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Title: Angular momenta, dynamical masses, and mergers of brightest cluster galaxies

Using the VIMOS integral field unit (IFU) spectrograph on the Very Large Telescope, we have spatially mapped the kinematic properties of 10 nearby brightest cluster galaxies (BCGs) and 4 BCG companion galaxies located within a redshift of z = 0.1. In the hierarchical formation model, these massive galaxies (10{sup 10.5} M {sub ☉} < M {sub dyn} < 10{sup 11.9} M {sub ☉}) are expected to undergo more mergers than lower mass galaxies, and simulations show that dry minor mergers can remove angular momentum. We test whether BCGs have low angular momenta by using the λ {sub Re} parameter developed by the SAURON and ATLAS{sup 3D} teams and combine our kinematics with Sloan Digital Sky Survey photometry to analyze the BCGs' merger status. We find that 30% (3/10) of the BCGs and 100% of the companion galaxies (4/4) are fast rotators as defined by the ATLAS{sup 3D} criteria. Our fastest rotating BCG has a λ {sub Re} = 0.35 ± 0.05. We increase the number of BCGs analyzed from 1 in the combined SAURON and ATLAS{sup 3D} surveys to 11 BCGs total and find that above M {sub dyn} ∼ 11.5 M {sub ☉}, virtually all galaxies, regardless of environment,more » are slow rotators. To search for signs of recent merging, we analyze the photometry of each system and use the G – M {sub 20} selection criteria to identify mergers. We find that 40% ± 20% of our BCGs are currently undergoing or have recently undergone a merger (within 0.2 Gyr). Surprisingly, we find no correlation between galaxies with high angular momentum and morphological signatures of merging.« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)
  2. Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia)
  3. Department of Astronomy, University of Texas at Austin, 1 University Station C1400, Austin, TX 78712 (United States)
  4. Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305-4085 (United States)
  5. Centre for Astrophysics and Supercomputing, Swinburne University, P.O. Box 218, Hawthorn, VIC 3122 (Australia)
  6. Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia)
Publication Date:
OSTI Identifier:
22341901
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 778; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANGULAR MOMENTUM; CORRELATIONS; EVOLUTION; GALAXIES; GALAXY CLUSTERS; MASS; PHOTOMETRY; RED SHIFT; SIMULATION; SKY; SPECTROSCOPY; TELESCOPES