相关论文: Beppo-Sax Observation of the Coma cluster

We report on the 0.5--200 keV spectral properties of Cyg X-1 observed at different epochs with the Narrow Field Instruments of the BeppoSAX satellite. The source was in its soft state during the first observation of 1996 June. In the second…

This paper provides a new analysis of ROSAT observations of the Coma cluster, to determine the amount of soft X--ray radiation in excess of the contribution from the hot intra--cluster medium. The re--analysis is made possible by a…

Millisecond pulsars are very likely the main source of gamma-ray emission from globular clusters. However, the relative contributions of two separate emission processes--curvature radiation from millisecond pulsar magnetospheres vs. inverse…

Chandra X-ray Observatory observations of the powerful, peculiar radio galaxy 3C123 have resulted in an X-ray detection of the bright eastern hotspot, with a 1-keV flux density of ~ 5 nJy. The X-ray flux and spectrum of the hotspot are…

BeppoSAX observed the Seyfert 1 galaxy NGC 3783 for ~ 5 days from 1998 June 6 to 1998 June 10. The average flux during the observation was F(2-10 keV) ~ 6 X 10^{-11} erg cm^-2 s^-1. The long exposure provided a very high quality spectrum…

NASA's Small Explorer Mission GEMS (Gravity and Extreme Magnetism SMEX), scheduled for launch in 2014, will have the sensitivity to detect and measure the linear polarization properties of the 0.5 keV and 2-10 keV X-ray emission of a…

We present a deep, 8$\degr$ diameter, 0.4 GHz radio image using a first time combination of the NAIC Arecibo 305-m telescope in Puerto Rico, and the wide-angle interferometer at the Dominion Radio Astrophysical Observatory at Penticton,…

After confirmation of the presence of a nonthermal hard X-ray excess with respect to the thermal emission in the Coma cluster from two independent observations, obtained using the Phoswich Detection System onboard BeppoSAX, we present in…

We present Chandra observations of two relatively high redshift FRII radio galaxies, 3C 432 and 3C 191 (z=1.785 and z=1.956 respectively), both of which show extended X-ray emission along the axis of the radio jet or lobe. This X-ray…

The presence of non-thermal electrons and large scale magnetic fields in the intra-cluster medium (ICM) is known through the detection of mega-parsec (Mpc) scale diffuse radio synchrotron emission. Although a significant amount of progress…

The spectrum of the 1.0-8.0 keV cosmic X-ray background (CXB) at galactic latitudes > 25 degrees has been measured using the BeppoSAX LECS and MECS instruments. The spectrum is consistent with a power-law of photon index 1.40 +/- 0.04 and…

Analyses of Fermi Gamma-Ray Space Telescope data have revealed a source of excess diffuse gamma rays towards the Galactic center that extends up to roughly $\pm$20 degrees in latitude. The leading theory postulates that this GeV excess is…

We suggest that the luminous extreme ultraviolet (EUV) emission which has been detected recently from clusters of galaxies is Inverse Compton (IC) scattering of Cosmic Microwave Background (CMB) radiation by low energy cosmic ray electrons…

We present X-ray observations of two high redshift clusters of galaxies carried out with the BeppoSAX satellite. One cluster, RXJ0152.7-1357 at z = 0.83, was selected from the ROSAT Deep Cluster Survey sample, as one of the most X-ray…

The existence of magnetic fields associated with the intracluster medium in clusters of galaxies is now well established through different methods of analysis. Magnetic fields are investigated in the radio band from studies of the rotation…

We have obtained deep and wide field imaging of the Coma cluster of galaxies with the CFH12K camera at CFHT in the B, V, R and I filters. In this paper, we present the observations, data reduction, catalogs and first scientific results. We…

We present high-resolution, high-sensitivity upgraded Giant Metrewave Radio Telescope observations of the Coma cluster (A1656) at 250-500 MHz and 550-850 MHz. At 250-500 MHz, 135 sources have extensions $>$ 0.45 arcmin (with…

The radio spectral index map of the Coma halo shows a progressive steepening of the spectral index with increasing radius. Such a steepening cannot be simply justified by models involving continuous injection of fresh particles in the Coma…

We wish to estimate magnetic field strengths of radio emitting galaxy clusters by minimising the non-thermal energy density contained in cosmic ray electrons (CRe), protons (CRp), and magnetic fields. The classical minimum energy estimate…

While hot ICM in galaxy clusters makes these objects powerful X-ray sources, the cluster's outskirts and overdense gaseous filaments might give rise to much fainter sub-keV emission. Cosmological simulations show a prominent "focusing"…