CaltechAUTHORS
Published November 2010 | Version Published
Journal Article Open

The spatial distribution of star formation in the solar neighbourhood: do all stars form in dense clusters?

Creators

  • 1. ROR icon University of Exeter
  • 2. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 3. ROR icon University of Cambridge
  • 4. ROR icon Smith College
  • 5. ROR icon University of Toledo
  • 6. ROR icon NOIRLab
  • 7. ROR icon The University of Texas at Austin
  • 8. ROR icon Herzberg Institute of Astrophysics
  • 9. ROR icon University of Victoria
  • 10. ROR icon University of Hawaii at Manoa
  • 11. ROR icon European Space Astronomy Centre
  • 12. ROR icon Dublin Institute For Advanced Studies
  • 13. ROR icon UNSW Sydney

Abstract

We present a global study of low-mass, young stellar object (YSO) surface densities (Σ) in nearby (<500 pc) star-forming regions based on a comprehensive collection of Spitzer Space Telescope surveys. We show that the distribution of YSO surface densities in the solar neighbourhood is a smooth distribution, being adequately described by a lognormal function from a few to 10^3 YSOs pc^(−2), with a peak at ~22 stars pc^(−2) and a dispersion of σ_(log10Σ) ~0.85. We do not find evidence for multiple discrete modes of star formation (e.g. clustered and distributed). Comparing the observed surface density distribution to previously reported surface density threshold definitions of clusters, we find that the fraction of stars in clusters is crucially dependent on the adopted definitions, ranging from 40 to 90 per cent. However, we find that only a low fraction (<26 per cent) of stars are formed in dense environments where their formation/evolution (along with their circumstellar discs and/or planets) may be affected by the close proximity of their low-mass neighbours.

Additional Information

© 2010 The Authors. Journal compilation © 2010 RAS. Accepted 2010 September 4. Received 2010 August 13; in original form 2010 June 18. Article first published online: 28 Sep 2010. We would like to thank Mark Gieles, Michael Meyer, August Muench, Dawn Peterson, Thomas Robitaille and Scott Schnee for their thoughtful feedback on the research. EB gratefully thanks the Royal Astronomical Society for their generous travel support. NB is supported by an STFC advanced fellowship. TPR would like to thank Science Foundation Ireland for support under grant 07/RFP/PHYF790. Support for this work, part of the Spitzer Legacy Science Program, was provided by NASA through contract 1224608 and 1288664 issued by the Jet Propulsion Laboratory, California Institute of Technology, under NASA contract 1407. NJE acknowledges support by NSF Grant AST-0607793.

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Additional details

Identifiers

Eprint ID
23625
Resolver ID
CaltechAUTHORS:20110511-074758793

Funding

Science and Technology Facilities Council (STFC)
Science Foundation, Ireland
07/RFP/PHYF790
NASA
1224608
NASA
1288664
NASA
1407
NSF
AST-0607793

Dates

Created
2011-05-11
Created from EPrint's datestamp field
Updated
2021-11-09
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC)