THE OBSERVABLE PRESTELLAR PHASE OF THE INITIAL MASS FUNCTION

Journal Article · Tue Nov 15 04:00:00 EST 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/741/1/L22· OSTI ID:22047387

Padoan, Paolo ^[1]; Nordlund, Ake ^[2]

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1. ICREA and ICC, University of Barcelona, Marti i Franques 1, E-08028 Barcelona (Spain)
2. Centre for Star and Planet Formation and Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)

The observed similarities between the mass function of prestellar cores (CMF) and the stellar initial mass function (IMF) have led to the suggestion that the IMF is already largely determined in the gas phase. However, theoretical arguments show that the CMF may differ significantly from the IMF. In this Letter, we study the relation between the CMF and the IMF, as predicted by the IMF model of Padoan and Nordlund. We show that (1) the observed mass of prestellar cores is on average a few times smaller than that of the stellar systems they generate; (2) the CMF rises monotonically with decreasing mass, with a noticeable change in slope at approximately 3-5 M{sub Sun }, depending on mean density; (3) the selection of cores with masses larger than half their Bonnor-Ebert mass yields a CMF approximately consistent with the system IMF, rescaled in mass by the same factor as our model IMF, and therefore suitable to estimate the local efficiency of star formation, and to study the dependence of the IMF peak on cloud properties; and (4) only one in five pre-brown-dwarf core candidates is a true progenitor to a brown dwarf.

• OSTI ID: 22047387
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 741; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
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COSMOLOGY
DENSITY
DWARF STARS
EFFICIENCY
MAGNETOHYDRODYNAMICS
MASS
STAR EVOLUTION
TURBULENCE