Arp 65 interaction debris: massive H I displacement and star formation

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...

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...

Propagating Star Formation in the Collisional Ring Galaxy Arp 10

Propagating star formation in a collisional ring galaxy Arp 10 is investigated by a complex approach , which includes the broad-and narrow-band photometry, long-slit spectroscopy, and scanning Fabry-Perot spectroscopy. The ionized gas velocity field obtained with best spatial resolution to date indicates a non-isotropic expansion of the outer ring with a maximum velocity 110 km s −1. Strong ver...

Radiation Pressure in Massive Star Formation

Stars with masses of ∼ 20 M⊙ have short Kelvin times that enable them to reach the main sequence while still accreting from their natal clouds. The resulting nuclear burning produces a huge luminosity and a correspondingly large radiation pressure force on dust grains in the accreting gas. This effect may limit the upper mass of stars that can form by accretion. Indeed, simulations and analytic...