We present the preliminary results of a mid-infrared study of the Brightest Cluster Galaxies (BCGs) of 55424 galaxy clusters. The clusters are taken from the Gaussian Mixture Brightest Cluster Galaxy (GMBCG) catalog based upon SDSS Data Release 7, covering the redshift range of 0.1 < z < 0.55. Of particular interest, we investigate 458 BCGs that have significant detection at 22um according to the Wide-Field Infrared Survey (WISE) passband 4 (W4). We find that the mid-IR emissions of most of them are predominantly from star formation, which is quite contrary to the usual notion that low redshift BCGs are old, passively evolving galaxies (i.e. "red and dead"). We discuss the implications of our results.
American Astronomical Society Meeting Abstracts #227
- Pub Date:
- January 2016