Understanding How Star Formation Proceeds in the Perseus and
Ophiuchus Molecular Clouds
Doug JOHNSTONE
NRCC, Herzberg Institute of Astrophysics, Canada
Résumé :
The nearby Perseus and Ophiuchus molecular clouds are exceptional
laboratories for testing the earliest phases of star formation.
Careful consideration of the multi-wavelength surveys of these
clouds (in particular 2Mass, Spitzer c2d, and COMPLETE) allows us
to measure the column density distributions of the bulk cloud, the
location and kinematics of the dense stellar-massed cores, and the
distribution of the protostars. As such we can now provide strong
constraints for theoretical models or simulations wishing to
explain the manner in which stars form within a cloud. Highlights
of our results are (1) most of the mass of the cloud is at low
column density, (2) dense cores form only in high column density
regions, (3) the mass distribution of the dense cores is similar to
the IMF, (4) dense cores are mostly thermally supported, (5) dense
cores contain only a few percent of the cloud mass, (6) the more
concentrated cores are most likely to contain embedded protostars,
and (7) the dense cores are not randomly located within the the
molecular cloud, suggesting possible triggering mechanisms for
their creation. In this talk, I will discuss each of these
important results and place them in context with theoretical models
and simulations of star formation.
