The Inevitable Future of the Starless Core Barnard 68

Author(s)
Andreas Burkert, João Alves
Abstract

Dense, small molecular cloud cores have been identified as the direct progenitors of stars. One of the best studied examples is Barnard 68which is considered a prototype stable, spherical gas core, confined by a diffuse high-pressure environment. Observations of its radial density structure, however, indicate that Barnard 68 should be gravitationally unstable and collapsing, which appears to be inconsistent with its inferred long lifetime and stability. We argue that Barnard 68 is currently experiencing a fatal collision with another small core which will lead to gravitational collapse. Despite the fact that this system is still in an early phase of interaction, our numerical simulation simply that the future gravitational collapse is already detectable in the outer surface density structure of the globule which mimics the profile of a gravitationally unstable Bonnor-Ebert sphere. Within the next 2 × 105 years, Barnard 68 will condense into a low-mass solar-type star(s), formed in isolation, and surrounded by diffuse, hot interstellar gas. As witnessed in situ for Barnard 68, core mergers might in general play an important role in triggering star formation and shaping the molecular core mass distribution and by that also the stellar initial mass function.

Organisation(s)
Department of Astrophysics
External organisation(s)
Ludwig-Maximilians-Universität München
Journal
The Astrophysical Journal: an international review of astronomy and astronomical physics
Volume
695
Pages
1308-1314
ISSN
0004-637X
DOI
https://doi.org/10.1088/0004-637X/695/2/1308
Publication date
04-2009
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/683e594c-b440-444c-88cf-c6505e2bf474