Related papers: Gamma-loud quasars: a view with BeppoSAX

Results are presented on the X-ray properties of 9 high-redshift (1.2 < z < 3.4) radio-loud quasars (RLQs) observed by ASCA (10 observations) and ROSAT (11 observations, for a subset of 6 quasars). New ASCA observations of S5 0014+81 (z =…

The results from an X-ray spectral analysis of a large sample of quasars, observed with ASCA, are presented. Data reduction leaves 62 quasars, 35 radio-loud and 27 radio-quiet, suitable for spectral analysis. Differences are found between…

We present multi-epoch optical spectra of the $\gamma$-ray bright blazar 1156+295 (4C +29.45, Ton 599) obtained with the 4.3~m Lowell Discovery Telescope. During a multi-wavelength outburst in late 2017, when the $\gamma$-ray flux increased…

We report an infrared 1-1.8 micron (J+H-bands), low-resolution (R=450) spectrogram of the highest-redshift radio-loud quasar currently known, SDSS J083643.85+005453.3, obtained during the spectroscopic commissioning run of the FLAMINGOS…

We present new joint XMM-Newton and NuSTAR observations of APM 08279+5255, a gravitationally-lensed, broad-absorption line quasar ($z=3.91$). After showing a fairly stable flux ($f_{\rm2-10}\simeq4-5.5\times10^{-13}\rm~erg~s^{-1}$) from…

(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…

Context. PKS 1510-089 is one of only a few flat spectrum radio quasars detected in the VHE (very-high-energy, > 100 GeV) gamma-ray band. Aims. We study the broadband spectral and temporal properties of the PKS 1510-089 emission during a…

During the last years, Ly$\alpha$ nebulae have been routinely detected around high-z, radio-quiet quasars (RQQs) thanks to the advent of sensitive integral field spectrographs. Constraining the physical properties of the Ly$\alpha$ nebulae…

We present continuum observations of a small sample of high-redshift, radio-loud AGN (radio galaxies and quasars) aimed at the detection of thermal emission from dust. Seven AGN were observed with IRAM and SEST at 1.25mm; two of them, the…

We present BeppoSAX results on the nearby starburst galaxy NGC 253. Although extended, a large fraction of the X-ray emission comes from the nuclear region. Preliminary analysis of the LECS/MECS/PDS ~0.2-60 keV data from the central 4'…

We present the results of the analysis of the hard band XMM-Newton spectra of the luminous, L(2-10keV)~3.4E+45 erg/s, radio-quiet quasar, E1821+643. Two emission features were observed in the 6-7 keV rest frame band, confirming previous…

We report results of a BeppoSAX observation of the low-mass X-ray binary (LMXB) dipping source XB 1916-053. The source joins the small group of LMXB detected at energies ~100 keV. The non-dip spectrum is well fitted by an absorbed blackbody…

The newly discovered z=5.8 quasar SDSSp J104433.04-012502.2 was recently detected in X-rays and found to be extremely X-ray weak. Here we present the hardness ratio analysis of the XMM-Newton observation. We consider various models to…

Distant luminous quasars provide important information on the growth of the first supermassive black holes, their host galaxies and the epoch of reionization. The identification of quasars is usually performed through detection of their…

X-ray and multi-wavelength observations of the most luminous known local (z<0.3) AGN, the recently discovered radio-quiet quasar PDS 456, are presented. The spectral energy distribution shows that PDS 456 has a bolometric luminosity of 1e47…

We report on the identification of a new soft gamma ray source, namely IGR J22517+2218, detected with IBIS/INTEGRAL. The source, which has an observed 20-100 keV flux of ~4 x10^-11 erg cm-2 s-1, is spatially coincident with MG3…

We present results from Keck I high resolution spectroscopy of the radio loud quasar PKS 0123+257 ($z_e$=2.364, V=17.5). In this object we detect Ly$\alpha$, N V 1238,1242, Si IV 1393,1402, and C IV 1548,1550 in an absorption system at a…

We present high resolution (< 20 mas) observations of the radio continuum emission at 1.4 GHz from three high-redshift quasars: J1053-0016 (z=4.29), 1235-0003 (z=4.69), and J0913+5919 (z=5.11), thereby doubling the number of z > 4…

We report simultaneous observations at different energy bands in radio, optical, UV, X-rays and $\gamma$ rays of the flat-spectrum radio-quasar 3C 345. We built the light curve of the source at different frequencies from 2008, the beginning…

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…