An Objective Multicolor Method for the Characterization of Low-Resolution X-Ray Spectra
Abstract
We describe a new technique for the characterization of low-resolution X-ray spectra, based on generalized colors defined by means of a principal component analysis. Application of the method to a sample of optically and radio-selected Einstein Observatory X-ray sources yields groups that are dominated either by stars or by extragalactic sources. The method thereby provides an immediate interpretation in terms of differences in the physics of the emission processes dominating the objects studied. The principal advantages of the method are that it provides an objective means of classifying source spectra and that it provides an objective means of obtaining the minimal set of spectral classification parameters. Though the method does not significantly improve results obtained with previously employed techniques when applied to Einstein data, its objective operation should prove powerful in aiding source classification in the more recent medium spectral resolution X-ray surveys based on the ROSAT and ASCA mission.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1995
- DOI:
- Bibcode:
- 1995ApJ...446..108C
- Keywords:
-
- X-RAYS: GALAXIES;
- X-RAYS: STARS