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Related papers: The Effect of Magnetic Fields and Ambipolar Diffus…

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In a previous paper we formulated the problem of the formation and evolution of fragments (or cores) in magnetically-supported, self-gravitating molecular clouds in axisymmetric geometry, accounting for the effects of ambipolar diffusion…

Solar and Stellar Astrophysics · Physics 2015-05-18 M. W. Kunz , T. Ch. Mouschovias

We clarify the mechanism of accelerated core formation by large-scale nonlinear flows in subcritical magnetic clouds by finding a semi-analytical formula for the core formation time and describing the physical processes that lead to them.…

Solar and Stellar Astrophysics · Physics 2015-06-22 Takahiro Kudoh , Shantanu Basu

The mass distribution of prestellar cores is obtained for clouds with arbitrary internal mass distributions using a selection criterion based on the thermal and turbulent Jeans mass and applied hierarchically from small to large scales. We…

Solar and Stellar Astrophysics · Physics 2012-08-02 Antonio Parravano , Nestor Sanchez , Emilio J. Alfaro

Using recently established empirical calibrations for the impact of chromospheric activity on the radii, effective temperatures, and estimated masses of active low-mass stars and brown dwarfs, we reassess the shape of the initial mass…

Solar and Stellar Astrophysics · Physics 2015-06-23 Keivan G. Stassun , Aleks Scholz , Trent Dupuy , Kaitlin Kratter

We present first results of our simulations of magnetic fields in the formation of single and binary stars using a recently developed method for incorporating Magnetohydrodynamics (MHD) into the Smoothed Particle Hydrodynamics (SPH) method.…

Astrophysics · Physics 2009-06-23 Daniel J. Price , Matthew R. Bate

In a magnetically-dominated model of star formation, we expect to see alignments between the magnetic field orientation of star-forming dense cores and the cloud-scale magnetic field. Pandhi et al. (2023) showed instead, however, that the…

The manner in which the stellar initial mass function (IMF) scales with global galaxy properties is under debate. We use two hydrodynamical, cosmological simulations to predict possible trends for two self-consistent variable IMF…

Astrophysics of Galaxies · Physics 2018-10-22 Christopher Barber , Joop Schaye , Robert A. Crain

Stars are born in dense cores of molecular clouds. The core mass function (CMF), which is the mass distribution of dense cores, is important for understanding the stellar initial mass function (IMF). We obtained 350 $\mu$m dust continuum…

Solar and Stellar Astrophysics · Physics 2014-04-10 Guoyin Zhang , Di Li , Ashley K. Hyde , Lei Qian , Hualei Lyu , Zhongzu Wu

The regulation of galactic-scale star formation rates (SFRs) is a basic problem for theories of galaxy formation and evolution: which processes are responsible for making observed star formation rates so inefficient compared to maximal…

Astrophysics of Galaxies · Physics 2015-06-23 Sven Van Loo , Jonathan C. Tan , Sam A. E. G. Falle

In early-type stars a fossil magnetic field may be generated during the star formation process or be the result of a stellar merger event. Surface magnetic fields are thought to be erased by (sub)surface convection layers, which typically…

Solar and Stellar Astrophysics · Physics 2020-06-17 Adam S. Jermyn , Matteo Cantiello

Observations suggest that star formation in filamentary molecular clouds occurs in a two-step process, with the formation of filaments preceding that of prestellar cores and stars. Here, we apply the gravo-turbulent fragmentation theory of…

Astrophysics of Galaxies · Physics 2017-10-04 Yueh-Ning Lee , Patrick Hennebelle , Gilles Chabrier

We study the mass-to-flux ratio (M/\Phi) of clumps and cores in simulations of supersonic, magnetohydrodynamical turbulence for different initial magnetic field strengths. We investigate whether the (M/\Phi)-ratio of core and envelope, R =…

Solar and Stellar Astrophysics · Physics 2015-06-03 Erik Bertram , Christoph Federrath , Robi Banerjee , Ralf S. Klessen

The Zeeman effect and dust grain alignment are two major methods for probing magnetic fields (B-fields) in molecular clouds, largely motivated by the study of star formation, as the B-field may regulate gravitational contraction and channel…

Astrophysics of Galaxies · Physics 2021-06-16 Hua-bai Li

We report here observations of the Zeeman effect in the 18-cm lines of OH in the envelope regions surrounding four molecular cloud cores toward which detections of B(LOS) have been achieved in the same lines, and evaluate the ratio of mass…

Astrophysics · Physics 2011-02-11 Richard M. Crutcher , Nicholas Hakobian , Thomas H. Troland

Observations indicate that the central portions of the Present-Day Prestellar Core Mass Function (CMF) and the Stellar Initial Mass Function (IMF) both have approximately log-normal shapes, but that the CMF is displaced to higher mass than…

Solar and Stellar Astrophysics · Physics 2013-06-07 K. Holman , S. K. Walch , S. P. Goodwin , A. P. Whitworth

The stellar initial mass function (IMF) is critical to our understanding of star formation and the effects of young stars on their environment. On large scales, it enables us to use tracers such as UV or Halpha emission to estimate the star…

We review the properties of low mass dense molecular cloud cores, including starless, prestellar, and Class 0 protostellar cores, as derived from observations. In particular we discuss them in the context of the current debate surrounding…

Astrophysics · Physics 2007-05-23 D. Ward-Thompson , P. Andre , R. Crutcher , D. Johnstone , T. Onishi , C. Wilson

We study effect of magnetic field on massive dense core formation in colliding unequal molecular clouds by performing magnetohydrodynamic simulations with sub-parsec resolution (0.015 pc) that can resolve the molecular cores. Initial clouds…

Astrophysics of Galaxies · Physics 2020-07-23 Nirmit Sakre , Asao Habe , Alex R. Pettitt , Takashi Okamoto

Magnetic fields are observed in star forming regions. However simulations of the late stages of star formation that do not include magnetic fields provide a good fit to the properties of young stars including the initial mass function (IMF)…

Solar and Stellar Astrophysics · Physics 2018-10-17 C. J. Nixon , J. E. Pringle

The stellar mass spectrum is an important property of the stellar cluster and a fundamental quantity to understand our Universe. The fragmentation of diffuse molecular cloud into stars is subject to physical processes such as gravity,…

Astrophysics of Galaxies · Physics 2019-02-13 Yueh-Ning Lee , Patrick Hennebelle