info:eu-repo/semantics/article
Brightest cluster galaxies: The centre can(not?) hold
Fecha
2021-01Registro en:
de Propris, Roberto; West, Michael J.; Andrade-Santos, Felipe; Ragone Figueroa, Cinthia Judith; Rasia, Elena; et al.; Brightest cluster galaxies: The centre can(not?) hold; Wiley Blackwell Publishing, Inc; Monthly Notices of the Royal Astronomical Society; 500; 1; 1-2021; 310-318
0035-8711
1365-2966
CONICET Digital
CONICET
Autor
de Propris, Roberto
West, Michael J.
Andrade-Santos, Felipe
Ragone Figueroa, Cinthia Judith
Rasia, Elena
Forman, William
Jones, Christine
Kipper, Rain
Borgani, Stefano
Garcia Lambas, Diego Rodolfo
Romashkova, Elena A.
Patra, Kishore C.
Resumen
We explore the persistence of the alignment of brightest cluster galaxies (BCGs) with their local environment. We find that a significant fraction of BCGs do not coincide with the centroid of the X-ray gas distribution and/or show peculiar velocities (they are not at rest with respect to the cluster mean). Despite this, we find that BCGs are generally aligned with the cluster mass distribution even when they have significant offsets from the X-ray centre and significant peculiar velocities. The large offsets are not consistent with simple theoretical models. To account for these observations BCGs must undergo mergers preferentially along their major axis, the main infall direction. Such BCGs may be oscillating within the cluster potential after having been displaced by mergers or collisions, or the dark matter halo itself may not yet be relaxed.