Planet formation around M dwarfs via disc instability: Fragmentation conditions and protoplanet properties

Abstract

Context: Around 30 per cent of the observed exoplanets that orbit M dwarf stars are gas giants that are more massive than Jupiter. These planets are prime candidates for formation by disc instability. Aims: We want to determine the conditions for disc fragmentation around M dwarfs and the properties of the planets that are formed by disc instability. Methods: We performed hydrodynamic simulations of M dwarf protostellar discs in order to determine the minimum disc mass required for gravitational fragmentation to occur. Different stellar masses, disc radii, and metallicities were considered. The mass of each protostellar disc was steadily increased until the disc fragmented and a protoplanet was formed. Results: We find that a disc-to-star mass ratio between $\sim 0.3$ and $\sim 0.6$ is required for fragmentation to happen. The minimum mass at which a disc fragments increases with the stellar mass and the disc size. Metallicity does not significantly affect the minimum disc fragmentation mass but high metallicity may suppress fragmentation. Protoplanets form quickly (within a few thousand years) at distances around $\sim 50$ AU from the host star, and they are initially very hot; their centres have temperatures similar to the ones expected at the accretion shocks around planets formed by core accretion (up to 12,000K). The final properties of these planets (e.g. mass and orbital radius) are determined through long-term disc-planet or planet-planet interactions. Conclusions: Disc instability is a plausible way to form gas giant planets around M dwarfs provided that discs have at least 30% the mass of their host stars during the initial stages of their formation. Future observations of massive M dwarf discs or planets around very young M dwarfs are required to establish the importance of disc instability for planet formation around low-mass stars.

arXiv comment26 pages, A&A accepted

References in corpus (98)

