Protostar Mass Due to Infall and Dispersal

Abstract

The mass of a protostar is calculated from the infall and dispersal of an isothermal sphere in a uniform background. For high contrast between peak and background densities and for short dispersal time t_d, the accretion is "self-limiting": gas beyond the core is dispersed before it accretes, and the protostar mass approaches a time-independent value of low mass. For lower density contrast and longer dispersal time, the accretion "runs away": gas accretes from beyond the core, and the protostar mass approaches massive star values. The final protostar mass is approximately the initial gas mass whose free-fall time equals t_d. This mass matches the peak of the IMF for gas temperature 10 K, peak and background densities 10^6 and 10^3 cm^-3, and for t_d comparable to the core free-fall time t_core. The accretion luminosity exceeds 1 L-Sun for 0.1 Myr, as in the "Class 0" phase. For t_d/t_core=0.4-0.8 and temperature 7-50 K, self-limiting protostar masses are 0.08-5 M-Sun. These protostar and core masses have ratio 0.4 +- 0.2, as expected if the core mass distribution and the IMF have the same shape.

60 pages, 8 figures, accepted by Astrophysical Journal

References in corpus (45)

• Embedded Clusters in Molecular Clouds
• Theory of Star Formation
• The Initial Mass Function of Stars: Evidence for Uniformity in Variable Systems
• Control of star formation by supersonic turbulence
• Toward Understanding Massive Star Formation
• Cold Dark Clouds: The Initial Conditions for Star Formation
• The Formation of Brown Dwarfs as Ejected Stellar Embryos
• Analytical theory for the initial mass function: CO clumps and prestellar cores
• The mass function of dense molecular cores and the origin of the IMF
• Probing the evolutionary status of starless cores through N2H+ and N2D+ observations
• Tracing the Mass during Low-Mass Star Formation. II. Modelling the Submillimeter Emission from Pre-Protostellar Cores
• Efficiencies of Low-Mass Star and Star Cluster Formation
• The Physics of Star Formation
• The initial mass function : from Salpeter 1955 to 2005
• Bolocam Survey for 1.1 mm Dust Continuum Emission in the c2d Legacy Clouds. I. Perseus
• Planet Formation by Coagulation: A Focus on Uranus and Neptune
• Observing the gas temperature drop in the high-density nucleus of L 1544
• The Evolution of Outflow-Envelope Interactions in Low-Mass Protostars
• A Theory of the IMF for Star Formation in Molecular Clouds
• The Origin of Episodic Accretion Bursts in the Early Stages of Star Formation
• Early Evolution of Stellar Groups and Clusters: Environmental Effects on Forming Planetary Systems
• Bolocam Survey for 1.1 mm Dust Continuum Emission in the c2d Legacy Clouds. II. Ophiuchus
• The Nature of the Dense Core Population in the Pipe Nebula: Thermal Cores Under Pressure
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• An Ammonia Spectral Atlas of Dense Cores in Perseus
• A Survey for Infall Motions toward Starless Cores. I. CS (2-1) and N${}_2$H${}^{+}$ (1-0) Observations
• On the internal structure of starless cores. II. A molecular survey of L1498 and L1517B
• Comparing Star Formation on Large Scales in the c2d Legacy Clouds: Bolocam 1.1 mm Dust Continuum Surveys of Serpens, Perseus, and Ophiuchus
• The Spitzer c2d Survey of Large, Nearby, Insterstellar Clouds. IX. The Serpens YSO Population As Observed With IRAC and MIPS
• Formation of massive stars by growing accretion rate
• Near Infrared Imaging Survey of Bok Globules: Density Structure
• An unbiased search for the signatures of protostars in the rho Ophiuchi Molecular Cloud. II. Millimetre continuum observations
• Collapse-Driven Outflow in Star-Forming Molecular Cores
• Current Star Formation in the Ophiuchus and Perseus Molecular Clouds: Constraints and Comparisons from Unbiased Submillimeter and Mid-Infrared Surveys. II
• Current Star Formation in the Perseus Molecular Cloud: Constraints from Unbiased Submillimeter and Mid-Infrared Surveys
• A Model for the Internal Structure of Molecular Cloud Cores
• Does Magnetic Levitation or Suspension Define the Masses of Forming Stars?
• Magnetically Controlled Spasmodic Accretion During Star Formation. II. Results
• Generalized Collapse Solutions with Nonzero Initial Velocities for Star Formation in Molecular Cloud Cores
• Centrally Condensed Collapse of Starless Cores
• The Photoionization of a Star-Forming Core in the Trifid Nebula
• Carina's Defiant Finger: HST Observations of a Photoevaporating Globule in NGC3372
• An analytic approximation to the isothermal sphere
• Ambipolar Diffusion in Molecular Cloud Cores and the Gravomagneto Catastrophe
• Generation of density inhomogeneities by magnetohydrodynamic waves in two dimensions

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• PROSAC: A Submillimeter Array survey of low-mass protostars. II. The mass evolution of envelopes, disks, and stars from the Class 0 through I stages
• A Correlation Between Surface Densities of Young Stellar Objects and Gas in Eight Nearby Molecular Clouds
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• ALMA Observations of the HH 46/47 Molecular Outflow
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• ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow: Structure, Entrainment and Core Impact
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• Lowering the Characteristic Mass of Cluster Stars by Magnetic Fields and Outflow Feedback
• Far-infrared Observations of the Very Low-Luminosity Embedded Source L1521F-IRS in the Taurus Star-Forming Region
• The IMF and multiplicity of stars from gravity, turbulence, magnetic fields, radiation and outflow feedback
• A quantification of the non-spherical geometry and accretion of collapsing cores
• On the distribution of protostar masses
• Isotropically Driven versus Outflow Driven Turbulence: Observational Consequences for Molecular Clouds
• Star formation in dense clusters
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• The Evolution of Protostellar Outflow Cavities, Kinematics, and Angular Distribution of Momentum and Energy in Orion A: Evidence for Dynamical Cores
• The role of the turbulence driving mode for the Initial Mass Function
• What does a universal IMF imply about star formation?
• On the role of ambient environments in the collapse of Bonnor-Ebert spheres
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• The physics and modes of star cluster formation: simulations
• Application of Convolutional Neural Networks to Identify Protostellar Outflows in CO Emission
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• On the mass function of stars growing in a flocculent medium
• Can Protostellar Outflows Set Stellar Masses?
• CSO CO(2-1) and Spitzer IRAC Observations of a Bipolar Outflow in High-mass Star-forming Region IRAS 22506+5944
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