High Mass Star Formation. II. The Mass Function of Submillimeter Clumps in M17

Abstract

We have mapped an approximately 5.5 by 5.5 pc portion of the M17 massive star-forming region in both 850 and 450 micron dust continuum emission using the Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). The maps reveal more than 100 dusty clumps with deconvolved linear sizes of 0.05--0.2 pc and masses of 0.8--120 solar masses, most of which are not associated with known mid-infrared point sources. Fitting the clump mass function with a double power law gives a mean power law exponent of alpha_high = -2.4 +/- 0.3 for the high-mass power law, consistent with the exponent of the Salpeter stellar mass function. We show that a lognormal clump mass distribution with a peak at about 4 solar masses produces as good a fit to the clump mass function as does a double power law. This 4 solar mass peak mass is well above the peak masses of both the stellar initial mass function and the mass function of clumps in low-mass star-forming regions. Despite the difference in intrinsic mass scale, the shape of the M17 clump mass function appears to be consistent with the shape of the core mass function in low-mass star-forming regions. Thus, we suggest that the clump mass function in high-mass star-forming regions may be a scaled-up version of that in low-mass regions, instead of its extension to higher masses.

33 pages, 6 figures, 3 tables. Accepted for publication in the Astrophysical Journal

Cited by in corpus (11)

• Theory of Star Formation
• Radiation-Hydrodynamic Simulations of Collapse and Fragmentation in Massive Protostellar Cores
• The young stellar population in M17 revealed by Chandra
• The Perils of Clumpfind: The Mass Spectrum of Sub-structures in Molecular Clouds
• The relationship between the prestellar core mass function and the stellar initial mass function
• The Stellar Mass Spectrum in Warm and Dusty Gas: Deviations from Salpeter in the Galactic Centre and in Circum-Nuclear Starburst Regions
• High Mass Star Formation. III. The Functional Form of the Submillimeter Clump Mass Function
• Massive Clumps in the NGC 6334 Star Forming Region
• On the fidelity of the core mass functions derived from dust column density data
• The interstellar medium of the Antennae Galaxies
• Astrophysics in 2006