Panchromatic Hubble Andromeda Treasury. XVIII. The High-mass Truncation of the Star Cluster Mass Function

Journal Article · Thu Apr 20 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA6A1F· OSTI ID:22872787

Johnson, L. Clifton; Sandstrom, Karin ^[1]; Seth, Anil C.; Bell, Timothy A. ^[2]; Dalcanton, Julianne J.; Beerman, Lori C.; Williams, Benjamin F. ^[3]; Fouesneau, Morgan ^[4]; Weisz, Daniel R. ^[5]

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1. Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States)
2. Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, UT 84112 (United States)
3. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States)
4. Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
5. Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

We measure the mass function for a sample of 840 young star clusters with ages between 10 and 300 Myr observed by the Panchromatic Hubble Andromeda Treasury (PHAT) survey in M31. The data show clear evidence of a high-mass truncation: only 15 clusters more massive than 10{sup 4} M{sub ⊙} are observed, compared to the ∼100 expected for a canonical M{sup −2} pure power-law mass function with the same total number of clusters above the catalog completeness limit. Adopting a Schechter function parameterization, we fit a characteristic truncation mass of M{sub c}=8.5{sub −1.8}{sup +2.8}×10{sup 3} M {sub ☉}. Although previous studies have measured cluster mass function truncations, the characteristic truncation mass we measure is the lowest ever reported. Combining this M31 measurement with previous results, we find that the cluster mass function truncation correlates strongly with the characteristic star formation rate surface density of the host galaxy, where M{sub c}∝〈Σ{sub SFR}〉{sup ∼1.1}. We also find evidence that suggests the observed M {sub c}–Σ{sub SFR} relation also applies to globular clusters, linking the two populations via a common formation pathway. If so, globular cluster mass functions could be useful tools for constraining the star formation properties of their progenitor host galaxies in the early universe.

• OSTI ID: 22872787
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 839; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CATALOGS
COMPARATIVE EVALUATIONS
GALAXIES
MASS
STAR CLUSTERS
STAR EVOLUTION
STARS
UNIVERSE