Brightest cluster galaxies: the centre can(not?) hold-Reference-Cited by-同舟云学术

Brightest cluster galaxies: the centre can(not?) hold

Published:2020-10-23 Issue:1 Volume:500 Page:310-318
ISSN:0035-8711
Container-title:Monthly Notices of the Royal Astronomical Society
language:en
Short-container-title:

Author:

De Propris Roberto¹^ORCID,West Michael J²,Andrade-Santos Felipe³,Ragone-Figueroa Cinthia⁴⁵^ORCID,Rasia Elena⁵⁶,Forman William³,Jones Christine³,Kipper Rain⁷,Borgani Stefano⁵⁶⁸⁹,Lambas Diego García⁴,Romashkova Elena A¹⁰,Patra Kishore C¹¹

Affiliation:

1. FINCA, University of Turku, Vesilinnantie 5, Turku FI-21400, Finland

2. Lowell Observatory, 1400 W Mars Hill Rd, Flagstaff, AZ 86001, USA

3. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA

4. IATE, CONICET, Universidad Nacional de Córdoba, Laprida 854, X5000BGR, Córdoba, Argentina

5. INAF, Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131 Trieste, Italy

6. IFPU – Institute for Fundamental Physics of the Universe, Via Beirut 2, I-34014 Trieste, Italy

7. Tartu Observatory, University of Tartu, Observatooriumi 1, 61602 Tõravere, Estonia

8. Dipartimento di Fisica dell’ Universit‘a di Trieste, Sezione di Astronomia, via Tiepolo 11, I-34131 Trieste, Italy

9. INFN – National Institute for Nuclear Physics, Via Valerio 2, I-34127 Trieste, Italy

10. Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA

11. Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA

Abstract

ABSTRACT 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.

Funder

NED

California Institute of Technology

National Aeronautics and Space Administration

National Science Foundation

University of Maryland

Eotvos Lorand University

Los Alamos National Laboratory

Gordon and Betty Moore Foundation

University of Turku

CONICET

European Union