GRB 130925A is one of the recent additions to the growing family of ultra-long gamma-ray bursts (GRBs; T90 1000 s). While the X-ray emission of ultra-long GRBs have been studied extensively in the past, no comprehensive radio data set has been obtained so far. We report here the early discovery of an unusual radio afterglow associated with the ultra-long GRB 130925A. The radio emission peaks a...

A BeppoSAX observation of the z=2.34 quasar PKS2149−306 produced a strong signal in the high energy PDS instrument up to a maximum observed energy of nearly 50 keV, 150 keV in the quasar frame. The Beppo-SAX spectrum spans almost 3 decades (0.3−150 keV, quasar frame) and shows an extremely hard (α=0.4±0.05) X-ray spectrum above 3 keV (comparable to XJB the X-ray background slope), and either a ...

We present here the analysis of ultraviolet spectra from IUE and an X-ray spectrum from ROSAT PSPC observations of the X-ray weak, far-infrared loud AGN, PG 1126−041 (Mrk 1298). The first UV spectra taken in June 1992, simultaneously with ROSAT, show strong absorption lines of NV, CIV and SiIV, extending over a velocity range from −1000 to −5000 km s with respect to the corresponding line centr...

The Galactic diffuse soft gamma-ray (30-800 keV) emission has been measured from the Galactic Center by the HIREGS balloon-borne germanium spectrometer to determine the spectral characteristics and origin of the emission. The resulting Galactic diffuse continuum is found to agree well with a single power-law (plus positronium) over the entire energy range, consistent with RXTE and COMPTEL/CGRO ...

Your thesaurus codes are: missing; you have not inserted them ASTRONOMY AND ASTROPHYSICS The first XMM-Newton spectrum of a high redshift quasar-PKS 0537−286. Abstract. We present XMM-Newton observations of the high redshift (z = 3.104), radio-loud quasar PKS 0537−286. The EPIC CCD cameras provide the highest signal-to-noise spectrum of a high-z quasar to date. The EPIC observations show that P...

SAX J1819.3–2525 is a nearby X-ray transient which exhibited a fast and large X-ray outburst on Sep. 15, 1999 (Smith et al. 1999). The Wide Field Cameras and the Narrow Field Instruments (NFI) on board BeppoSAX observed SAX J1819.3–2525 at various stages of its activity before that, in the spring and fall of 1999. The fluxes range between 0.012 and 0.3 Crab units (2–10 keV). The NFI observation...

We present the results from simultaneous observations of the Narrow-Line Seyfert 1 galaxy NGC 4051 with the Chandra High Energy Transmission Grating Spectrometer and the HST Space Telescope Imaging Spectrograph. The X-ray grating spectrum reveals absorption and emission lines from hydrogen-like and helium-like ions of O, Ne, Mg and Si. We resolve two distinct X-ray absorption systems: a high-ve...

We present an XMM-Newton observation of the long-overlooked radio source G350.1–0.3. The X-ray spectrum of G350.1–0.3 can be fit by a shocked plasma with two components: a high-temperature (1.5 keV) region with a low ionization time scale and enhanced abundances, plus a cooler (0.36 keV) component in ionization equilibrium and with solar abundances. The X-ray spectrum and the presence of non-th...

We report on Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of the young rotationpowered radio pulsar PSR B1509−59 in the supernova remnant MSH 15−52. We confirm the previously reported curvature in the hard X-ray spectrum, showing that a log parabolic model provides a statistically superior fit to the spectrum compared with the standard power law. The log parabolic mode...