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Title: Late-stage galaxy mergers in cosmos to z ∼ 1

The role of major mergers in galaxy and black hole formation is not well-constrained. To help address this, we develop an automated method to identify late-stage galaxy mergers before coalescence of the galactic cores. The resulting sample of mergers is distinct from those obtained using pair-finding and morphological indicators. Our method relies on median-filtering of high-resolution images to distinguish two concentrated galaxy nuclei at small separations. This method does not rely on low surface brightness features to identify mergers, and is therefore reliable to high redshift. Using mock images, we derive statistical contamination and incompleteness corrections for the fraction of late-stage mergers. The mock images show that our method returns an uncontaminated (<10%) sample of mergers with projected separations between 2.2 and 8 kpc out to z∼1. We apply our new method to a magnitude-limited (m{sub FW} {sub 814}<23) sample of 44,164 galaxies from the COSMOS HST/ACS catalog. Using a mass-complete sample with logM{sub ∗}/M{sub ⊙}>10.6 and 0.25
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ; ;  [5] ; ;  [6] ;  [7] ;  [8] ; ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [14]
  1. Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)
  2. Max-Planck-Institut für extraterrestrische Physik, D-84571 Garching (Germany)
  3. Institute of Astronomy, Department of Physics, ETH Zürich, CH-8093 Zürich (Switzerland)
  4. National Optical Astronomy Observatory, Tucson, AZ 85719 (United States)
  5. Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)
  6. California Institute of Technology, Pasadena, CA 91125 (United States)
  7. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
  8. 23, rue d’Yerres, F-91230 Montgeron (France)
  9. Aix Marseille Université, CNRS, LAM (Laboratoire dAstrophysique de Marseille), F-13388, Marseille (France)
  10. Max-Planck-Institut für Astronomie, D-69117 Heidelberg (Germany)
  11. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
  12. Astrophysical Observatory, CUNY, College of Staten Island, NY 10314 (United States)
  13. National Radio Astronomy Observatory/NAASC, Charlottesville, VA 22903 (United States)
  14. Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Copenhagen, DK-2100 (Denmark)
Publication Date:
OSTI Identifier:
22342199
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 148; Journal Issue: 6; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; BRIGHTNESS; CATALOGS; COALESCENCE; CORRECTIONS; FILTERS; GALAXIES; GALAXY NUCLEI; GROWTH; IMAGE PROCESSING; IMAGES; INTERACTIONS; MASS; NONLUMINOUS MATTER; RED SHIFT; RESOLUTION; STARS; SURFACES; UNIVERSE; X RADIATION