• Galactic Stellar and Substellar Initial Mass Function
• On the variation of the Initial Mass Function
• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Disk Frequencies and Lifetimes in Young Clusters
• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• Nonlinear Outcome of Gravitational Instability in Cooling, Gaseous Disks
• Cosmological SPH simulations: The entropy equation
• Using FU Orionis Outbursts to Constrain Self-Regulated Protostellar Disk Models
• Rapid growth of gas-giant cores by pebble accretion
• The Mass Dependence Between Protoplanetary Disks and their Stellar Hosts
• Protoplanetary Disk Structures in Ophiuchus
• Defining and cataloging exoplanets: The exoplanet.eu database
• Gravitational Instabilities in Circumstellar Disks
• On the Luminosity of Young Jupiters
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Imaging Extrasolar Giant Planets
• The properties of brown dwarfs and low-mass hydrogen-burning stars formed by disc fragmentation
• Investigating fragmentation conditions in self-gravitating accretion discs
• Spiral Density Waves in a Young Protoplanetary Disk
• An ALMA Survey of Protoplanetary Disks in the $\sigma$ Orionis Cluster
• On the Role of Disks in the Formation of Stellar Systems: A Numerical Parameter Study of Rapid Accretion
• Characterization of exoplanets from their formation I: Models of combined planet formation and evolution
• Inviscid SPH
• The Runts of the Litter: Why planets formed through gravitational instability can only be failed binary stars
• The VLA Nascent Disk and Multiplicity Survey of Perseus Protostars (VANDAM). II. Multiplicity of Protostars in the Perseus Molecular Cloud
• On planet formation in HL Tau
• The CARMENES search for exoplanets around M dwarfs: High-resolution optical and near-infrared spectroscopy of 324 survey stars
• Challenges in Forming Planets by Gravitational Instability: Disk Irradiation and Clump Migration, Accretion & Tidal Destructio
• Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Protostellar Core Formation
• Why do protoplanetary disks appear not massive enough to form the known exoplanet population?
• Planets Around Low-Mass Stars (PALMS). IV. The Outer Architecture of M Dwarf Planetary Systems
• The Spitzer c2d Survey of Weak-line T Tauri Stars II: New Constraints on the Timescale for Planet Building
• Brown dwarf formation by gravitational fragmentation of massive, extended protostellar discs
• Nonlinear Outcome of Gravitational Instability in Disks with Realistic Cooling
• Formation of planets by tidal downsizing of giant planet embryos
• 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
• A Statistical Analysis of SEEDS and Other High-Contrast Exoplanet Surveys: Massive Planets or Low-Mass Brown Dwarfs?
• Formation of giant planets and brown dwarfs on wide orbits
• Numerical requirements for simulations of self gravitating and non-self gravitating disks
• Towards a Population Synthesis Model of Objects formed by Self-Gravitating Disc Fragmentation and Tidal Downsizing
• The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits. IV. Gravitational instability rarely forms wide, giant planets
• Planet-Planet Scattering Alone Cannot Explain the Free-Floating Planet Population
• A giant exoplanet orbiting a very low-mass star challenges planet formation models
• Protoplanetary Disk Masses from Stars to Brown Dwarfs
• The International Deep Planet Survey II: The frequency of directly imaged giant exoplanets with stellar mass
• Super-Earth masses sculpted by pebble isolation around stars of different masses
• A Definition for Giant Planets Based on the Mass-Density Relationship
• Substellar companions and isolated planetary mass objects from protostellar disc fragmentation
• The statistical properties of stars and their dependence on metallicity: the effects of opacity
• The dynamical evolution of multi-planet systems in open clusters
• Luminosity of young Jupiters revisited. Massive cores make hot planets
• Towards a population synthesis model of self-gravitating disc fragmentation and tidal downsizing II: The effect of fragment-fragment interactions
• Stability of Multiplanetary Systems in Star Clusters
• Introducing a Hybrid Method of Radiative Transfer for Smoothed Particle Hydrodynamics
• The role of thermodynamics in disc fragmentation
• Simulations of protostellar collapse using multigroup radiation hydrodynamics. II. The second collapse
• Formation, Orbital and Internal Evolutions of Young Planetary Systems
• On the reliability of protostellar disc mass measurements and the existence of fragmenting discs
• The HARPS search for southern extra-solar planets. XXXIV. A planetary system around the nearby M dwarf GJ163, with a super-Earth possibly in the habitable zone
• Have proto-planetary discs formed planets?
• The LEECH Exoplanet Imaging Survey: Limits on Planet Occurrence Rates Under Conservative Assumptions
• Effects of the Planetary Temperature on the Circumplanetary Disk and on the Gap
• Effects of radiation transfer on the structure of self-gravitating disks, their fragmentation and evolution of the fragments
• The properties of discs around planets and brown dwarfs as evidence for disc fragmentation
• Thermodynamics of Giant Planet Formation: Shocking Hot Surfaces on Circumplanetary Disks
• On the Mass Function, Multiplicity, and Origins of Wide-Orbit Giant Planets
• Dawes Review. The tidal downsizing hypothesis of planet formation
• Circumplanetary disks around young giant planets: a comparison between core-accretion and disk instability
• The Planetary Accretion Shock: I. Framework for Radiation-hydrodynamical Simulations and First Results
• Rapid Formation of Super-Earths around M Dwarf Stars
• The Planetary Accretion Shock. II. Grid of Post-Shock Entropies and Radiative Shock Efficiencies for Non-Equilibrium Radiation Transport
• The lower limits of disc fragmentation and the prospects for observing fragmenting discs
• MASSIVE: A Bayesian analysis of giant planet populations around low-mass stars
• Identifying and Analysing Protostellar Disc Fragments in Smoothed Particle Hydrodynamics Simulations
• The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits. III. The frequency of brown dwarfs and giant planets as companions to solar-type stars
• GANDALF - Graphical Astrophysics code for N-body Dynamics And Lagrangian Fluids
• The migration of gas giant planets in gravitationally unstable discs
• Observability of Forming Planets and their Circumplanetary Disks I. -- Parameter Study for ALMA
• Hot Super Earths: disrupted young jupiters?
• A grid of 1D low-mass star formation collapse models
• The effect of radiative feedback on disc fragmentation
• First Core Properties: From Low- to High-mass Star Formation
• On the diversity in mass and orbital radius of giant planets formed via disk instability
• High Contrast Imaging with Spitzer : Constraining the Frequency of Giant Planets out to 1000 AU separations
• Giant planets and brown dwarfs on wide orbits: a code comparison project
• The dynamical evolution of low-mass hydrogen-burning stars, brown dwarfs and planetary-mass objects formed through disc fragmentation
• Spiral-driven accretion in protoplanetary discs - II Self-similar solutions
• PSYM-WIDE: a survey for large-separation planetary-mass companions to late spectral type members of young moving groups
• The diverse lives of massive protoplanets in self-gravitating discs
• WEIRD: Wide-orbit Exoplanet search with InfraRed Direct imaging
• Constraining the initial planetary population in the gravitational instability model
• An Efficient Radiative Cooling Approximation for Use in Hydrodynamic Simulations
• Fragmentation of protoplanetary disks around M-dwarfs
• Efficient radiative transfer techniques in hydrodynamic simulations
• The long-term dynamical evolution of disc-fragmented multiple systems in the Solar Neighborhood
• On the origin of wide-orbit ALMA planets: giant protoplanets disrupted by their cores
• The structure of young embedded protostellar discs

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• DIPSY: A new Disc Instability Population SYnthesis, I. Modeling, evolution of individual systems, and tests
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• Planet migration in massive circumbinary discs