相关论文: New Results from Chandra
A common feature of the X-ray bubbles observed in Chandra images of some "cooling flow" clusters is that they appear to be surrounded by bright, cool shells. Temperature maps of a few nearby luminous clusters reveal that the shells consist…
We report on the deep Chandra observation of central r=200kpc region of the cluster of galaxies MKW3s which was previously identified as a moderate cooling flow cluster. The Chandra image reveals two striking features -- a 100kpc long and…
We present preliminary results from a deep observation lasting almost 200 ks, of the centre of the Perseus cluster of galaxies around NGC 1275. The X-ray surface brightness of the intracluster gas beyond the inner 20 kpc, which contains the…
Chandra is revolutionising our understanding of the X-ray emission from spiral galaxies. Before Chandra, detailed extragalactic studies were limited to Local Group galaxies. We are now able to obtain detailed inventories of sources in…
Deviations of galaxy groups from cluster scaling relations can be understood in terms of an excess of entropy in groups. The main effect of this excess is to reduce the density and thus luminosity of the intragroup gas. Given this, groups…
The role of energetic outflows from galactic nuclei in shaping galaxy formation and evolution is still shrouded in uncertainty. In this study, we shed light on this complex phenomenon by presenting evidence for a large-scale bipolar…
The number of diffuse radio halos in clusters of galaxies has grown in recent years, making it possible to derive statistical properties of these sources and of the hosting clusters. We show that diffuse sources are associated with X-ray…
We present Chandra observations of two star-forming galaxies (M82 and the Antennae) and three starburst/AGN composite galaxies (NGC1808, NGC6240, NGC7331). In both star-forming galaxies we detect a large number of sources with diverse…
The X-ray emission from clusters of galaxies enables them to be used as good cosmological probes and as an example for massive galaxy formation. The gas mass fraction in clusters should be a universal standard which by means of Chandra…
We present the Chandra analysis of the galaxy cluster A521 (z=0.247). The high resolution of the Chandra observation has allowed us to refine the original merging scenario proposed for A521, and to reveal new features in its X-ray emission.…
We have analyzed the Chandra observation of the distant (z=0.164) galaxy cluster RXJ1720.1+2638 in which we find sharp features in the X-ray surface brightness on opposite sides of the X-ray peak: an edge at about 250 h_50^{-1} kpc to the…
This paper reports on the early Chandra view of the Galactic center (GC) activities. The massive black hole Sgr A* is extremely faint, while more bright diffuse X-ray emission is prevailing in the circumnuclear disk. Another high…
In re-analyzing the archival Chandra data of the globular cluster 47 Tucanae, we have detected a new diffuse X-ray emission feature within the half-mass radius of the cluster. The spectrum of the diffuse emission can be described by a…
The number of known diffuse radio sources in clusters of galaxies has grown in recent years, making it possible to derive statistical properties of these sources and of the hosting clusters. We show that diffuse sources are associated with…
Clusters of galaxies are large gravitationally bound systems which consist of several observable components: hundreds of galaxies, hot gas between the galaxies and sometimes relativistic particles. These components are emitting in different…
We present results from Chandra observations of the galaxy pair and associated galaxy group NGC 5098, and find evidence for both gas sloshing and AGN heating. The X-ray brightness images show diffuse emission with a spiral structure,…
Clusters of galaxies can be seen as giant astrophysical laboratories enclosing matter in a large enough volume, so that the matter composition can be taken as representing the composition of our Universe. X-ray observations allow a very…
We present first results from a very deep (~650 ksec) Chandra X-ray observation of Abell 2052, as well as archival VLA radio observations. The data reveal detailed structure in the inner parts of the cluster, including bubbles evacuated by…
Clusters of galaxies generally form by the gravitational merger of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. The basic properties of cluster mergers and their…
Evidence for non-thermal activity in clusters of galaxies is well established from radio observations of synchrotron emission by relativistic electrons. New windows in the Extreme Ultraviolet and Hard X-ray ranges have provided for more…