EPoS Contribution
EPoS Contribution
Physical and Chemical Properties of Massive Quiescent Cores in Orion

Di Li
NAOC, Beijing, CN
We mapped relatively quiescent regions of the Orion Molecular Cloud using FCRAO, Arizona 12m, CSO, GBT, Spitzer, CARMA, and VLA, tracing the gas and dust from ~1 pc scale down to <0.01 pc scales. Our findings include 1) the mean resolved core masses in Orion is one order of magnitude higher than that in low mass star forming regions (LMSF). 2) The core mass function (CMF) is flatter than Salpeter IMF. 3) The temperature and level of turbulence are higher than those in LMSF with similar trend of dropping from outside to inside suggesting predominently outside heating and driving. 4) Substantial fraction of the cores are supercritical unless the static magnetic field is in the milli-gauss range. 5) Individual cores have volume density higher than 109 cc. It is unclear how the fragmentation can be stopped if higher stellar mass is to be formed. 6) N2H+ is displaced from dust continuum and stellar energetics seem to have a more prominent role in shaping the chemistry than radiation field.
Collaborators:
Z. Ren
N. Chapman
Q. Zhang
P. Goldsmith
T. Velusamy
Key publication

Suggested Sessions: Cores