Diffuse X-Ray-emitting Gas in Major Mergers
MetadataShow full item record
Copyright © 2018 The American Astronomical Society. All rights reserved.
Using archived data from the Chandra X-ray telescope, we have extracted the diffuse X-ray emission from 49 equal-mass interacting/merging galaxy pairs in a merger sequence, from widely separated pairs to merger remnants. After the removal of contributions from unresolved point sources, we compared the diffuse thermal X-ray luminosity from hot gas (L X (gas)) with the global star formation rate (SFR). After correction for absorption within the target galaxy, we do not see a strong trend of L X (gas)/SFR with the SFR or merger stage for galaxies with SFR > 1 Myr -1 . For these galaxies, the median L X (gas)/SFR is 5.5 Ã—10 39 ((erg s -1 )/Myr -1 )), similar to that of normal spiral galaxies. These results suggest that stellar feedback in star-forming galaxies reaches an approximately steady-state condition, in which a relatively constant fraction of about 2% of the total energy output from supernovae and stellar winds is converted into X-ray flux. Three late-stage merger remnants with low SFRs and high K-band luminosities (L K ) have enhanced L X (gas)/SFR; their UV/IR/optical colors suggest that they are post-starburst galaxies, perhaps in the process of becoming ellipticals. Systems with L K < 10 10 L have lower L X (gas)/SFR ratios than the other galaxies in our sample, perhaps due to lower gravitational fields or lower metallicities. We see no relation between L X (gas)/SFR and Seyfert activity in this sample, suggesting that feedback from active galactic nuclei is not a major contributor to the hot gas in our sample galaxies.
Showing items related by title, author, creator and subject.
De Gasperin, F.; Intema, Hubertus; Ridl, J.; Salvato, M.; Van Weeren, R.; Bonafede, A.; Greiner, J.; Cassano, R.; Brüggen, M. (2017)Context. Galaxy clusters undergo mergers that can generate extended radio sources called radio relics. Radio relics are the consequence of merger-induced shocks that propagate in the intra cluster medium (ICM). Aims. In ...
Randall, S.; Clarke, T.; Van Weeren, R.; Intema, Hubertus; Dawson, W.; Mroczkowski, T.; Blanton, E.; Bulbul, E.; Giacintucci, S. (2016)We present results based on X-ray, optical, and radio observations of the massive galaxy cluster CIZA J0107.7+5408. We find that this system is a post-core-passage, dissociative, binary merger, with the optical galaxy ...
Mooley, K.; Nakar, E.; Hotokezaka, K.; Hallinan, G.; Corsi, A.; Frail, D.; Horesh, A.; Murphy, T.; Lenc, E.; Kaplan, D.; De, K.; Dobie, D.; Chandra, P.; Deller, A.; Gottlieb, O.; Kasliwal, M.; Kulkarni, S.; Myers, S.; Nissanke, S.; Piran, T.; Lynch, Christene; Bhalerao, V.; Bourke, S.; Bannister, K.; Singer, L. (2018)GW170817 was the first gravitational-wave detection of a binary neutron-star merger1. It was accompanied by radiation across the electromagnetic spectrum and localized2 to the galaxy NGC 4993 at a distance of 40 megaparsecs. ...