Spitzer Space Telescope - Archive Research Proposal #50623


Bridging the gap: A Spitzer Census of Intermediate-Mass Star Forming Regions
from Galactic Surveys. 

Principal Investigator: Charles Kerton
           Institution: Iowa State University

     Technical Contact: Charles Kerton, Iowa State University

Co-Investigators: 
Chip Kobulnicky, University of Wyoming                                

Science Category: star formation 
Dollars Approved: 75000 

Abstract:
High-mass star formation (M>10 Msun) appears to proceed through different
channels than low-mass star formation (M<2 Msun). The differences between these
two regimes are thought to include not only the timescales and masses involved
but also the initial conditions and operative physics within the parent
molecular clouds. We propose an archival analysis of ~50 *intermediate-mass*
star formation (SF) regions that straddle the boundary between these two
regimes---regions forming stars up to 4-8 Msun. These, relatively unknown and
unstudied IR sources are selected by their IRAS colors and lie within the
Spitzer GLIMPSE+MIPSGAL legacy survey fields. Compared to their more famous
high-mass SF cousins (e.g., the Westerhout "W" HII objects), these regions are
radio-quiet, relatively nearby, and structurally less complex. We will use
complementary public-domain 13CO, 21-cm, and radio continuum Galactic surveys to
1) confirm the intermediate-mass SF nature of these objects, 2) compile a
catalog and an atlas of mid-IR morphologies, 3) estimate distances, 4) calculate
total luminosities and gas masses of affiliated molecular and atomic material,
and 5) identify associated young stellar objects using IRAC+[24] colors. This
work will provide a benchmark useful for contrasting the star formation process
in both lower-mass and higher-mass SF environments.