Related papers: X-rays from the Highly Polarized Broad Absorption …
We report on the spectral confirmation of 18 QSO candidates from the "QUasars as BRIght beacons for Cosmology in the Southern hemisphere'' survey (QUBRICS), previously observed in the optical band, for which we acquired new spectroscopic…
We report on the BeppoSAX monitoring of a giant outburst of the transient X-ray pulsar XTE J1946+274 in 1998. The source was detected with a flux of ~ 4 x 10^(-9) erg cm^(-2) s^(-1) (in 0.1 - 120 keV range). The broadband spectrum, typical…
The integrated emission of highly obscured AGN is expected to provide a major contribution to the X-ray energy density in the Universe: the X-ray background (XRB). The study of these objects is possible only at energies where the effects of…
BeppoSAX observed the z=3.27 quasar PKS2126-158 on 1999 May 24-28 when its 2-10keV and 0.1-2.5keV fluxes were 1.1E-11 and 4.4E-12 cgs respectively, a factor of 2 higher than in all previous ROSAT and ASCA observations and 40% higher than in…
We report optical, radio and X-ray observations of the Narrow-Line Seyfert 1 galaxy RX J1702.5+3247. The soft (0.1-2 keV) X-ray flux, measured by BeppoSAX, is characterized by strong variability on short time scales (< 500 sec). The most…
(Abridged) Spectral and time variability analysis of the region of the hard X-ray transient EXS 1737.9-2952 near the Galactic Centre (GC), using data from the Narrow Field Instruments of BeppoSAX is reported. The main results are the MECS…
Broad absorption line (BAL) features in quasar spectra reveal an unambiguous signature of energetic outflows from central supermassive black holes, and thus BAL quasars are prime targets for investigating the potential process of luminous…
We develop and apply a novel method of analysis to study the X-ray spectral properties of 908 QSOs in the Large Bright Quasar Survey (LBQS) that were observed during the soft X-ray ROSAT All-Sky Survey (RASS). Due to the relatively short…
In the deepest optically identified X-ray survey yet performed, we have identified 32 X-ray selected QSOs to a flux limit of 2x10^{-15} erg cm^{-2} s^{-1} (0.5-2 keV). The survey, performed with the ROSAT PSPC, has 89% spectroscopic…
We present the discovery of strong Balmer line absorption in H$\alpha$ to H$\gamma$ in two luminous low-ionization broad absorption line quasars (LoBAL QSOs) at z~1.5, with black hole masses around $10^{10}$ $M_\odot$ from near-IR…
A sample of 67 Broad Absorption Line quasars (BALQSOs) from the Large Bright Quasar Survey (LBQS) is used to estimate the observed and intrinsic fraction of BAL quasars in optically--selected samples at intermediate (B_J \simeq 18.5)…
We present UV and optical spectropolarimetry of two highly polarized IRAS-selected QSOs, IRAS 13349+2438 and the BALQSO IRAS 14026+4341. The polarization in both objects rises rapidly toward the blue, peaks near 3000 A in the rest frame and…
We report on spectral and timing analysis of BeppoSAX data of the 13.6 s period transient X-ray pulsar EXO 0531-6609.2. Observations were carried out in March 1997 and October 1998, catching the source during a high and a low emission…
New linear polarization measurements (mainly in the V band) are presented for 203 quasi-stellar objects (QSOs). The sample is made up of 94 QSOs located in the North Galactic Pole (NGP) region and of 109 QSOs in the South Galactic Pole…
We present broad-band (0.1--90keV) spectral and temporal properties of the three Intermediate Polars, RE0751+144 (PQ Gem), RXJ0558.0+5353 (V405Aur) and RXJ1712.6-2414 (V2400 Oph) based on simultaneous soft and hard X-ray observations with…
Spectropolarimetry of Broad Absorption Line Quasars (BALQSO's) has demonstrated that the geometry of the absorbing material is far from spherically symmetric. Calculations of accretion disk spectra suggest that the intrinsic radiation…
We present polarization measurements in the $2-8 \thinspace \mathrm{keV}$ band from blazar 1ES 0229+200, the first extreme high synchrotron peaked source to be observed by the Imaging X-ray Polarimetry Explorer (IXPE). Combining two…
We present the multiwavelength spectral energy distributions (SEDs) for 65 luminous broad absorption line (BAL) quasars with redshifts $1.55 \lesssim z \lesssim 3.50$ from the Gemini Near Infrared Spectrograph - Distant Quasar Survey…
We present a phase resolved spectral analysis of the X-ray binary 4U0115+63 based upon Beppo-Sax satellite observations. Three strong absorption lines have been detected at all phases. We interpreted them as a cyclotron resonant scattering.…
New multi-frequency radio observations of a large sample of radio-selected BAL quasars, along with a very well matched sample of normal quasars, are presented. The observations were made one immediately after the other at 4.9 and 8.4 GHz…