Scale‐free Equilibria of Isopedic Polytropic Clouds
Open Access
- 20 August 1999
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 521 (2) , 630-639
- https://doi.org/10.1086/307579
Abstract
We investigate the equilibrium properties of self-gravitating magnetized clouds with polytropic equations of state with negative index n. In particular, we consider scale-free isopedic configurations that have constant dimensionless spherical mass-to-flux ratio λr and that may constitute "pivotal" states for subsequent dynamical collapse to form groups or clusters of stars. For given Γ = 1 + 1/n, equilibria with smaller values of λr are more flattened, ranging from spherical configurations with λr = ∞ to completely flattened states for λr = 1. For a given amount of support provided by the magnetic field as measured by the dimensionless parameter H0, equilibria with smaller values of Γ are more flattened. However, logatropic (defined by Γ = 0) disks do not exist. The only possible scale-free isopedic equilibria with logatropic equation of state are spherical uniformly magnetized clouds.Keywords
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This publication has 45 references indexed in Scilit:
- Coherent Dense Cores. I. NH3ObservationsThe Astrophysical Journal, 1998
- Dynamical Collapse of Nonrotating Magnetic Molecular Cloud Cores: Evolution through Point‐Mass FormationThe Astrophysical Journal, 1998
- Self-gravitating disc-like magnetic gas cloudsMonthly Notices of the Royal Astronomical Society, 1996
- The Line Width--Size Relation in Massive Cloud CoresThe Astrophysical Journal, 1995
- Magnetic braking, ambipolar diffusion, and the formation of cloud cores and protostars. 1: Axisymmetric solutionsThe Astrophysical Journal, 1994
- Ambipolar diffusion, interstellar dust, and the formation of cloud cores and protostars. 3: Typical axisymmetric solutionsThe Astrophysical Journal, 1994
- Pressure-confined clumps in magnetized molecular cloudsThe Astrophysical Journal, 1992
- The largest molecular cloud complexes in the first galactic quadrantThe Astrophysical Journal, 1986
- Unsteady hydrodynamics of spherical gravitational collapseThe Astrophysical Journal, 1978
- ON FORCE-FREE MAGNETIC FIELDSProceedings of the National Academy of Sciences, 1956