Intrinsic Absorption in the HST Archive I: Search for Time Variable Systems
Abstract
We present a search for time-variable narrow absorption lines (NALs) in HST quasar spectra. NALs which appear in the spectra of quasars can be very powerful probes of physical conditions of a variety of structures. The primary signatures distinguishing intrinsic NALs from intervening NALs are partial coverage of the background source and time variability. Using low-dispersion, multi-epoch observations of quasars in the HST archive, we devised and implemented a method of selecting time-variable absorption lines. Using multi-epoch data for 72 quasars that span a large range of redshift and luminosity, we performed this selection and compiled a catalog of identified lines. We present 9 time-variable, and therefore intrinsic, systems detected in 8 of the quasars. We put forward several tests to investigate the cause of variability (ionization changes or motion of gas). This contribution is presented as a companion to another contribution in which intrinsic systems are identified using partial coverage.
This work was supported by the Space Telescope Summer Student Program, SURAP at the Wyoming Infrared Observatory, and NASA through grant numbers HST-AR-10296 and NAG5-10817.- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AAS...209.7209G