The X-Ray Properties of Moderate-Redshift Galaxy Groups Selected by Association with Gravitational Lenses
Abstract
We present results from a systematic investigation of the X-ray properties of a sample of moderate-redshift (0.3 < z < 0.6) galaxy groups. These groups were selected not by traditional X-ray or optical search methods, but rather by an association, either physical or along the line of sight, with a strong gravitational lens. We calculate the properties of seven galaxy groups in the fields of six lens systems. Diffuse X-ray emission from the intragroup medium is detected in four of the groups. All of the detected groups have X-ray luminosities greater than 1042 h-2 ergs s-1 and lie on the LX-σv relations defined by local groups and clusters. The upper limits for the nondetections are also consistent with the local LX-σv relationships. Although the sample size is small and deeper optical and X-ray data are needed, these results suggest that lens-selected groups are similar to X-ray-selected samples and thus are more massive than the typical poor-group environments of local galaxies.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2008
- DOI:
- 10.1086/588087
- arXiv:
- arXiv:0711.2066
- Bibcode:
- 2008ApJ...681.1017F
- Keywords:
-
- galaxies: clusters: general;
- gravitational lensing;
- X-rays: galaxies: clusters;
- Astrophysics
- E-Print:
- Accepted for publication in ApJ (July 10, 2008 issue). New smoothing technique reveals that one system (B2108) has a multiple-peak brightness distribution. Changed discussion and figures accordingly. Corrected some values in Table 2