skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Resolving the Formation of Protogalaxies. II.Central Gravitational Collapse

Abstract

Numerous cosmological hydrodynamic studies have addressed the formation of galaxies. Here we choose to study the first stages of galaxy formation, including non-equilibrium atomic primordial gas cooling, gravity and hydrodynamics. Using initial conditions appropriate for the concordance cosmological model of structure formation, we perform two adaptive mesh refinement simulations of {approx} 10{sup 8} M{sub {circle_dot}} galaxies at high redshift. The calculations resolve the Jeans length at all times with more than 16 cells and capture over 14 orders of magnitude in length scales. In both cases, the dense, 10{sup 5} solar mass, one parsec central regions are found to contract rapidly and have turbulent Mach numbers up to 4. Despite the ever decreasing Jeans length of the isothermal gas, we only find one site of fragmentation during the collapse. However, rotational secular bar instabilities transport angular momentum outwards in the central parsec as the gas continues to collapse and lead to multiple nested unstable fragments with decreasing masses down to sub-Jupiter mass scales. Although these numerical experiments neglect star formation and feedback, they clearly highlight the physics of turbulence in gravitationally collapsing gas. The angular momentum segregation seen in our calculations plays an important role in theories that form supermassivemore » black holes from gaseous collapse.« less

Authors:
; ;
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
918012
Report Number(s):
SLAC-PUB-12883
Journal ID: ISSN 0004-637X; ASJOAB; arXiv:0710.1678; TRN: US200817%%1078
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Name: Astrophysical Journal; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANGULAR MOMENTUM; BLACK HOLES; COSMOLOGICAL MODELS; GAS COOLING; GRAVITATIONAL COLLAPSE; MACH NUMBER; GALAXIES; Astrophysics,ASTRO

Citation Formats

Wise, John H, Turk, Matthew J, and Abel, Tom. Resolving the Formation of Protogalaxies. II.Central Gravitational Collapse. United States: N. p., 2007. Web. doi:10.1086/520036.
Wise, John H, Turk, Matthew J, & Abel, Tom. Resolving the Formation of Protogalaxies. II.Central Gravitational Collapse. United States. https://doi.org/10.1086/520036
Wise, John H, Turk, Matthew J, and Abel, Tom. 2007. "Resolving the Formation of Protogalaxies. II.Central Gravitational Collapse". United States. https://doi.org/10.1086/520036. https://www.osti.gov/servlets/purl/918012.
@article{osti_918012,
title = {Resolving the Formation of Protogalaxies. II.Central Gravitational Collapse},
author = {Wise, John H and Turk, Matthew J and Abel, Tom},
abstractNote = {Numerous cosmological hydrodynamic studies have addressed the formation of galaxies. Here we choose to study the first stages of galaxy formation, including non-equilibrium atomic primordial gas cooling, gravity and hydrodynamics. Using initial conditions appropriate for the concordance cosmological model of structure formation, we perform two adaptive mesh refinement simulations of {approx} 10{sup 8} M{sub {circle_dot}} galaxies at high redshift. The calculations resolve the Jeans length at all times with more than 16 cells and capture over 14 orders of magnitude in length scales. In both cases, the dense, 10{sup 5} solar mass, one parsec central regions are found to contract rapidly and have turbulent Mach numbers up to 4. Despite the ever decreasing Jeans length of the isothermal gas, we only find one site of fragmentation during the collapse. However, rotational secular bar instabilities transport angular momentum outwards in the central parsec as the gas continues to collapse and lead to multiple nested unstable fragments with decreasing masses down to sub-Jupiter mass scales. Although these numerical experiments neglect star formation and feedback, they clearly highlight the physics of turbulence in gravitationally collapsing gas. The angular momentum segregation seen in our calculations plays an important role in theories that form supermassive black holes from gaseous collapse.},
doi = {10.1086/520036},
url = {https://www.osti.gov/biblio/918012}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = ,
volume = ,
place = {United States},
year = {Mon Oct 15 00:00:00 EDT 2007},
month = {Mon Oct 15 00:00:00 EDT 2007}
}