OUTFLOW FEEDBACK REGULATED MASSIVE STAR FORMATION IN PARSEC-SCALE CLUSTER-FORMING CLUMPS

Journal Article · Wed Jan 20 00:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/709/1/27· OSTI ID:21392366

Peng, Wang; Abel, Tom ^[1]; Zhiyun, Li ^[2]; Nakamura, Fumitaka ^[3]

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1. KIPAC, SLAC, and Physics Department, Stanford University, Menlo Park, CA 94025 (United States)
2. Astronomy Department, P.O. Box 400325, University of Virginia, Charlottesville, VA 22904 (United States)
3. Faculty of Education, Niigata University, 8050 Ikarashi-2, Niigata 950-2181 (Japan)

We investigate massive star formation in turbulent, magnetized, parsec-scale clumps of molecular clouds including protostellar outflow feedback using three-dimensional numerical simulations of effective resolution 2048{sup 3}. The calculations are carried out using a block structured adaptive mesh refinement code that solves the ideal magnetohydrodynamic equations including self-gravity and implements accreting sink particles. We find that, in the absence of regulation by magnetic fields and outflow feedback, massive stars form readily in a turbulent, moderately condensed clump of approx1600 M{sub sun} (containing approx10{sup 2} initial Jeans masses), along with a cluster of hundreds of lower mass stars. The massive stars are fed at high rates by (1) transient dense filaments produced by large-scale turbulent compression at early times and (2) by the clump-wide global collapse resulting from turbulence decay at late times. In both cases, the bulk of the massive star's mass is supplied from outside a 0.1 pc-sized 'core' that surrounds the star. In our simulation, the massive star is clump-fed rather than core-fed. The need for large-scale feeding makes the massive star formation prone to regulation by outflow feedback, which directly opposes the feeding processes. The outflows reduce the mass accretion rates onto the massive stars by breaking up the dense filaments that feed the massive star formation at early times, and by collectively slowing down the global collapse that fuels the massive star formation at late times. The latter is aided by a moderate magnetic field of strength in the observed range (corresponding to a dimensionless clump mass-to-flux ratio lambdaapprox a few); the field allows the outflow momenta to be deposited more efficiently inside the clump. We conclude that the massive star formation in our simulated turbulent, magnetized, parsec-scale clump is outflow-regulated and clump-fed. An important implication is that the formation of low-mass stars in a dense clump can affect the formation of massive stars in the same clump, through their outflow feedback on the clump dynamics. In a companion paper, we discuss the properties of the lower mass cluster members formed along with the massive stars, including their mass distribution and spatial clustering.

• OSTI ID: 21392366
• Journal Information: Astrophysical Journal, Vol. 709, Issue 1; Other Information: DOI: 10.1088/0004-637X/709/1/27; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COMPUTERIZED SIMULATION
EQUATIONS
GRAVITATION
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MASS
MASS DISTRIBUTION
STARS
THREE-DIMENSIONAL CALCULATIONS
TURBULENCE
DISTRIBUTION
FLUID MECHANICS
HYDRODYNAMICS
MECHANICS
SIMULATION
SPATIAL DISTRIBUTION