Ram pressure candidates in UNIONS. Issue 1 (28th October 2021)

• Record Type: Journal Article
• Authors: Roberts, Ian D; Parker, Laura C; Gwyn, Stephen; Hudson, Michael J; Carlberg, Raymond; McConnachie, Alan; Cuillandre, Jean-Charles; Chambers, Kenneth C; Duc, Pierre-Alain; Furusawa, Hisanori; Gavazzi, Raphael; Hill, Vanessa; Huber, Mark E; Ibata, Rodrigo; Kilbinger, Martin; Mei, Simona; Mellier, Yannick; Miyazaki, Satoshi; Oguri, Masamune; Wainscoat, Richard J
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 509:Issue 1(2022)
• Page Start: 1342
• Page End: 1357
• Publication Date: 2021-10-28
• Subjects: galaxies: clusters: general -- galaxies: evolution -- galaxies: irregular; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab3101
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present a search for disturbed, candidate ram pressure stripping galaxies across more than 50 spectroscopically selected SDSS groups and clusters. 48 ram pressure candidates are visually identified in these systems using high-quality UNIONS imaging from the Canada-France-Hawaii Telescope, covering ${\sim }6200\, \mathrm{deg^2}$ and ${\sim }2800\, \mathrm{deg^2}$ in the u - and r -bands, respectively. Ram pressure candidates are found in groups and clusters spanning a wide range in halo mass and include ∼30 ram pressure candidates in the group regime ( Mh < 10 14 ). The observed frequency of ram pressure candidates shows substantial scatter with group/cluster mass, but on average is larger in clusters ($M_h \ge 10^{14}\, \mathrm{M_\odot }$ ) than groups ($M_h \lt 10^{14}\, \mathrm{M_\odot }$ ) by a factor of ∼2. We find that ram pressure candidates are most commonly low-mass galaxies and have enhanced star formation rates relative to star-forming field galaxies. The enhancement in star formation is largely independent of galaxy mass and strongest for galaxies in clusters. As a result of the large survey footprint and excellent image quality from UNIONS, we are able to identify disturbed galaxies, potentially affected by ram pressure stripping, across a wide range of host environment.