AAS 205th Meeting, 9-13 January 2005
Session 166 Massive Embedded Stars Forming
Oral, Thursday, January 13, 2005, 2:00-3:30pm, Pacific 2/3

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[166.04] The Mass Function of High-Mass Submillimeter Clumps in NGC 7538 and M17

M. A. Reid, C. D. Wilson (McMaster University)

We present submillimeter continuum maps at 450 \mu m and 850 \mu m of the NGC~7538 and M17 star-forming regions, made using the Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. We used an automatic clump-finding algorithm (clfind2d) to identify 60-100 clumps in each image. We devised a technique for combining 450 \mu m and 850 \mu m maps to estimate the mean temperature of each clump. Using these temperatures, we compute the mass of each clump and analyse their differential and cumulative mass functions. We find that, as in low-mass star-forming regions, the clump mass function follows a Salpeter-like power-law for clump masses up to ~3000 M\odot. We compare the results of eight mm and submm continuum studies of the clump mass function in seven star-forming regions across five orders of magnitude in mass and find remarkable agreement among them. We interpret the ubiquity of Salpeter-like mass functions as evidence for the early determination of the stellar initial mass function (IMF), and hence as evidence that turbulent fragmentation is the process responsible for generating the IMF. We conclude that the physical processes responsible for generating the IMF should be scale-free. This research was supported by grants from the Natural Sciences and Engineering Research Council of Canada and by an Ontario Graduate Scholarship in Science and Technology.

The author(s) of this abstract have provided an email address for comments about the abstract: reidma@physics.mcmaster.ca

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© 2004. The American Astronomical Society.