CaltechAUTHORS
Published June 10, 2017 | Version Published
Journal Article Open

Hierarchical Star Formation in Turbulent Media: Evidence from Young Star Clusters

Creators

  • 1. ROR icon University of Massachusetts Amherst
  • 2. ROR icon IBM Research - Thomas J. Watson Research Center
  • 3. ROR icon Stockholm University
  • 4. ROR icon Space Telescope Science Institute
  • 5. ROR icon California Institute of Technology
  • 6. ROR icon University of Wyoming
  • 7. ROR icon Durham University
  • 8. ROR icon University of Wisconsin–Madison
  • 9. ROR icon Heidelberg University
  • 10. ROR icon Max Planck Institute for Astronomy
  • 11. ROR icon New Mexico State University
  • 12. ROR icon Australian National University

Abstract

We present an analysis of the positions and ages of young star clusters in eight local galaxies to investigate the connection between the age difference and separation of cluster pairs. We find that star clusters do not form uniformly but instead are distributed so that the age difference increases with the cluster pair separation to the 0.25–0.6 power, and that the maximum size over which star formation is physically correlated ranges from ~200 pc to ~1 kpc. The observed trends between age difference and separation suggest that cluster formation is hierarchical both in space and time: clusters that are close to each other are more similar in age than clusters born further apart. The temporal correlations between stellar aggregates have slopes that are consistent with predictions of turbulence acting as the primary driver of star formation. The velocity associated with the maximum size is proportional to the galaxy's shear, suggesting that the galactic environment influences the maximum size of the star-forming structures.

Additional Information

© 2017 American Astronomical Society. Received 2016 December 8. Accepted 2017 May 16. Published 2017 June 8. We are indebted to an anonymous referee for careful reading of this manuscript and for providing comments that have improved the scientific outcome and quality of the paper. We also appreciate the very useful discussions and comments on this work by R. Klessen, D. Kruijssen, and B. Gaches. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, under NASA Contract NAS 5–26555. These observations are associated with Program 13364 (LEGUS). Support for Program 13364 was provided by NASA through a grant from the Space Telescope Science Institute. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. D.A.G. kindly acknowledges financial support by the German Research Foundation (DFG) through program GO 1659/3-2.

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Additional details

Identifiers

Eprint ID
79080
Resolver ID
CaltechAUTHORS:20170713-104625485

Funding

NASA
NAS 5–26555
NASA
13364
NASA/JPL/Caltech
Deutsche Forschungsgemeinschaft (DFG)
GO 1659/3-2

Dates

Created
2017-07-13
Created from EPrint's datestamp field
Updated
2021-11-15
Created from EPrint's last_modified field