Computer Science – Numerical Analysis
Scientific paper
Apr 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994apj...424..688p&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 424, no. 2, p. 688-713
Computer Science
Numerical Analysis
25
Astronomical Models, Interstellar Gas, Interstellar Magnetic Fields, Magnetohydrodynamic Waves, Molecular Clouds, Stability, Star Clusters, Star Formation, Ambipolar Diffusion, Dispersions, Gravitation, Numerical Analysis, Velocity Distribution
Scientific paper
We investigate the local stability of massive molecular cloud cores that undergo cluster formation. We analyze these systems within the framework of a two-fluid model, namely, that of a magnetized molecular gas and a stellar young stellar object (YSO) fluid. These fluids are coupled by gravity and a prescribed star formation rate that converts the gas into stars on a timescale t* approx. = 0.5-5 Myr. Star formation only occurs in our model when the gas density rhog exceeds a critical density rhoc, as is suggested by the current observations. We identify a new form of instability that has no counterpart in the theory of single star formation in isolated, low mass cores. As such, it has important consequences for the evolution of cluster-forming cores. Newly formed YSOs within massive cores have velocity dispersions that are of the order of the clump-clump velocity dispersion of their parental minicores. This, however, is a factor of 3 or 4 smaller than the velocity dispersion of the magnetized gas comprising cluster cores. This stellar fluid is therefore much 'colder' than the magnetized gas and destabilizes the combined fluid. Thus, since the stellar fluid cannot be supported against collapse by the mean magnetic field or MHD waves in these cores, cluster-forming cores are destabilized by this process of 'stellar freeze-out.' We show that the instability acts much faster than the slow destabilization of the cluster gas by the leak of magnetic filed via ambipolar diffusion. Our process destabilizes such cores in several free-fall times tff, while ambipolar diffusion requires of order 10tff. We present detailed numerical solutions of this novel two-fluid instability and discuss its consequences for the physics of cluster formation.
Patel Kanan
Pudritz Ralph E.
No associations
LandOfFree
The formation of stellar groups and clusters in molecular cloud cores does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The formation of stellar groups and clusters in molecular cloud cores, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The formation of stellar groups and clusters in molecular cloud cores will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1255502