相关论文: ROSAT X-ray observations of 3CRR radio sources
HST observations have shown that low-redshift 3CR radio galaxies often exhibit a point-like optical component positionally coincident with the GHz-frequency radio core. In this paper we discuss the correlation between the luminosities of…
A database of radio-quiet quasars detected with ROSAT is presented containing 846 quasars seen in the All-Sky Survey and/or in pointed PSPC observations. About 70% of the objects have been detected in X-rays for the first time. We present…
We report on ROSAT HRI observations of the z=0.61 radio galaxy 3C220.1. The X-ray emission from this object consists of an extended component, which we attribute to luminous cluster emission, and a compact central source. The compact…
We present 5 GHz high resolution VLA observations of 2,127 radio- and X-ray-emitting sources found in both the Green Bank (GB) 5 GHz radio catalog and the ROSAT All-Sky Survey (RASS). We report core flux densities and positions accurate to…
We report the detection of extended X-ray emission around several powerful 3CR quasars with redshifts out to 0.73. The ROSAT HRI images of the quasars have been corrected for spacecraft wobble and compared with an empirical point-spread…
From ROSAT imaging data we have detections and upper limits for a sample of 26 tailed radio sources in clusters of galaxies mostly from the sample of O'Dea \& Owen (1985). All sixteen of the detected sources are unresolved in the ROSAT PSPC…
We announce the detection of correlations on angular scales of $\ga10'$ between optically bright, high-redshift, radio-loud QSOs with diffuse X-ray emission seen by ROSAT in the {\it All-Sky Survey}. These correlations reach significance…
The reason for the difference in the composite X-ray spectrum between radio-loud quasars (RLQs) and radio-quiet quasars (RQQs) is still unclear. To study this difference, we built a new composite X-ray spectrum of RLQs by using Chandra…
We present an analysis of X-ray data, taken with ROSAT, for a well defined sample of low-power radio galaxies from the Bologna B2 catalogue. Where possible, the HRI has been used in order to take advantage of the higher spatial resolution…
We report on the detection of a soft spatially-extended component of X-ray emission around four intermediate-redshift 3C quasars observed with Chandra: 3C254, 3C263, 3C275.1 and 3C281. The bolometric luminosity of this emission ranges over…
We review recent examples where the synergy between radio and X-ray observations has led to substantial progress in understanding astronomical systems. The sub-arcsecond imaging capabilities of the Chandra X-ray observatory provides a…
Investigations of the cluster environment of radio sources have not shown a correlation between radio power and degree of clustering. However, it has been demonstrated that extended X-ray luminosity and galaxy clustering do exhibit a…
We combine Chandra and XMM-Newton X-ray data from our previous papers with new X-ray observations and with Spitzer mid-infrared data in order to study the nature of the nuclei of radio galaxies and radio-loud quasars with z<1.0 from the…
This paper presents the analysis of Chandra X-ray snapshot observations of a subsample of the extragalactic sources listed in the revised Third Cambridge radio catalog (3CR), previously lacking X-ray observations and thus observed during…
We combine results from ROSAT, Chandra, and multifrequency VLBA observations of the Compact Steep Spectrum quasar 3C 48. We infer that the X-ray spectrum of the nucleus is made up of a soft, variable, steep-spectrum component, and harder,…
We report the results of a search for X-ray emission from quasar host clusters at moderate redshift using the {\sl ROSAT} HRI. We detect no emission from the host clusters of 3C~263 (z=0.646) and PKS~2352-34 (z=0.706) to 3$\sigma$\ limits…
We present the soft X-ray (0.1--2.4 keV) properties of a complete sample of 88 southern radio sources derived from the Wall \& Peacock 2-Jy sample. It comprises 68 radio galaxies, 18 quasars and 2 BL Lac objects. Whereas both BL Lac objects…
We discuss ROSAT HRI X-ray observations of 33 very nearby galaxies, sensitive to X-ray sources down to a luminosity of approximately 10^38 erg/s. The galaxies are selected from a complete, volume limited sample of 46 galaxies with d<7 Mpc…
In the construction of an X-ray selected sample of galaxy clusters for cosmological studies, we have assembled a sample of 495 X-ray sources found to show extended X-ray emission in the first processing of the ROSAT All-Sky Survey. The…
Active galaxies are the most powerful engines in the Universe for converting gravitational energy into radiation, and their study at all epochs of evolution is therefore important. Powerful radio-loud quasars and radio galaxies have the…