English
Related papers

Related papers: An empirical model for protostellar collapse

200 papers

We present 30 and 40 micron imaging of the massive protostar G35.20-0.74 with SOFIA-FORCAST. The high surface density of the natal core around the protostar leads to high extinction, even at these relatively long wavelengths, causing the…

Following an approach initially outlined by McKee & Holliman, we investigate the structure and stability of dense, starless molecular cloud cores. We model those as spherical clouds in hydrostatic equilibrium and supported against gravity…

Astrophysics · Physics 2007-05-23 J. Kauffmann , F. Bertoldi

The distribution of protostar masses is studied for core-environment systems whose duration of infall follows a waiting-time distribution. Each core-environment system has a continuous density profile with no barrier to mass flow. The core…

Astrophysics of Galaxies · Physics 2014-11-20 Philip C. Myers

The current generation of millimeter interferometers have revealed a population of compact (r <~ 0.1 pc), massive (M ~ 100 Msun) gas cores that are the likely progenitors of massive stars. I review models for the evolution of these objects…

Astrophysics · Physics 2007-05-23 Mark R. Krumholz

We develop a self-consistent model for the equilibrium gas temperature and size-dependent dust temperature in cold, dense pre-stellar cores, assuming an arbitrary power-law size distribution of dust grains. Compact analytical expressions…

Astrophysics of Galaxies · Physics 2019-11-06 Alexei V. Ivlev , Kedron Silsbee , Olli Sipilä , Paola Caselli

Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud…

Astrophysics · Physics 2007-05-23 Ralf Klessen

We have coupled a chemical model with two dynamical models of collapsing low mass star-forming cores to predict abundances across the core of the commonly used infall tracers, CS and HCO$^+$, at various stages of the collapse. The models…

Solar and Stellar Astrophysics · Physics 2015-05-19 Julia F. Roberts , Hugh A. W. Stace , Jonathan M. C. Rawlings

Protoplanetary disks are challenging objects for astrochemical models due to strong density and temperature gradients and due to the UV photons 2D propagation. In this paper, we have studied the importance of several model parameters on the…

Pre-stellar cores are the basic unit for the formation of stars and stellar systems. The anatomy of the physical and chemical structures of pre-stellar cores is critical for understanding the star formation process. L1544 is a prototypical…

Astrophysics of Galaxies · Physics 2022-09-21 Yuxin Lin , Silvia Spezzano , Olli Sipilä , Anton Vasyunin , Paola Caselli

Through the magnetic braking and the launching of protostellar outflows, magnetic fields play a major role in the regulation of angular momentum in star formation, which directly impacts the formation and evolution of protoplanetary disks…

Solar and Stellar Astrophysics · Physics 2020-09-04 Pierre Marchand , Kengo Tomida , Kei Tanaka , Benoît Commerçon , Gilles Chabrier

The first hydrostatic core, also called the first Larson core, is one of the first steps in low-mass star formation, as predicted by theory. With recent and future high performance telescopes, details of these first phases become…

Astrophysics of Galaxies · Physics 2016-05-04 U. Hincelin , B. Commercon , V. Wakelam , F. Hersant , S. Guilloteau , E. Herbst

We summarize the current status of the turbulent model of star formation in turbulent molecular clouds. In this model, clouds, clumps and cores form a hierarchy of nested density fluctuations caused by the turbulence, and either collapse or…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni

Radiative transfer models of multi-transition observations are used to determine molecular abundances as functions of position in pre- and protostellar cores. The data require a "drop" abundance profile with radius, with high abundances in…

Astrophysics · Physics 2009-11-10 J. K. Jorgensen , F. L. Schoeier , E. F. van Dishoeck

We perform fully general relativistic simulations of rotating stellar core collapse in three spatial dimension. A parametric equation of state is adopted following Dimmelmeier et al. The early stage of the collapse is followed by an…

Astrophysics · Physics 2008-11-26 Masaru Shibata , Yu-ichirou Sekiguchi

We aim at characterising dense cores in the clustered environments associated with massive star-forming regions. For this, we present an uniform analysis of VLA NH3(1,1) and (2,2) observations towards a sample of 15 massive star-forming…

Recent stellar evolutionary calculations of low-metallicity massive fast-rotating main-sequence stars yield iron cores at collapse endowed with high angular momentum. It is thought that high angular momentum and black hole formation are…

Astrophysics · Physics 2009-11-13 Luc Dessart , Adam Burrows , Eli Livne , Christian Ott

The physical and chemical properties of prestellar cores, especially massive ones, are still far from being well understood due to the lack of a large sample. The low dust temperature ($<$14 K) of Planck cold clumps makes them promising…

We test the hypothesis that the starless cores may be gravitationally bound clouds supported largely by thermal pressure by comparing observed molecular line spectra to theoretical spectra produced by a simulation that includes…

Astrophysics · Physics 2009-11-13 Eric Keto , George Field

The transport of angular momentum is capital during the formation of low-mass stars; too little removal and rotation ensures stellar densities are never reached, too much and the absence of rotation means no protoplanetary disks can form.…

Solar and Stellar Astrophysics · Physics 2018-07-04 Neil Vaytet , Benoît Commerçon , Jacques Masson , Matthias González , Gilles Chabrier

Star formation in magnetically subcritical clouds is investigated using a three-dimensional non-ideal magneto-hydrodynamics simulation. Since rapid cloud collapse is suppressed until the magnetic flux is sufficiently removed from the…

Solar and Stellar Astrophysics · Physics 2017-11-29 Masahiro N. Machida , Koki Higuchi , Satoshi Okuzumi
‹ Prev 1 8 9 10 Next ›