Variable Accretion Rates and Fluffy First Stars

Abstract

We combine the output of hydrodynamical simulations of Population III star cluster formation with stellar evolution models, and calculate the evolution of protostars experiencing variable mass accretion rates due to interactions within a massive disk. We find that the primordial protostars are extended 'fluffy' objects for the bulk of their pre-main-sequence lifetimes. Accretion luminosity feedback from such objects is high, but as shown in previous work, has a minimal effect on the star cluster. The extended radii of the protostars, combined with the observation of close encounters in the simulations, suggests that mergers will occur in such systems. Furthermore, mass transfer between close protostellar binaries with extended radii could lead to massive tight binaries, which are a possible progenitor of gamma ray bursts.

7 pages, 6 figures, 2 tables. To be published in MNRAS

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Cited by in corpus (42)

• Formation of the First Stars
• Building up the Population III initial mass function from cosmological initial conditions
• Formation of Massive Primordial Stars: Intermittent UV Feedback with Episodic Mass Accretion
• Titans of the Early Universe: The Prato Statement on the Origin of the First Supermassive Black Holes
• Rapidly Accreting Supergiant Protostars: Embryos of Supermassive Black Holes?
• Constraining the Statistics of Population III Binaries
• The characteristic black hole mass resulting from direct collapse in the early universe
• On the existence of accretion-driven bursts in massive star formation
• Massive black hole factories: Supermassive and quasi-star formation in primordial halos
• Formation of massive seed black holes via collisions and accretion
• Forming spectroscopic massive proto-binaries by disk fragmentation
• The Formation of Population III Stars in Gas Accretion Stage: Effects of Magnetic Fields
• The mass of first stars
• Formation of primordial supermassive stars by burst accretion
• Collisions in Primordial Star Clusters: Formation Pathway for intermediate mass black holes
• Formation sites of Population III star formation: The effects of different levels of rotation and turbulence on the fragmentation behavior of primordial gas
• The Birth Mass Function of Pop III Stars
• The First Stars: A Low-Mass Formation Mode
• Formation of the first stars and black holes
• Supermassive star formation via episodic accretion: protostellar disc instability and radiative feedback efficiency
• Thermal Feedback in the high-mass star and cluster forming region W51
• Multi-directional mass-accretion and collimated outflows in W51
• Protostellar Feedback and Final Mass of the Second-Generation Primordial Stars
• The formation of massive Pop III stars in the presence of turbulence
• Trapping of HII regions in Population III star formation
• The Burst Mode of Accretion in Primordial Protostars
• Accretion Phase of Star Formation in Clouds with Different Metallicities
• Lyman-Werner UV Escape Fractions from Primordial Halos
• WIMP DM and first stars: suppression of fragmentation in primordial star formation
• Formation of the first stars
• Dark Stars: Improved Models and First Pulsation Results
• The effects of a background potential in star cluster evolution: a delay in the relaxation time-scale and runaway collision processes
• Effects of turbulence and rotation on protostar formation as a precursor to seed black holes
• Formation and evolution of primordial protostellar systems
• HII region variability and pre-main-sequence evolution
• Searching for Inflow Towards Massive Starless Clump Candidates Identified in the Bolocam Galactic Plane Survey
• On the Role of the $\Omega \Gamma$ Limit in the Formation of Population III Massive Stars
• Evolutionary tracks of massive stars during formation
• Primordial protostars accreting beyond the $\Omega \Gamma$-limit: radiation effect around the star-disk boundary
• Outflow-Confined HII regions. II. The Early Break-Out Phase
• The Luminosity of Population III Star Clusters
• Radiative feedback on supermassive star formation: the massive end of the Population III initial mass function