Initial Results of a Comprehensive Ultrasoft Survey of the Einstein IPC Database: Source List and Confirmation of the Selection Procedure
Abstract
We have carried out a survey of the entire Einstein IPC database (a total of 5934 sources) to select objects with strong components of ultrasoft X-ray emission (i.e., emission below 0.5 keV). The selection criteria are based on ratios of counts within three broad energy bands (i.e., X-ray ``colors''). A total of 516 objects have been selected, with 202 (39%) having been identified through correlations with other databases. Of the currently identified objects, 45% are active galactic nuclei, 28% are stellar objects, 6% are ``normal'' galaxies and galaxy clusters, and the remaining 21% are ``nonstellar'' Galactic objects such as cataclysmic variables, pulsars, and white dwarfs. We present a discussion of the survey selection procedure, the list of selected sources, and discussions of interesting objects from the aforementioned groups. We discuss the remarkable success of our rather ``low resolution'' method of estimating spectral shape and present plans for follow-up studies of the as yet unidentified sources.
- Publication:
-
The Astronomical Journal
- Pub Date:
- June 1998
- DOI:
- 10.1086/300382
- Bibcode:
- 1998AJ....115.2587T
- Keywords:
-
- STARS: BINARIES: CLOSE;
- STARS: PULSARS: GENERAL;
- SURVEYS;
- STARS: WHITE DWARFS;
- X-RAYS