EDP Sciences
Free access
Issue
A&A
Volume 433, Number 2, April II 2005
Page(s) 565 - 577
Section Interstellar and circumstellar matter
DOI http://dx.doi.org/10.1051/0004-6361:20041946


A&A 433, 565-577 (2005)
DOI: 10.1051/0004-6361:20041946

Triggered massive-star formation on the borders of Galactic H II regions

I. A search for "collect and collapse" candidates
L. Deharveng, A. Zavagno and J. Caplan

Laboratoire d'Astrophysique de Marseille, 2 Place Le Verrier, 13248 Marseille Cedex 4, France
    e-mail: lise.deharveng@oamp.fr

(Received 3 September 2004 / Accepted 30 November 2004 )

Abstract
Young massive stars or clusters are often observed at the peripheries of H II regions. What triggers star formation at such locations? Among the scenarios that have been proposed, the "collect and collapse" process is particularly attractive because it permits the formation of massive objects via the fragmentation of the dense shocked layer of neutral gas surrounding the expanding ionized zone. However, until our recent article on Sh 104, it had not been convincingly demonstrated that this process actually takes place. In the present paper we present our selection of seventeen candidate regions for this process; all show high-luminosity near-IR clusters and/or mid-IR point sources at their peripheries. The reality of a "collect and collapse" origin of these presumably second-generation stars and clusters will be discussed in forthcoming papers, using new near-IR and millimetre observations.


Key words: stars: formation -- stars: early-type -- ISM: H II regions

SIMBAD Objects



© ESO 2005