Dynamics of Abell 3266 - I. An optical view of a complex merging cluster
Abstract
We present spectroscopy of 880 galaxies within a 2° field around the massive, merging cluster Abell 3266. This sample, which includes 704 new measurements, was combined with the existing redshifts measurements to generate a sample of over 1300 spectroscopic redshifts; the largest spectroscopic sample in the vicinity of A3266 to date. We define a cluster sub-sample of 790 redshifts that lie within a velocity range of 14 000 to 22 000 km s-1 and within 1° of the cluster centre. A detailed structural analysis finds A3266 to have a complex dynamical structure containing six groups and filaments to the north of the cluster as well as a cluster core that can be decomposed into two components split along a northeast-southwest axis, consistent with previous X-ray observations. The mean redshift of the cluster core is found to be 0.0594 ± 0.0005 and the core velocity dispersion is given as 1462^{+99}_{-99} km s-1. The overall velocity dispersion and redshift of the entire cluster and related structures are 1337^{+67}_{-67} km s-1 and 0.0596 ± 0.0002, respectively, though the high velocity dispersion does not represent virialized motions but rather is due to relative motions of the cluster components. We posit A3266 is seen following a merger along the northeast-southwest axis; however, the rich substructure in the rest of the cluster suggests that the dynamical history is more complex than just a simple merger with a range of continuous dynamical interactions taking place. It is thus likely that turbulence in A3266 is very high, even for a merging cluster.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2017
- DOI:
- 10.1093/mnras/stx582
- arXiv:
- arXiv:1703.02616
- Bibcode:
- 2017MNRAS.468.2645D
- Keywords:
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- galaxies: clusters: general;
- galaxies: clusters: individual: A3266;
- galaxies: distances and redshifts;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 11 pages, 9 figures, 3 tables, accepted for publication in MNRAS