Publication:
Cosmological simulations with scale-free initial conditions. I. Adiabatic hydrodynamics

Simple item page
dc.contributor.authorOwen, JM
dc.contributor.authorWeinberg, DH
dc.contributor.authorEvrard, AE
dc.contributor.authorHernquist, L
dc.contributor.authorKatz, N
dc.contributor.departmentUniversity of Massachusetts - Amherst
dc.date2023-09-22T23:46:29.000
dc.date.accessioned2024-04-26T08:27:54Z
dc.date.available2024-04-26T08:27:54Z
dc.date.issued1998
dc.description<p>This is the pre-published version harvested from ArXiv. The published version is located at <a href="http://iopscience.iop.org/0004-637X/503/1/16/">http://iopscience.iop.org/0004-637X/503/1/16/</a></p>
dc.description.abstractWe analyze hierarchical structure formation based on scale-free initial conditions in an Einstein-de Sitter universe, including a baryonic component with Ωbary = 0.05. We present three independent, smoothed particle hydrodynamics (SPH) simulations, performed at two resolutions (323 and 643 dark matter and baryonic particles) and with two different SPH codes (TreeSPH and P3MSPH). Each simulation is based on identical initial conditions, which consist of Gaussian-distributed initial density fluctuations that have a power spectrum P(k) k-1. The baryonic material is modeled as an ideal gas subject only to shock heating and adiabatic heating and cooling; radiative cooling and photoionization heating are not included. The evolution is expected to be self-similar in time, and under certain restrictions we identify the expected scalings for many properties of the distribution of collapsed objects in all three realizations. The distributions of dark matter masses, baryon masses, and mass- and emission-weighted temperatures scale quite reliably. However, the density estimates in the central regions of these structures are determined by the degree of numerical resolution. As a result, mean gas densities and Bremsstrahlung luminosities obey the expected scalings only when calculated within a limited dynamic range in density contrast. The temperatures and luminosities of the groups show tight correlations with the baryon masses, which we find can be well represented by power laws. The Press-Schechter (PS) approximation predicts the distribution of group dark matter and baryon masses fairly well, though it tends to overestimate the baryon masses. Combining the PS mass distribution with the measured relations for T(M) and L(M) predicts the temperature and luminosity distributions fairly accurately, though there are some discrepancies at high temperatures/luminosities. In general the three simulations agree well for the properties of resolved groups, where a group is considered resolved if it contains more than 32 particles.
dc.description.pages16-36
dc.identifier.doihttps://doi.org/10.1086/305957
dc.identifier.urihttps://hdl.handle.net/20.500.14394/3031
dc.relation.ispartofASTROPHYSICAL JOURNAL
dc.relation.urlhttps://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1363&amp;context=astro_faculty_pubs&amp;unstamped=1
dc.source.issue1
dc.source.issue503
dc.source.statuspublished
dc.subjectcosmology : theory
dc.subjecthydrodynamics
dc.subjectlarge-scale structure of universe
dc.subjectmethods : numerical
dc.subjectAstrophysics and Astronomy
dc.titleCosmological simulations with scale-free initial conditions. I. Adiabatic hydrodynamics
dc.typearticle
dc.typearticle
digcom.contributor.authorOwen, JM
digcom.contributor.authorWeinberg, DH
digcom.contributor.authorEvrard, AE
digcom.contributor.authorHernquist, L
digcom.contributor.authorisAuthorOfPublication|email:nsk@astro.umass.edu|institution:University of Massachusetts - Amherst|Katz, N
digcom.identifierastro_faculty_pubs/364
digcom.identifier.contextkey1683052
digcom.identifier.submissionpathastro_faculty_pubs/364
dspace.entity.typePublication
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Cosmological_Simulations_with_Scale_Free_Initial_Conditions_I_Adiabatic.pdf
Size:
1.01 MB
Format:
Adobe Portable Document Format
Thumbnail Image
Name: Cosmological_Simulations_with_Scale_Free_Initial_Conditions_I_Adiabatic.pdf
Size: 1.01 MB
Kind: Adobe PDF
Collections
Astronomy Department Faculty Publication Series