Simulation of primordial object formation

Abstract

We have included the chemical rate network responsible for the formation of molecular Hydrogen in the N-body hydrodynamic code, Hydra, in order to study the formation of the first cosmological at redshifts between 10 and 50. We have tested our implementation of the chemical and cooling processes by comparing N-body top hat simulations with theoretical predictions from a semi-analytic model and found them to be in good agreement. We find that post-virialization properties are insensitive to the initial abundance of molecular hydrogen. Our main objective was to determine the minimum mass ($M_{SG}(z)$) of perturbations that could become self gravitating (a prerequisite for star formation), and the redshift at which this occurred. We have developed a robust indicator for detecting the presence of a self-gravitating cloud in our simulations and find that we can do so with a baryonic particle mass-resolution of 40 solar masses. We have performed cosmological simulations of primordial objects and find that the object's mass and redshift at which they become self gravitating agree well with the $M_{SG}(z)$ results from the top hat simulations. Once a critical molecular hydrogen fractional abundance of about 0.0005 has formed in an object, the cooling time drops below the dynamical time at the centre of the cloud and the gas free falls in the dark matter potential wells, becoming self gravitating a dynamical time later.

45 pages, 17 figures, submitted to ApJ

References in corpus (3)

• Forming the First Stars in the Universe: The Fragmentation of Primordial Gas
• The Formation and Fragmentation of Primordial Molecular Clouds
• The Radiative Feedback of the First Cosmological Objects

Cited by in corpus (85)

• The Formation of the First Stars. I. The Primordial Star Forming Cloud
• The Assembly and Merging History of Supermassive Black Holes in Hierarchical Models of Galaxy Formation
• The First Stars
• Massive Black Holes as Population III Remnants
• Simulations of Early Structure Formation: Primordial Gas Clouds
• Simulations of Pregalactic Structure Formation with Radiative Feedback
• Formation of the First Stars by Accretion
• Formation of the First Stars
• The First Cosmic Structures and their Effects
• First Stars VIII -- Enrichment of the neutron-capture elements in the early Galaxy
• The Mass Spectrum of the First Stars
• Radiation Hydrodynamical Evolution of Primordial H II Regions
• The Universe Was Reionized Twice
• Primordial Star Formation under Far-ultraviolet radiation
• Early reionization by miniquasars
• The Structure and Evolution of Early Cosmological HII Regions
• Three Epochs of Star Formation in the High Redshift Universe
• Impact of the Relative Motion between the Dark Matter and Baryons on the First Stars
• Feedback from Galaxy Formation: Production and Photodissociation of Primordial Molecular Hydrogen
• Two populations of metal-free stars in the early Universe
• The Imprint of the Cosmic Dark Ages on the Near Infrared Background
• Molecular hydrogen, deuterium and metal abundances in the damped Ly-alpha system at z = 3.025 toward QSO 0347-3819
• Critical Metallicity and Fine-Structure Emission of Primordial Gas Enriched by the First Stars
• Effects of a Soft X-ray Background on Structure Formation at High Redshift
• The Stellar Initial Mass Function in Primordial Galaxies
• Suppression and Spatial Variation of Early Galaxies and Minihalos
• Formation of Dwarf Galaxies during the Cosmic Reionization
• The first generation of stars in LCDM cosmology
• Evolution of Very Massive Population III Stars with Mass Accretion from Pre-Main Sequence to Collapse
• Experimental Constraints on Self-consistent Reionization Models
• Radiative feedback from an early X-ray background
• Early structure in LCDM
• The First Miniquasar
• The Formation of the First Stars in the Universe
• The Number of Supernovae from Primordial Stars in the Universe
• Fragmentation and the formation of primordial protostars: the possible role of Collision Induced Emission
• The Influence of Streaming Velocities on the Formation of the First Stars
• Does Radiative Feedback by the First Stars Promote or Prevent Second Generation Star Formation?
• The mass of first stars
• Ionization Front Instabilities in Primordial H II Regions
• The First Stars in The Universe
• Radiation from the first forming stars
• The impact of dark matter decays and annihilations on the formation of the first structures
• Massive black hole remnants of the first stars in galactic haloes
• Merge or survive: Number of Population III stars per minihalo
• Where are the Low-Mass Population III Stars ?
• The formation and gas content of high redshift galaxies and minihalos
• Secondary Star Formation in a Population III Object
• Strong effects of time-dependent ionization in early SN 1987A
• Did Very Massive Stars Pre-enrich and Reionize the Universe?
• The Spatial Distribution of the Galactic First Stars II: SPH Approach
• Violence in the Dark Ages
• First Stars Contribution to the Near Infrared Background Fluctuations
• Cosmological Origin of the Lowest Metallicity Halo Stars
• Supersonic Relative Velocity between Dark Matter and Baryons: A Review
• Massive black hole remnants of the first stars I: abundance in present-day galactic haloes
• Cosmic Backgrounds from Miniquasars
• Origin of Two Distinct Populations in Dwarf Spheroidal Galaxies
• Starbursts in low-mass haloes at Cosmic Dawn. I. The critical halo mass for star formation
• Where are the sources of the Near Infrared Background?
• Supernova progenitors and iron density evolution from SN rate evolution measurements
• The micro-structure of the intergalactic medium I: the 21cm signature from dynamical minihaloes
• Radiative Regulation of Population III Star Formation
• Massive black hole remnants of the first stars III: observational signatures from the past
• An Observational Limit on the Earliest GRBs
• Cosmic Renaissance: The First Sources of Light
• Formation Criteria and the Mass of Secondary Population III Stars
• How big were the first cosmological objects?
• Is Primordial He Truly from Big Bang ?
• Amplification of turbulence in contracting prestellar cores in primordial minihalos
• Massive black hole remnants of the first stars II: optical and X-ray signatures in present-day galactic haloes
• On the Possibility of Observing H2 Emission from Primordial Molecular Cloud Kernels
• On the Possibility of Observing the Double Emission Line Feature of H${}_2$ and HD from Primordial Molecular Cloud Cores
• Feedback Effects of First Supernovae on the Neighboring Dark Matter Halos
• Modification of the halo mass function by kurtosis associated with primordial non-Gaussianity
• Amplification and saturation of turbulent magnetic field in collapsing primordial gas clouds
• Formation and Radiative Feedback of First Objects and First Galaxies
• Formation of mini-galaxies in defunct cosmological HII regions
• HD molecule and search for early structure-formation signatures in the Universe
• Saturation level of turbulence in collapsing gas clouds
• Constraining Dynamical Dark Energy Models through the Abundance of High-Redshift Supermassive Black Holes
• Formation and Evolution of Supermassive Black Holes
• The mass-function of primordial star clusters
• The Lowest Metallicity Stars in the LMC: Clues from MaGICC Simulations
• On the Formation Age of the First Planetary System