Empirical formulae to describe some physical properties of small groups of protogalaxies with multiplicity

Abstract

By means of identical cubic elements, we generate a partition of a volume in which a particle-based cosmological simulation is carried out. In each cubic element, we determine the gas particles with a normalized density greater than an arbitrarily chosen density threshold. By using a proximity parameter, we calculate the neighboring cubic elements and generate a list of neighbors. By imposing dynamic conditions on the gas particles, we identify gas clumps and their neighbors, so that we calculate and fit some properties of the groups so identified, including the mass, size and velocity dispersion, in terms of their multiplicity (here defined simply as the number of member galaxies). Finally, we report the value of the ratio of kinetic energy to gravitational energy of such dense gas clumps, which will be useful as initial conditions in simulations of gravitational collapse of gas clouds and clusters of gas clouds.

arXiv commentAccepted for publication in Research in Astronomy and Astrophysics

References in corpus (38)

• The Sloan Digital Sky Survey: Technical Summary
• The cosmological simulation code GADGET-2
• Properties of galaxies reproduced by a hydrodynamic simulation
• The Fourth Data Release of the Sloan Digital Sky Survey
• The Stellar IMF from Turbulent Fragmentation
• Cold Dark Clouds: The Initial Conditions for Star Formation
• Galaxy Groups in the SDSS DR4: I. The Catalogue and Basic Properties
• Power Spectra for Cold Dark Matter and its Variants
• The Formation of a Star Cluster: Predicting the Properties of Stars and Brown Dwarfs
• Dense Cores in Dark Clouds. XIV. N2H+(1-0) maps of dense cloud cores
• Competitive accretion in embedded stellar cluster
• Analytical theory for the initial mass function: CO clumps and prestellar cores
• Planck 2013 results. XXIX. Planck catalogue of Sunyaev-Zeldovich sources
• The 2dF Galaxy Redshift Survey: The b_J-band galaxy luminosity function and survey selection function
• HOP: A New Group-Finding Algorithm for N-body Simulations
• Haloes gone MAD: The Halo-Finder Comparison Project
• Galaxy groups in the 2dFGRS: the group-finding algorithm and the 2PIGG catalogue
• Percolation Galaxy Groups and Clusters in the SDSS Redshift Survey: Identification, Catalogs, and the Multiplicity Function
• Accretion-Driven Turbulence as Universal Process: Galaxies, Molecular Clouds, and Protostellar Disks
• Low Virial Parameters in Molecular Clouds: Implications for High Mass Star Formation and Magnetic Fields
• The Formation of Stellar Clusters: Gaussian Cloud Conditions I
• The Exciting Lives of Giant Molecular Clouds
• The Stellar IMF, Core Mass Function, & The Last-Crossing Distribution
• Analytical theory for the initial mass function: II. Properties of the flow
• The Formation of Stellar Clusters: Gaussian Initial Conditions II
• Satellites of Simulated Galaxies: survival, merging, and their relation to the dark and stellar halos
• The Cross-Correlation between Galaxies and Groups: Probing the Galaxy Distribution in and around Dark Matter Haloes
• Clump Lifetimes and the Initial Mass Function
• On the luminosity function of galaxies in groups in the Sloan Digital Sky Survey
• The 2dF Galaxy Redshift Survey: The clustering of galaxy groups
• Introducing a new, robust galaxy finder algorithm for simulations
• Clusters and groups of galaxies in the 2dF galaxy redshift survey
• Groups of galaxies: relationship between environment and galaxy properties
• On the Origin of the Salpeter Slope for the Initial Mass Function
• GARROTXA Cosmological Simulations of Milky Way-sized Galaxies: General Properties, Hot Gas Distribution, and Missing Baryons
• Comparing binary systems from rotating parent gas structures with different total masses
• G337.342-0.119 (the "Pebble"): A Cold, Dense, High-Mass Molecular Cloud with Unusually Large Linewidths and a Candidate High-Mass Star Cluster Progenitor
• The extreme initial kinetic energy allowed by a collapsing turbulent core