two systems show O VI λλ1031, 1037 absorption in addition to C III [log N(O + 5 ) > 14]. One is a partial Lyman limit system ( log N H I = 17) with associated C III, O VI, and Si III λ1206 absorption. There are three tentative O VI systems that do not have C III detected. For one O VI doublet with both lines detected at 3 σ with W r > 50 mÅ, dN O VI / dz = 7 -4 +9 . We also search for O VI doublets without Lyα absorption but identify none. From CLOUDY modeling, these metal-line systems have metallicities spanning the range –4 ≲ [ M/H ] ≲ − 0.3. The two O VI systems with associated C III absorption cannot be single-phase, collisionally ionized media based on the relative abundances of the metals and kinematic arguments. From the galaxy survey, we discover that the absorption systems are in a diverse set of galactic environments. Each metal-line system has at least one galaxy within 500 km s −1 and 600 h −1 75 kpc with L > 0.1 L * .
Source: The Astrophysical Journal
DOI: 10.1086/528704
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1982354928