Universal gas density and temperature profile

By E. Komatsu, Uros Seljak. 2001

188 citations recorded by the source corpus.

We present an analytic approach to predict gas density and temperature profiles in dark matter haloes. We assume that the gas density profile traces the dark matter density profile in outer parts of the haloes, as suggested by many hydrodynamic simulations. Under this assumption, the hydrostatic equilibrium uniquely fixes the two free parameters in the model, the mass–temperature normalization and the polytropic index, that determine the temperature profile. This enables us to predict a universal gas profile from any universal dark matter profile. Our results show that gas tracing dark matter in the outer parts of the haloes is inconsistent with gas being isothermal; on the contrary, it requires temperature to decrease slowly with radius, in agreement with observations. We compare our predictions for X-ray surface brightness profiles of the haloes and the mass–temperature relation with observations. We find that they are generally in good agreement. We compare the universal profile with the β profile and find that, although the β profile gives a reasonable fit to our predicted profiles, the deviation from it can explain many of the observed trends, once we take into account the observational selection effects. Our model predicts that the mass–temperature relation does not follow the self-similar relation because of the mass-dependent halo concentration. We also predict surface brightness profiles of the Sunyaev–Zel'dovich (SZ) effect. We find that fitted to the β-profile the core radii and β inferred from the SZ effect are systematically larger than those from the X-ray measurement.

Subfields: Astronomy and Astrophysics, Instrumentation, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/9f7b41f9f06a0a54f4b25f7bc34223b73b0d39dd

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

In Nuclear and High Energy Physics

Citations in the corpus

The mass profile of A1413 observed with XMM-Newton: Implications for the M-T relation (2002, methodology): “Assuming that the gas density profile follows the dark matter profile at large radii (within a factor of 2 between r200/2 and 2r200) and a polytropic equation of state, Komatsu & Seljak (2001) derived an analytical solution of the gas in HE in an NFW profile.”
A dynamical model for the distribution of dark matter and gas in galaxy clusters (2003, unknown): “…matter density profile, it is possible to calculate the radial distribution of the hot gas by imposing the hydrostatic equilibrium equation and assuming that the gas is either isothermal or polytropic (e.g. Suto, Sasaki & Makino 1998; Komatsu & Seljak 2001; Ascasibar et al. 2003, hereafter AYMG03).”
Modified Entropy Models for the Intracluster Medium (2002, background): “9), a feature these models share with those of Komatsu & Seljak (2001).”
A Measurement of Large-Scale Peculiar Velocities of Clusters of Galaxies: Results and Cosmological Implications (2008, background): “In order to be in hydrostatic equilibrium 3n ∝ re such gas must have temperature decreasing with radius (Komatsu & Seljak 2001).”
The Sunyaev-Zel'dovich angular power spectrum as a probe of cosmological parameters (2002, methodology): “For comparison, the figure also plots the fitting formula which we have given for 4 c 11 in Komatsu & Seljak (2001).”
A NEW MEASUREMENT OF THE BULK FLOW OF X-RAY LUMINOUS CLUSTERS OF GALAXIES (2009, background): “The temperature TX of hot gas distributed according to these profiles decreases significantly from the cluster cores to the cluster outskirts (Komatsu & Seljak 2001), consistent with current measurements (Pratt et al. 2007) and numerical simulations (e.g., Borgani et al. 2004).”
A Catalog of Galaxy Clusters Observed by XMM-Newton (2007, background): “…the total mass that is in gas is constant with radius results in a prediction that the cluster gas should have a declining temperature profile at a sufficiently large distance from the center (in R/Rviral units), both from analytic (Komatsu & Seljak 2001) and numerical modeling (Loken et al. 2002).”
X‐ray properties of galaxy clusters and groups from a cosmological hydrodynamical simulation (2003, background): “As for the core radius, both theoretical arguments (e.g., Komatsu & Seljak 2001) and observational data (e.g., F01) indicate that it is generally of the order of one–tenth of r500 so that the correction term in Eq.”
An improved SPH scheme for cosmological simulations (2015, methodology): “We set up the initial equilibrium conditions following Komatsu & Seljak (2001), as described in Viola et al. (2008).”
Radiative Transfer Simulations of Cosmic Reionization. I. Methodology and Initial Results (2006, methodology): “The dimensionless gas density profile has the analytical solution (e.g., Komatsu & Seljak 2001) yg(x) ¼ 1 A 1 ln (1þ x) x 1”
THE ATACAMA COSMOLOGY TELESCOPE: COSMOLOGICAL PARAMETERS FROM THE 2008 POWER SPECTRUM (2010, methodology): “The analysis for WMAP used the analytic Komatsu-Seljak (K-S) spectrum derived from a halo model (Komatsu & Seljak 2001).”
A new method to quantify the effects of baryons on the matter power spectrum (2015, unknown): “The polytropic index Γ is fixed by assuming the slope of the gas profile to equal the one from the NFW profile at r200/ √ 5, yielding [19]”
Triaxial Modeling of Halo Density Profiles with High-Resolution N-Body Simulations (2002, methodology): “…the gravitational potential of the hosting halos, one may compute the gas or temperature profiles, with an additional assumption of the hydrostatic equilibrium for instance, as performed in the NFW model (e.g., Makino, Sasaki & Suto 1998; Suto, Sasaki & Makino 1998; Komatsu & Seljak 2001).”
Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Cosmology (2006, unknown): “The amplitude of SZ fluctuations is very sensitive to 8 (Komatsu & Kitayama 1999; Komatsu & Seljak 2001).”