Cookies

We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.


Durham Research Online
You are in:

The cluster-scale environment of PKS 2155-304.

Farina, E. and Fumagalli, M. and Decarli, R. and Fanidakis, N. (2016) 'The cluster-scale environment of PKS 2155-304.', Monthly notices of the Royal Astronomical Society., 455 (1). pp. 618-625.

Abstract

PKS 2155−304 is one of the brightest extragalactic source in the X-ray and EUV bands, and is a prototype for the BL Lac class of objects. In this paper, we investigate the large-scale environment of this source using new multi-object as well as long-slit spectroscopy, together with archival spectra and optical images. We find clear evidence of a modest overdensity of galaxies at z = 0.116 10 ± 0.000 06, consistent with previous determinations of the BL Lac redshift. The galaxy group has a radial velocity dispersion of 250+80−40 km s−1 and a virial radius of 0.22 Mpc, yielding a role-of-thumb estimate of the virial mass of Mvir ∼ 1.5 × 1013 M⊙, i.e. one order of magnitude less than that observed in similar objects. This result hints towards a relatively wide diversity in the environmental properties of BL Lac objects.

Item Type:Article
Keywords:BL Lacertae objects: individual: PKS 2155−304, Galaxies: groups: general.
Full text:(VoR) Version of Record
Download PDF
(1777Kb)
Status:Peer-reviewed
Publisher Web site:http://dx.doi.org/10.1093/mnras/stv2277
Publisher statement:This article has been accepted for publication in Monthly notices of the Royal Astronomical Society. ©: 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Date accepted:28 September 2015
Date deposited:23 November 2015
Date of first online publication:05 November 2015
Date first made open access:No date available

Save or Share this output

Export:
Export
Look up in GoogleScholar