Kinematic unrest of low mass galaxy groups

Show full item record



Gozaliasl , G , Finoguenov , A , Khosroshahi , H G , Laigle , C , Kirkpatrick , C C , Kiiveri , K , Devriendt , J , Dubois , Y & Ahoranta , J 2020 , ' Kinematic unrest of low mass galaxy groups ' , Astronomy & Astrophysics , vol. 635 , A36 .

Title: Kinematic unrest of low mass galaxy groups
Author: Gozaliasl, G.; Finoguenov, A.; Khosroshahi, H. G.; Laigle, C.; Kirkpatrick, C. C.; Kiiveri, K.; Devriendt, J.; Dubois, Y.; Ahoranta, J.
Contributor organization: Department of Physics
Helsinki Institute of Physics
Particle Physics and Astrophysics
Date: 2020-03-03
Language: eng
Number of pages: 8
Belongs to series: Astronomy & Astrophysics
ISSN: 0004-6361
Abstract: In an effort to better understand the formation of galaxy groups, we examine the kinematics of a large sample of spectroscopically confirmed X-ray galaxy groups in the Cosmic Evolution Survey with a high sampling of galaxy group members up to z & x2004;=& x2004;1. We compare our results with predictions from the cosmological hydrodynamical simulation of HORIZON-AGN. Using a phase-space analysis of dynamics of groups with halo masses of M-200c & x2004;similar to & x2004;10(12.6) - 10(14.50)& x2006;M-circle dot, we show that the brightest group galaxies (BGG) in low mass galaxy groups (M-200c & x2004;<& x2004;2 x 10(13)& x2006;M-circle dot) have larger proper motions relative to the group velocity dispersion than high mass groups. The dispersion in the ratio of the BGG proper velocity to the velocity dispersion of the group, sigma(BGG)/sigma(group), is on average 1.48 +/- 0.13 for low mass groups and 1.01 +/- 0.09 for high mass groups. A comparative analysis of the HORIZON-AGN simulation reveals a similar increase in the spread of peculiar velocities of BGGs with decreasing group mass, though consistency in the amplitude, shape, and mode of the BGG peculiar velocity distribution is only achieved for high mass groups. The groups hosting a BGG with a large peculiar velocity are more likely to be offset from the L-x - sigma(v) relation; this is probably because the peculiar motion of the BGG is influenced by the accretion of new members.
Subject: methods
kinematics and dynamics
115 Astronomy, Space science
Peer reviewed: Yes
Rights: unspecified
Usage restriction: openAccess
Self-archived version: publishedVersion

Files in this item

Total number of downloads: Loading...

Files Size Format View
aa36745_19.pdf 1.499Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record