Brightest cluster galaxy

[1] Formation scenarios for BCGs include: The study of accretion populations in BCGs[2] has cast doubt over this theory and astronomers have seen no evidence of cooling flows in radiative cooling clusters.

It has been shown that the orbit decay of cluster galaxies is not effective enough to account for the growth of BCGs.

[6] The merging model is now generally accepted as the most likely one,[7] but recent observations are at odds with some of its predictions.

For example, it has been found that the stellar mass of BCGs was assembled much earlier than the merging model predicts.

The different parametrizations of the light profile of BCG's, as well as the faintness of the diffuse envelope lead to discrepancies in the reported values of the sizes of these objects.

This image from NASA's Hubble Space Telescope shows the galaxy cluster Abell S0740 that is over 450 million light-years away in the direction of the constellation Centaurus. The giant elliptical galaxy ESO 325-G004 looms large at the cluster's center. This BCG is as massive as 100 billion of our suns.
The brightest galaxy in the image is named SDSS J1156+1911, taken by Hubble [ 9 ]