VESTIGE OF THE STAR CLUSTER BURST IN M51

Journal Article · Wed Jan 20 04:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/709/1/411· OSTI ID:21392338

Hwang, Narae ^[1]

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1. National Astronomical Observatory of Japan, 2-21-1 Osawa Mitaka, Tokyo 181-8588 (Japan)

We present a study of the star cluster formation in M51 based on the image data taken with Advanced Camera for Surveys (ACS) and Wide Field Planetary Camera 2 (WFPC2) of Hubble Space Telescope (HST). We have derived the star cluster formation rate using the ages and masses of about 2000 star clusters estimated by comparing photometric data (F336W, F435W, F555W, and F814W) with theoretical population synthesis models. The star cluster formation rate increased significantly during the period of 100-250 Myr ago. This period roughly coincides with the epoch of dynamical encounters of two galaxies, NGC 5194 and NGC 5195, expected by theoretical models. The age distribution of the star clusters also shows two peaks at about 100 Myr and 250 Myr ago. The star cluster mass ranges from 10{sup 3} to 10{sup 6} M{sub sun} and the mass function can be represented by a power law with an index ranging from alpha = -2.23 +- 0.34 for t < 10 Myr to alpha = -1.37 +- 0.11 for t>100 Myr. The mass function of star clusters older than 10 Myr also appears to display the steepest distribution with alpha approx -1.50 at around 200 Myr ago, near the expected epoch of the galaxy interaction. We also confirm the correlations of cluster size increasing with cluster mass (with a best-fit slope of 0.16 +- 0.02), and with cluster age (0.14 +- 0.03).

• OSTI ID: 21392338
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 709; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CAMERAS
DOCUMENT TYPES
GALAXIES
INDEXES
MASS
STAR CLUSTERS
TELESCOPES