相关论文: Metallicity structure in X-ray bright galaxy group…
We compare the observed peaked iron abundance profiles for a small sample of groups and clusters with the predictions of a simple model involving the metal ejection from the brightest galaxy and the subsequent diffusion of metals by…
We investigate the metal enrichment of the intracluster medium (ICM) in the framework of hierarchical models of galaxy formation. We calculate the formation and evolution of galaxies and clusters using a semi-analytical model which includes…
Globular Clusters (GCs) are natural laboratories where stellar and chemical evolution can be studied in detail. In addition, their chemical patterns and kinematics can tell us wich Galactic structure (Disk, Bulge, Halo or extragalactic) the…
We present the results of a detailed element abundance study of hot gas in M87, observed by XMM-Newton. We choose two radial bins, 1'-3' and 8'-16' (8'-14' for EMOS; hereafter the central and the outer zones), where the temperature is…
Spectra of extranuclear clouds within the ionization cone of Circinus galaxy are presented and modelled assuming photoionization by the Seyfert 2 nucleus but no preconceived assumption concerning the spectral shape of the ionizing AGN…
We present herein a systematic X-ray analysis of blue galaxy-clusters at $z=0.84$ discovered by the Subaru telescope. The sample consisted of 43 clusters identified by combining red-sequence and blue-cloud surveys, covering a wide range of…
The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the…
We present an analysis of sixteen galaxy clusters, one group and one galaxy drawn from the Chandra X-ray Observatory's data archive. These systems possess prominent X-ray surface brightness depressions associated with cavities or bubbles…
We have investigated the baryon-mass content in a subsample of 19 clusters of galaxies extracted from the X-ray flux-limited sample HIFLUGCS according to their positions in the sky. For these clusters, we measured total masses and…
We observed a group of galaxies, HCG 57, with ASCA. Regardless that their member galaxies are dominated by spiral galaxies, we detected extended thermal X-ray emission that is attributed to hot gas with a temperature of $1.04\pm0.10$ keV.…
We have performed a systematic search for X-ray cavities in the hot gas of 51 galaxy groups with Chandra archival data. The cavities are identified based on two methods: subtracting an elliptical beta model fitted to the X-ray surface…
We study the physical properties of three clusters of galaxies, selected from a BeppoSAX Wide Field Camera (WFC) survey. These sources are identified as 1RXS J153934.7-833535, 1RXS J160147.6-754507, and 1RXS J081232.3-571423 in the ROSAT…
We present an analysis of the X-ray bright point source population in 43 massive clusters of galaxies observed with the Chandra X-ray Observatory. We have constructed a catalog of 4210 rigorously selected X-ray point sources in these…
Medium resolution spectra of more than 400 subgiant and turn-off region stars in Omega Centauri were analysed. The observations were performed at the VLT/Paranal with FORS2/MXU. In order to determine the metallicities of the sample stars,…
We present long-slit observations in the optical and near infrared of fourteen HII regions in the spiral galaxies: NGC 628, NGC 925, NGC 1232 and NGC 1637, all of them reported to have solar or oversolar abundances according to empirical…
The nitrogen and oxygen abundances in the warm ionized gas of low-mass, metal-poor galaxies appear surprisingly homogeneous considering the prevalence of large HII regions, which contain hundreds of massive stars. Of the six galaxies with…
Observed metal abundances in the intracluster medium (ICM) of galaxy groups and clusters, $Z_{ICM}$, exceed what is expected from present-day stellar populations alone. Galaxy clusters are presumed to be near closed-box systems, allowing…
We present the X-ray and optical properties of the galaxy groups selected in the Chandra X-Bo\"otes survey. Our final sample comprises 32 systems at \textbf{$z<1.75$}, with 14 below $z = 0.35$. For these 14 systems we estimate velocity…
We present the average abundances of the intermediate elements obtained by performing a stacked analysis of all the galaxy clusters in the archive of the X-ray telescope ASCA. We determine the abundances of Fe, Si, S, and Ni as a function…
The metal abundances in galactic nuclei carry key information on the history of star formation and mass transfer in central regions of galaxies. X-ray fluorescence analysis is a unique tool to reliably measure the abundances of various…