Yamada, TomuKoyama, YNakata, FKajisawa, MTanaka, IchiKodama, TOkamura, SatoshiDe Propris, Roberto2015-12-132015-12-130004-637Xhttp://hdl.handle.net/1885/75183We have obtained a new high-resolution K′-band image of the central region of the rich X-ray cluster RX J0848.9+4452 at z = 1.26. We found that the brightest cluster galaxy (BCG) in the cluster is clearly separated into two distinct objects. Whereas theKeywords: Galaxies: elliptical and lenticular, cD; Galaxies: evolution; Galaxies: formationWitnessing the Hierarchical Assembly of the Brightest Cluster Galaxy in a Cluster at z = 1.26200210.1086/3444002015-12-11