Testing Triggered Star Formation in Six H II Regions

Type Journal Article
Names William J. Dirienzo, Rémy Indebetouw, Crystal Brogan, Claudia J. Cyganowski, Ed Churchwell, Rachel K. Friesen
Publication The Astronomical Journal
Volume 144
Pages 173
Journal Abbreviation The Astronomical Journal
Date December 1, 2012
DOI 10.1088/0004-6256/144/6/173;
ISSN 0004-6256
URL http://adsabs.harvard.edu/abs/2012AJ....144..173D
Library Catalog NASA ADS
Abstract We investigated six H II regions with infrared, bright rimmed bubble or cometary morphology, in search of quantitative evidence for triggered star formation, both collect and collapse and radiatively driven implosion (RDI). We identified and classified 458 young stellar objects (YSOs) in and around the H II regions. YSOs were determined by fitting a collection of radiative transfer model spectral energy distributions to infrared photometry for a large sample of point sources. We determined areas where there exist enhanced populations of relatively unevolved YSOs on the bright rims of these regions, suggesting that star formation has been triggered there. We further investigated the physical properties of the regions by using radio continuum emission as a proxy for ionizing flux powering the H II regions, and 13CO (1-0) observations to measure masses and gravitational stability of molecular clumps. We used an analytical model of collect and collapse triggered star formation, as well as a simulation of RDI, and thus we compare the observed properties of the molecular gas with those predicted in the triggering scenarios. Notably, those regions in our sample that show evidence of cometary, or "blister," morphology are more likely to show evidence of triggering.
Tags H II REGIONS, ISM: bubbles, STARS: FORMATION, stars: protostars
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