Identifying dynamically young galaxy groups via wide-angle tail galaxies: a case study in the cosmos field at z= 0.53

Scientific paper - Original scientific paper

• Author: Antonija Oklopčić
• Author: Vernesa Smolčić
• Author: S. Giodini
• Author: G. Zamorani
• Author: L. Bîrzan
• Author: E. Schinnerer
• Author: C. L. Carilli
• Author: A. Finoguenov
• Author: S. Lilly
• Author: A. Koekemoer
• Author: N. Z. Scoville
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics; Astronomy and Astrophysics

Abstract (english)

We present an analysis of a wide-angle tail (WAT) radio galaxy located in a galaxy group in the COSMOS field at a redshift of z = 0.53 (hereafter CWAT-02). We find that the host galaxy of CWAT-02 is the brightest galaxy in the group although it does not coincide with the center of mass of the system. Estimating (1) the velocity of CWAT-02, relative to the intra-cluster medium, and (2) the line-of-sight peculiar velocity of CWAT-02’s host galaxy, relative to the average velocity of the group, we find that both values are higher than those expected for a dominant galaxy in a relaxed system. This suggests that CWAT-02’s host group is dynamically young and likely in the process of an ongoing group merger. Our results are consistent with previous findings showing that the presence of a WAT galaxy in a galaxy group or cluster can be used as an indicator of dynamically young non-relaxed systems. Taking the unrelaxed state of CWAT-02’s host group into account, we discuss the impact of radio-active galactic nucleus (AGN) heating from CWAT-02 onto its environment, in the context of the missing baryon problem in galaxy groups. Our analysis strengthens recent results suggesting that radio-AGN heating may be powerful enough to expel baryons from galaxy groups.

• Keywords (english): cosmology: observations; galaxies: active; galaxies: evolution; galaxies: fundamental parameters; radio continuum: galaxies
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Astrophysical Journal
• Numbering: vol. 713, no. 1, pp. 484-490
• p-ISSN: 0004-637X
• e-ISSN: 1538-4357
• DOI: https://doi.org/10.1088/0004-637X/713/1/484
• URN:NBN: urn:nbn:hr:217:739897
• Publication: 2010
• Document URL: http://dx.doi.org/10.1088/0004-637X/713/1/484
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2010 American Astronomical Society. Received 2009 November 6; accepted for publication 2010 February 23; published 2010 March 23. Based on observations with the National Radio Astronomy Observatory, which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
• Created on: 2019-11-01 19:23:01