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Title: Multi-wavelength studies of spectacular ram-pressure stripping of a galaxy. II. Star formation in the tail

With multiband photometric data in public archives, we detected four intracluster star-forming regions in the Virgo Cluster. Two of them were at a projected distance of 35 kpc from NGC 4388 and the other two were 66 kpc away. Our new spectroscopic observations revealed that their recessional velocities were comparable to the ram-pressure-stripped tail of NGC 4388 and confirmed the association. The stellar mass of the star-forming regions ranged from 10{sup 4} to 10{sup 4.5} M {sub ☉} except for that of the faintest one, which was <10{sup 3} M {sub ☉}. The metallicity was comparable to a solar abundance and the age of the stars was ∼10{sup 6.8} yr. Their young stellar age meant that the star formation should have started after the gas was stripped from NGC 4388. This implied in situ condensation of the stripped gas. We also found that two star-forming regions were located near the leading edge of a filamentary dark cloud. The extinction of the filament was smaller than that derived from the Balmer decrement of the star-forming regions, implying that the dust in the filament would be locally dense around the star-forming regions.
Authors:
 [1] ; ; ;  [2] ;  [3] ;  [4] ;  [5] ;  [6]
  1. Optical and Infrared Astronomy Division, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  2. Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0011 (Japan)
  3. Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
  4. Sydney Institute for Astronomy, School of Physics, The University of Sydney, 44 Rosehill Street, Redfern, NSW 2006 (Australia)
  5. Subaru Telescope, 650 North A'ohoku Place, Hilo, HI 96720 (United States)
  6. Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)
Publication Date:
OSTI Identifier:
22341977
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; ABUNDANCE; COMPARATIVE EVALUATIONS; DISTANCE; DUSTS; FILAMENTS; GALAXIES; MASS; METALLICITY; PHOTOMETRY; STAR CLUSTERS; STAR EVOLUTION; STARS; WAVELENGTHS