A new method to unveil embedded stellar clusters
- Author(s)
- Marco Lombardi, Charles J. Lada, Joao Alves
- Abstract
In this paper we present a novel method to identify and characterizestellar clusters deeply embedded in a dark molecular cloud. The methodis based on measuring stellar surface density in wide-field infraredimages using star counting techniques. It takes advantage of thediffering H-band luminosity functions (HLFs) of field stars and youngstellar populations and is able to statistically associate each star inan image as a member of either the background stellar population or ayoung stellar population projected on or near the cloud. Moreover, thetechnique corrects for the effects of differential extinction towardeach individual star. We have tested this method against simulations aswell as observations. In particular, we have applied the method to 2MASS point sources observed in the Orion A and B complexes, and the resultsobtained compare very well with those obtained from deep Spitzer andChandra observations where presence of infrared excess or X-ray emissiondirectly determines membership status for every star. Additionally, ourmethod also identifies unobscured clusters and a low resolution versionof the Orion stellar surface density map shows clearly the relativelyunobscured and diffuse OB 1a and 1b sub-groups and provides usefulinsights on their spatial distribution.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Università degli Studi di Milano-Bicocca, Harvard-Smithsonian Center for Astrophysics
- Journal
- Astronomy & Astrophysics
- Volume
- 608
- No. of pages
- 13
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/201630193
- Publication date
- 11-2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/79dea98d-301d-4e22-a530-cb053b989a15