{ "id": "1712.04049", "version": "v1", "published": "2017-12-11T22:05:43.000Z", "updated": "2017-12-11T22:05:43.000Z", "title": "Diffuse X-ray-emitting Gas in Major Mergers", "authors": [ "Beverly J. Smith", "Kristen Campbell", "Curtis Struck", "Roberto Soria", "Douglas Swartz", "Macon Magno", "Brianne Dunn", "Mark L. Giroux" ], "comment": "Astronomical Journal, in press; 43 pages, 24 figures", "categories": [ "astro-ph.GA" ], "abstract": "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 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 strong trend of L(X)(gas)/SFR with SFR or merger stage for galaxies with SFR > 1 M(sun) yr^-1. For these galaxies, the median L(X)(gas)/SFR is 5.5 X 10^39 ((erg s^-1)/M(sun) yr^-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(sun) 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.", "revisions": [ { "version": "v1", "updated": "2017-12-11T22:05:43.000Z" } ], "analyses": { "keywords": [ "diffuse x-ray-emitting gas", "major mergers", "diffuse thermal x-ray luminosity", "hot gas", "global star formation rate" ], "note": { "typesetting": "TeX", "pages": 43, "language": "en", "license": "arXiv", "status": "editable" } } }