相关论文: Model-independent X-ray mass determinations
The mass of a cluster of galaxies can be estimated from its lens magnification, which can be determined from the variation in number counts of background galaxies. In order to derive the mass one needs to make assumptions for the lens…
Breast cancer is one of the most common and prevalent type of cancer that mainly affects the women population. chances of effective treatment increases with early diagnosis. Mammography is considered one of the effective and proven…
Temperature of the hot gas in galaxy clusters is known to be a reliable proxy for their total gravitating mass, allowing one to use spectroscopic X-ray observations for halo mass function measurements. Data of shallow wide area surveys,…
Context. Whereas X-ray clusters are extensively used for cosmology, their idealistic modelling, through the hypotheses of spherical symmetry and hydrostatic equilibrium, are more and more being questioned. Along these lines, the soft X-ray…
Results of a study of the theoretically predicted and observed X-ray properties of local massive star clusters are presented, with a focus on understanding the mass and energy flow from these clusters into the ISM via a cluster wind. A…
The state of the hot gas in clusters of galaxies is investigated with a set of model clusters, created by assuming a polytropic equation of state (Gamma=1.2) and hydrostatic equilibrium inside gravitational potential wells drawn from a dark…
Galaxy clusters, the largest clearly defined objects in our Universe, are ideal laboratories to study in detail the cosmic evolution of the intergalactic intracluster medium (ICM) and the cluster galaxy population. For the ICM, which is…
The detection of clusters of galaxies in large surveys plays an important part in extragalactic astronomy, and particularly in cosmology, since cluster counts can give strong constraints on cosmological parameters. X-ray imaging is in…
We present the results of our analyses of the X-ray emission and of the strong lensing systems in the relaxed galaxy cluster Abell 611 (z=0.288). We infer the X-ray mass estimate deriving the density and temperature profiles of the…
We present an analysis of the properties of the lensing cluster MS0440+0204 at z=0.1965. MS0440+0204 has been observed with a variety of telescopes at diverse wavelengths: from the ground with CFHT, MMT and KECK and from Earth orbit with…
The mass measurement of galaxy clusters is an important tool for the determination of cosmological parameters describing the matter and energy content of the Universe. However, the standard methods rely on various assumptions about the…
We present a consistent analysis of Chandra and XMM-Newton observations of an approximately mass-selected sample of 50 galaxy clusters at $0.15<z<0.3$ -- the "LoCuSS High-$L_X$ Sample". We apply the same analysis methods to data from both…
(Abridged) Based on XMM-Newton, Chandra and SDSS data, we investigate the baryon distribution in groups and clusters and its use as a cosmological constraint. For this, we considered a sample of 123 systems, with total masses in the mass…
Clusters of galaxies can be used for very different kinds of cosmological tests. I review a few of the methods: determination of cluster masses and dark matter content, metal enrichment and its connection to the origin of the intra-cluster…
We propose a new cosmological test of gravity, by using the observed mass fraction of X-ray emitting gas in massive galaxy clusters. The cluster gas fraction, believed to be a fair sample of the average baryon fraction in the Universe, is a…
In current models used to interpret exoplanet atmospheric observations, the planet mass is treated as a prior and is estimated independently with external methods, such as RV or TTV techniques. This approach is necessary as available…
This presentation is a Moriond version of our recent paper (Kravtsov, Vikhlinin & Nagai astro-ph/0603205) where we discussed X-ray proxies for the total cluster mass, including the spectral temperature (Tx), gas mass measured within r500…
Recent hydrostatic X-ray studies of the hot interstellar medium (ISM) in early-type galaxies underestimate the gravitating mass as compared to stellar dynamics, implying modest, but significant deviations from exact hydrostatic equilibrium.…
One of the main limitations in precision cluster cosmology arises from systematic errors and uncertainties in estimating cluster masses. Using the Mock-X pipeline, we produce synthetic X-ray images and derive cluster and galaxy group X-ray…
We present a new method for estimating galaxy cluster masses using weak-lensing magnification. The effect of weak-lensing magnification introduces a correlation between the position of foreground galaxy clusters and the density of…