Different evolutionary stages in massive star formation

Mopra Observations of G305.2+0.2: Massive Star Formation at Different Evolutionary Stages?

We have successfully used a new on-the-fly mapping technique with the Mopra radiotelescope to image G305.2+0.2 in transitions of CO, HCO, N2H , CH3CN and CH3OH. All these species appear to be concentrated towards the infrared-quiet methanol maser site G305A (G305.21+0.21). We suggest that this region contains an extremely deeply embedded site of massive star formation, with comparable qualities...

Two massive star forming regions at early evolutionary stages

We report sensitive ATCA radio continuum observations toward IRAS 15596−5301 and 16272−4837, two luminous objects (L > 2 × 10L⊙) thought to represent massive star forming regions in early stages of evolution (due to previously undetected radio emission at the 1σ level of 2 mJy per beam). Also reported are 1.2 millimeter continuum and a series of molecular line observations made with the SEST te...

Massive Star Formation

Fragmentation in massive star formation.

Studies of evolved massive stars indicate that they form in a clustered mode. During the earliest evolutionary stages, these regions are embedded within their natal cores. Here we present high-spatial-resolution interferometric dust continuum observations disentangling the cluster-like structure of a young massive star-forming region. The derived protocluster mass distribution is consistent wit...

Massive Star and Star Cluster Formation

I review the status of massive star formation theories: accretion from collapsing, massive, turbulent cores; competitive accretion; and stellar collisions. I conclude the observational and theoretical evidence favors the first of these models. I then discuss: the initial conditions of star cluster formation as traced by infrared dark clouds; the cluster formation timescale; and comparison of th...