Related papers: Probing accretion activity in radio sources using …

A complete sample of bright ROSAT sources with hard XRB-like spectra in the Galactic Plane (|b| < 15 deg.) has been tentatively identified with radio sources in the GB6/PMN/NVSS surveys, and subsequently observed with the Australia…

We study the correlation between the radio, mid-infrared and far-infrared properties for a sample of 28 blue compact dwarf (BCD) and low metallicity star-forming galaxies observed by Spitzer. We find that these sources extend the same…

We present 6-GHz Very Large Array radio images of 70 gravitational lens systems at 300-mas resolution, in which the source is an optically-selected quasar, and nearly all of which have two lensed images. We find that about in half of the…

Infrared-faint radio sources (IFRSs) are a rare class of object which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these…

We present spectroscopic and eleven-band photometric redshifts for galaxies in the 100-uJy Subaru/XMM-Newton Deep Field radio source sample. We find good agreement between our redshift distribution and that predicted by the SKA Simulated…

We match quasars discovered in a multi-color survey centered on the northern Hubble Deep Field (HDF) with radio sources from an ultra-deep radio survey. Although 3 out of 12 quasars are detected at a level below 0.2 mJy at 1.4 GHz, all of…

We have combined a survey at 24 microns to 0.3 mJy with the Multiband Imaging Photometer (MIPS) on the Spitzer Space Telescope, a 20 cm A-array VLA survey covering 0.5 deg^2, and an existing 172 ks Chandra X-Ray Observatory exposure to…

Infrared-Faint Radio Sources (IFRSs) are a class of source which are bright at radio frequencies, but do not appear in deep infrared images. We report the detection of 14 IFRSs within the Spitzer extragalactic First Look Survey field, eight…

We present the Swift optical to X-ray spectral energy distributions (SEDs) of 44 quasars at redshifts z~2 observed by Swift, part of a larger program to establish and characterize the optical through X-ray SEDs of moderate-redshift quasars.…

It has been proposed that the radio spectra of radio-quiet quasars is produced by free-free emission in the optically thin part of an accretion disc wind. An important observational constraint on this model is the observed X-ray luminosity.…

We investigate the infrared / radio correlation using the technique of source stacking, in order to probe the average properties of radio sources that are too faint to be detected individually. We compare the two methods used in the…

We present the results of a search for galaxy clusters in Subaru-XMM Deep Field. We reach a depth for a total cluster flux in the 0.5-2 keV band of 2x10^{-15} ergs cm^{-2} s^{-1} over one of the widest XMM-Newton contiguous raster surveys,…

Optically very faint R>25.5 sources detected by the Spitzer Space Telescope at 24um represent a very interesting population at redshift z [1.5-3]. They exhibit strong clustering properties, implying that they are hosted by very massive…

The radio properties of hard (2-8keV) X-ray selected sources are explored by combining a single 50ks XMM-Newton pointing with the ultra-deep and homogeneous Phoenix radio (1.4GHz) survey (Hopkins et al. 2003). A total of 43 sources are…

We present XMM-Newton imaging spectroscopy of ten weak emission-line quasars (WLQs) at $0.928\leq z \leq 3.767$, six of which are radio quiet and four which are radio intermediate. The new X-ray data enabled us to measure the power-law…

We present Spitzer observations in five wavebands between 3.6 and 24um of an unbiased sample of 9 luminous, dusty galaxies selected at 1200um by the MAMBO camera on the IRAM 30-m telescope, a population akin to the well-known submm or…

We present Swift observations of 31 sources from the SMS4 catalog, a sample of 137 bright radio sources in the Southern Hemisphere. All these sources had no Chandra or XMM-Newton observations: 24 of these were observed with Swift through a…

We present a Spitzer mid-infrared survey of 42 Fanaroff-Riley class II radio galaxies and quasars from the 3CRR catalog at redshift z<1. All of the quasars and 45+/-12% of the narrow-line radio galaxies have a mid-IR luminosity of nuLnu(15…

We carried out an unbiased, spectroscopic survey using the low-resolution module of the infrared spectrograph (IRS) on board Spitzer targeting two 2.6 square arcminute regions in the GOODS-North field. IRS was used in spectral mapping mode…

We employ X-ray stacking techniques to examine the contribution from X-ray undetected, mid-infrared-selected sources to the unresolved, hard (6-8 keV) cosmic X-ray background (CXB). We use the publicly available, 24 micron Spitzer Space…