A connection between the rate of rotation of interstellar clouds, magnetic fields, ambipolar diffusion, and the periods of binary stars

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154912· OSTI ID:7130644

Mouschovias, T C

Observations do not show any interstellar clouds rotating much faster than the Galaxy. This can be attributed to magnetic braking, which the observed parameters of the interstellar medium show to be very efficient as long as the magnetic field is frozen in the matter. The critical density n/sub cr/ at which the field decouples from the matter determines the period of rotation of a binary star system, assumed to form by a collapsing (nearly nonmagnetic) fragment that conserves its angular momentum. The observed periods tau/sub b/ of binary stars (roughly 100 yr > or approx. = tau/sub b/> or approx. = 10 hr) may be accounted for if n/sub cr/ ranges from 7.5 x 10/sup 3/ cm/sup -3/ to 2.2 x 10/sup 6/ cm/sup -3/, respectively. We reexamine the process of ambipolar diffusion (by appropriately scaling the field strength to dense-cloud densities) and show that, at the above densities, it can decouple the field from the matter within 8.8 x 10/sup 5/ to 3.9 x 10/sup 7/ years. A scenario for star formation is outlined. (AIP)

• Research Organization: Department of Astrophysical Sciences, Princeton University
• OSTI ID: 7130644
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 211:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102 -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMBIPOLAR DIFFUSION
ANGULAR MOMENTUM
ANGULAR VELOCITY
BINARY STARS
COSMIC GASES
COSMIC RADIO SOURCES
DIFFUSION
FLUIDS
GASES
H1 REGIONS
INTERSTELLAR MAGNETIC FIELDS
INTERSTELLAR SPACE
MAGNETIC FIELDS
MOTION
ROTATION
SPACE
STAR ACCRETION
STAR EVOLUTION
STARS
VELOCITY