File(s) under permanent embargo
Head-tail Galaxies: beacons of high-density regions in clusters
journal contribution
posted on 2023-05-17, 00:32 authored by Mao, MY, Johnston-Hollitt, M, Stevens, JB, Wotherspoon, SJUsing radio data at 1.4 GHz from the Australia Telescope Compact Array (ATCA), we identify five head–tail (HT) galaxies in the central region of the Horologium–Reticulum Supercluster (HRS). Physical parameters of the HT galaxies were determined along with substructure in the HRS to probe the relationship between environment and radio properties. Using a density enhancement technique applied to 582 spectroscopic measurements in the 2°× 2° region about A3125/A3128, we find all five HT galaxies reside in regions of extremely high density (>100 galaxies Mpc−3). In fact, the environments surrounding HT galaxies are statistically denser than those environments surrounding non-HT galaxies and among the densest environments in a cluster. Additionally, the HT galaxies are found in regions of enhanced X-ray emission and we show that the enhanced density continues out to substructure groups of 10 members. We propose that it is the high densities that allow ram pressure to bend the HT galaxies as opposed to previously proposed mechanisms relying on exceptionally high peculiar velocities.
History
Publication title
Royal Astronomical Society. Monthly NoticesVolume
392Pagination
1070-1079ISSN
0035-8711Department/School
School of Natural SciencesPublisher
Wiley-Blackwell Publishing, IncPlace of publication
Commerce Place, 350 Main Street, Malden, USA, MARights statement
The definitive published version is available online at: http://interscience.wiley.comRepository Status
- Restricted