相关论文: X-ray scaling relations of early-type galaxies
In order to help understand the phenomena of X-ray emission from early-type galaxies, we obtained an optically flux-limited sample of 34 early-type galaxies, observed with ROSAT. A previous analysis of this sample suggested that the most…
The X-ray properties of a sample of high redshift (z>0.6), massive clusters observed with XMM-Newton and Chandra are described, including two exceptional systems. One, at z=0.89, has an X-ray temperature of T=11.5 (+1.1, -0.9) keV (the…
In this paper based on ROSAT/PSPC data we investigate the emission measure profiles of a sample of hot clusters of galaxies (kT>3.5keV) in order to explain the differences between observed and theoretically predicted L_X-T relation. Looking…
Recently, the temperature T and luminosity L_X of the hot gas halos of early type galaxies have been derived with unprecedented accuracy from Chandra data, for 30 galaxies covering a wider range of galactic luminosity (and central velocity…
We examine X-ray scaling relations for massive halos ($M_{500}>10^{12.3}M_\odot$) in the Simba galaxy formation simulation. The X-ray weighted luminosity, $L_X$ vs. $M_{500}$ has power-law slopes $\approx\frac{5}{3}$ and…
We re-examine the X-ray luminosity-temperature relation using a nearly homogeneous data set of 24 clusters selected for statistically accurate temperature measurements and absence of strong cooling flows. The data exhibit a remarkably tight…
We model the effects of shocks on the diffuse, X-ray emitting baryons in clusters of galaxies. Shocks separate the infalling from the inner gas nearly at equilibrium, and dominate the compression and the density gradients of the latter in…
We calibrate the galaxy cluster mass - temperature relation using the temperature profiles of intracluster gas observed with ASCA (for hot clusters) and ROSAT (for cool groups). Our sample consists of apparently relaxed clusters for which…
X-ray-emitting coronae of nearby galaxies are expected to be produced either by accretion from the intergalactic medium and/or by various galactic feedback. We herein present a systematical analysis of the Chandra observations of 53 nearby…
The scaling between X-ray observables and mass for galaxy clusters and groups is instrumental for cluster based cosmology and an important probe for the thermodynamics of the intracluster gas. We calibrate a scaling relation between the…
An X-ray survey with the XMM-Newton telescope, XMM-XXL, has identified hundreds of galaxy groups and clusters in two 25 deg$^2$ fields. Combining spectroscopic and X-ray observations in one field, we determine how the kinetic energy of…
While in the hierarchical model of structure formation, groups of galaxies are believed to be the scaled-down version of clusters of galaxies, a similarity breaking in the fundamental laws may occur on the group scale, reflecting a…
We present relations between X-ray luminosity and velocity dispersion (L-sigma), X-ray luminosity and gas mass (L-Mgas), and cluster radius and velocity dispersion (r500-sigma) for 62 galaxy clusters in the HIFLUGCS, an X-ray flux-limited…
The isotropy of the late Universe is an assumption greatly used in astronomy. However, many studies have recently reported deviations from isotropy with a definitive conclusion yet to be made. New, independent methods to robustly test the…
We determine X-ray temperatures and abundances for elliptical galaxies drawn from a complete, optically selected sample. The optical magnitude-limited sample consists of 43 galaxies, complete to a (corrected) B magnitude of m_B^o=11.36. Of…
Measurements of X-ray scaling laws are critical for improving cosmological constraints derived with the halo mass function and for understanding the physical processes that govern the heating and cooling of the intracluster medium. In this…
Results from a large sample of hydrodynamical/N-body simulations of galaxy clusters in a LCDM cosmology are used to simulate cluster X-ray observations as expected from Chandra observations. The physical modeling of the gas includes…
We analyse cosmological hydrodynamical simulations of galaxy clusters to study the X-ray scaling relations between total masses and observable quantities such as X-ray luminosity, gas mass, X-ray temperature, and $Y_{X}$. Three sets of…
A luminosity-temperature relation for clusters of galaxies is derived. The two models used, take into account the angular momentum acquisition by the proto-structures during their expansion and collapse. The first one is a modification of…
We present an analysis of the diffuse X-ray emission in 19 compact groups of galaxies (CGs) observed with Chandra. The hottest, most X-ray luminous CGs agree well with the galaxy cluster X-ray scaling relations in $L_X-T$ and $L_X-\sigma$,…