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Date and Time of the Query: 2019-04-21 T13:46:59 PDT
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For refcode 2003ApJ...582..668B:
Retrieve 190 NED objects in this reference.
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Copyright by American Astronomical Society. Reproduced by permission
2003ApJ...582..668B Tidally Triggered Star Formation in Close Pairs of Galaxies. II. Constraints on Burst Strengths and Ages Elizabeth Barton Gillespie Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721; bgillespie@as.arizona.edu and Margaret J. Geller and Scott J. Kenyon Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138; mgeller@cfa.harvard.edu, skenyon@cfa.harvard.edu Received 2002 June 17; accepted 2002 September 16 ABSTRACT Galaxy-galaxy interactions rearrange the baryons in galaxies and trigger substantial star formation; the aggregate effects of these interactions on the evolutionary histories of galaxies in the universe are poorly understood. We combine B- and R-band photometry and optical spectroscopy to estimate the strengths and timescales of bursts of triggered star formation in the centers of 190 galaxies in pairs and compact groups. Based on an analysis of the measured colors and EW(H{alpha}), we characterize the preexisting and triggered populations separately. The best-fitting burst scenarios assume stronger reddening corrections for line emission than for the continuum and continuous star formation lasting for >~100 Myr. The most realistic scenarios require an initial mass function that is deficient in the highest mass stars. The color of the preexisting stellar population is the most significant source of uncertainty. Triggered star formation contributes substantially (probably >~50%) to the R-band flux in the central regions of several galaxies; tidal tails do not necessarily accompany this star formation. Many of the galaxies in our sample have bluer centers than outskirts, suggesting that pre- or nonmerger interactions may lead to evolution along the Hubble sequence. These objects would appear blue and compact at higher redshifts; the older, redder outskirts of the disks would be difficult to detect. Our data indicate that galaxies with larger separations on the sky contain weaker, and probably older, bursts of star formation on average. However, confirmation of these trends requires further constraints on the colors of the older stellar populations and on the reddening for individual galaxies. Subject headings: galaxies: evolution - galaxies: fundamental parameters - galaxies: interactions - galaxies: kinematics and dynamics - galaxies: structure
Retrieve 190 NED objects in this reference.
Please click here for ADS abstract

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