Disk fragmentation and the formation of population III stars

Abstract

Our understanding of population III star formation is still in its infancy. They are formed in dark matter minihalos of $10^5-10^6{\mathrm{M}}_{\odot }$ at $z=20-30$. Recent high resolution cosmological simulations show that a protostellar disk forms as a consequence of gravitational collapse and fragments into multiple clumps. However, it is not entirely clear if these clumps will be able to survive to form multiple stars as simulations are unable to follow the disk evolution for longer times. In this study, we employ a simple analytical model to derive the properties of marginally stable steady-state disks. Our results show that the stability of the disk depends on the critical value of the viscous parameter $\alpha$. For ${\alpha }_{crit}=1$, the disk is stable for an accretion rate of $\le 10^{-3}{\mathrm{M}}_{\odot }/yr$ and becomes unstable at radii about $\ge 100AU$ in the presence of an accretion rate of $10^{-2}{\mathrm{M}}_{\odot }/yr$. For $0.06<{\alpha }_{crit}<1$, the disk can be unstable for both accretion rates. The comparison of the migration and the Kelvin-Helmholtz time scales shows that clumps are expected to migrate inward before reaching the main sequence. Furthermore, in the presence of a massive central star the clumps within the central 1 AU will be tidally disrupted. We also find that UV feedback from the central star is unable to disrupt the disk, and that photo-evaporation becomes important only once the accretion rate has dropped to $2\times 10^{-4}{\mathrm{M}}_{\odot }/yr$. As a result, the central star may reach a mass of 100 ${\mathrm{M}}_{\odot }$ or even higher.

arXiv commentAccepted for publication in MNRAS, comments are still wlecome

References in corpus (31)

• The Formation of the First Star in the Universe
• The Formation of the First Stars. I. The Primordial Star Forming Cloud
• Nonlinear Outcome of Gravitational Instability in Cooling, Gaseous Disks
• On the properties of massive Population III stars and metal-free stellar populations
• One Hundred First Stars : Protostellar Evolution and the Final Masses
• The Formation and Fragmentation of Primordial Molecular Clouds
• Formation of Primordial Stars in a LCDM Universe
• The Formation and Fragmentation of Disks around Primordial Protostars
• Protostellar Feedback Halts the Growth of the First Stars in the Universe
• Protostar Formation in the Early Universe
• The Formation of Population III Binaries from Cosmological Initial Conditions
• Investigating fragmentation conditions in self-gravitating accretion discs
• Starbursts near supermassive black holes: young stars in the Galactic Center, and gravitational waves in LISA band
• Protostellar Collapse with Various Metallicities
• The Mass Spectrum of the First Stars
• The Formation of the First Stars II. Radiative Feedback Processes and Implications for the Initial Mass Function
• KROME - a package to embed chemistry in astrophysical simulations
• The First Stars: Mass Growth Under Protostellar Feedback
• Challenges in Forming Planets by Gravitational Instability: Disk Irradiation and Clump Migration, Accretion & Tidal Destructio
• Rapidly Accreting Supergiant Protostars: Embryos of Supermassive Black Holes?
• The characteristic black hole mass resulting from direct collapse in the early universe
• Massive black hole factories: Supermassive and quasi-star formation in primordial halos
• Fragmentation and the formation of primordial protostars: the possible role of Collision Induced Emission
• Does disk fragmentation prevent the formation of supermassive stars in protogalaxies?
• Reionization - A probe for the stellar population and the physics of the early universe
• Gravitational instability in protostellar disks at low metallicities
• The formation of massive Pop III stars in the presence of turbulence
• Photoevaporation of Circumstellar Disks Revisited: The Dust-Free Case
• Radiative cooling implementations in simulations of primordial star formation
• Cosmic Renaissance: The First Sources of Light
• Impact of an accurate modeling of primordial chemistry in high resolution studies

Cited by in corpus (27)

• Formation of supermassive black hole seeds
• Formation and survival of Population III stellar systems
• Formation of massive seed black holes via collisions and accretion
• Collisions in Primordial Star Clusters: Formation Pathway for intermediate mass black holes
• The Birth Mass Function of Pop III Stars
• The importance of magnetic fields for the initial mass function of the first stars
• Predicting the locations of possible long-lived low-mass first stars: Importance of satellite dwarf galaxies
• Witnessing the birth of a supermassive protostar
• Impact of dust cooling on direct collapse black hole formation
• Assessing inflow rates in atomic cooling halos: implications for direct collapse black holes
• Radiation Hydrodynamical Simulations of the Birth of Intermediate-Mass Black Holes in the First Galaxies
• Forming Pop III binaries in self-gravitating disks: how to keep the orbital angular momentum
• Magnetic fields in primordial accretion disks
• The effects of a background potential in star cluster evolution: a delay in the relaxation time-scale and runaway collision processes
• UV regulated star formation in high-redshift galaxies
• Stellar Tidal Disruption Events by Direct Collapse Black Holes
• Intermittent fragmentation and statistical variations during gas collapse in magnetised atomic cooling haloes
• Modeling gravitational instabilities in self-gravitating protoplanetary disks with adaptive mesh refinement techniques
• Formation of metal-free binaries: Impact of H${}_2$ line cooling and CIE cooling
• Does the chemothermal instability have any role in the fragmentation of primordial gas
• Do fragmentation and accretion affect the stellar Initial Mass Function?
• Modelling H${}_2$ and its effects on star formation using a joint implementation of GADGET-3 and KROME
• The chemical evolution of self-gravitating primordial disks
• Simulating the collapse of rotating primordial gas clouds to study the survival possibility of Pop III protostars
• Black hole formation via gas-dynamical processes
• When did the initial mass function become bottom-heavy?
• Off-center black hole seed formation? Implications for high and low redshift massive black holes