The Jeans Mass as a Fundamental Measure of Self-Gravitating Disc Fragmentation and Initial Fragment Mass

Abstract

As a formation route for objects such as giant planets and low-mass stars in protostellar discs (as well as stars in AGN discs), theories of self-gravitating disc fragmentation need to be able to predict the initial masses of fragments. We describe a means by which the local Jeans mass inside the spiral structure of a self-gravitating disc can be estimated. If such a self-gravitating disc satisfies the criteria for disc fragmentation, this estimate provides a lower limit for the initial mass of any fragments formed. We apply this approach to a series of self-gravitating protostellar disc models, to map out the typical masses of fragments produced by this formation mode. We find a minimum fragment mass of around 3 Jupiter masses, which is insensitive to the stellar mass, and that - within the parameter space surveyed - fragments with masses between 10 and 20 Jupiter masses are the most common. We also describe how the Jeans mass allows us to derive a more general criterion for disc fragmentation, which accounts for the processes of viscous heating, radiative cooling, accretion and the disc's thermal history. We demonstrate how such a criterion can be determined, and show that in limiting cases it recovers several fragmentation criteria that have been posited in the past, including the minimum cooling time/maximum stress criterion.

12 pages, 4 figures, accepted for publication in MNRAS

References in corpus (18)

• Starbursts near supermassive black holes: young stars in the Galactic Center, and gravitational waves in LISA band
• A Submillimeter View of Circumstellar Dust Disks in $\rho$ Ophiuchus
• The Two Modes of Gas Giant Planet Formation
• Characterising the Gravitational Instability in Cooling Accretion Discs
• Simulations of star formation in a gaseous disc around sgr A* - a failed AGN
• Star Formation Around Super-Massive Black Holes
• The Thermal Regulation of Gravitational Instabilities in Protoplanetary Disks III. Simulations with Radiative Cooling and Realistic Opacities
• The minimum mass for star formation, and the origin of binary brown dwarfs
• Radiative transfer and the energy equation in SPH simulations of star formation
• Can giant planets form by gravitational fragmentation of discs?
• Numerical requirements for simulations of self gravitating and non-self gravitating disks
• Core Formation in Giant Gaseous Protoplanets
• Tidally induced brown dwarf and planet formation in circumstellar discs
• Fragmentation of Shocked Flows: Gravity, Turbulence and Cooling
• Introducing a Hybrid Method of Radiative Transfer for Smoothed Particle Hydrodynamics
• The Thermal Regulation of Gravitational Instabilities in Protoplanetary Disks. IV. Simulations with Envelope Irradiation
• The response of self-graviting protostellar discs to slow reduction in cooling timescale: the fragmentation boundary revisited
• The role of the energy equation in the fragmentation of protostellar discs during stellar encounters

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• Changes in the metallicity of gas giant planets due to pebble accretion
• Binary companions triggering fragmentation in self-gravitating discs
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• The diverse lives of massive protoplanets in self-gravitating discs
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• Molecular tracers of planet formation in the atmospheres of hot Jupiters
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• Exploring the planetary-mass population in the Upper Scorpius association
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• The link between infall location, early disc size, and the fraction of self-gravitationally fragmenting discs
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