The X-ray properties of optically selected clusters of galaxies
Abstract
We present the results of Chandra and Suzaku X-ray observations of nine moderate-redshift (0.16 < z < 0.42) clusters discovered via the Red-sequence Cluster Survey (RCS). Surface brightness profiles are fitted to β-models, gas masses are determined, integrated spectra are extracted within R2500, and X-ray temperatures and luminosities are inferred. The LX-TX relationship expected from self-similar evolution is tested by comparing this sample to our previous X-ray investigation of nine high-redshift (0.6 < z < 1.0) optically selected clusters. We find that optically selected clusters are systematically less luminous than X-ray selected clusters of similar X-ray temperature at both moderate and high z. We are unable to constrain evolution in the LX-TX relation with these data, but find it consistent with no evolution, within relatively large uncertainties. To investigate selection effects, we compare the X-ray properties of our sample to those of clusters in the representative X-ray selected sample, also determined within R2500. We find that while RCS cluster X-ray properties span the entire range of those of massive clusters selected by other methods, their average X-ray properties are most similar to those of dynamically disturbed X-ray selected clusters. This similarity suggests that the true cluster distribution might contain a higher fraction of disturbed objects than are typically detected in X-ray selected surveys.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2013
- DOI:
- 10.1093/mnras/stt348
- arXiv:
- arXiv:1303.1819
- Bibcode:
- 2013MNRAS.431.2542H
- Keywords:
-
- galaxies: clusters: general;
- cosmology: observations;
- large-scale structure of Universe;
- X-rays: galaxies: clusters;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 13 pages, 5 figures