Naslov
Identifying Dynamically Young Galaxy Groups Via Wide-angle Tail Galaxies : A Case Study in the COSMOS Field at z = 0.53

Autori
Oklopčić, Antonija ; Smolčić, Vernesa ; Giodini, S. ; Zamorani, G. ; Bîrzan, L. ; Schinnerer, E. ; Carilli, C.L. ; Finoguenov, A. ; Lilly, S. ; Koekemoer, A. ; Scoville, N.Z.

Izvornik
The Astrophysical journal (0004-637X) 713 (2010), 1; 484-490

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
cosmology: observations; galaxies: active; galaxies: evolution; galaxies: fundamental parameters; radio continuum: galaxies

Sažetak
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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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