2017/12/11 by Beverly J. Smith, Kristen Campbell, Curtis Struck +5
Physics and Astronomy · #Absorption (acoustics) #Active galactic nucleus #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Spiral galaxy #Star formation #Stars #Supernova #astro-ph.GA
paper · pdf · doi:10.3847/1538-3881/aaa1a6
Astronomical Journal, in press; 43 pages, 24 figures
arxiv created 2017/12/11 · openalex created_date 2017/12/22 · openalex publication_date 2018/01/23 · arxiv updated 2018/02/07 · openalex updated_date 2026/08/05
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 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 M ☉ yr −1 . For these galaxies, the median L X (gas)/SFR is 5.5 × 10 39 ((erg s −1 )/ M ☉ 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 ☉ 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.