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Pulsar systems accelerate particles to immense energies. The detailed functioning of these engines is still poorly understood, but polarization measurements of high-energy radiation may allow us to locate where the particles are accelerated. We have detected polarized gamma rays from the vicinity of the Crab pulsar using data from the spectrometer on the(More)
The gamma-ray astronomical observatory INTEGRAL, succesfully launched on 17 th October 2002, carries two large gamma-ray telescopes. One of them is the coded-mask imaging gamma-ray telescope onboard the INTEGRAL satellite (IBIS) which provides high-resolution (≈ 12 ′) sky images of 29 • × 29 • in the energy range from 15 keV to 10 MeV with typical on-axis(More)
The true nature of the progenitor to GRBs remains elusive; one characteristic that would constrain our understanding of the GRB mechanism considerably is gamma-ray polarimetry measurements of the initial burst flux. We present a method that interprets the prompt GRB flux as it Compton scatters off the Earth's atmosphere, based on detailed modelling of both(More)
Fast X-ray Transients (FXTs) are believed to be non-recurrent bright X-ray sources lasting less than a day and occuring at serendipitous positions, they can best be detected and discovered by instruments having a sufficiently wide field of view and high sensitivity. The IBIS/ISGRI instrument onboard INTEGRAL is particularly suited to detect new or already(More)
Aims. We communicate the detection of soft (20–200 keV) γ-rays from the pulsar and pulsar wind nebula of PSR J1846−0258 and aim to identify the component of the system which is responsible for the γ-ray emission. Methods. We combine spectral information from the INTEGRAL γ-ray mission with archival data from the Chandra X-ray Observatory to pinpoint the(More)
Swift-XRT observation of 34 new INTEGRAL/IBIS AGNs: discovery of Compton thick and other peculiar sources. ABSTRACT For a significant number of the sources detected at high energies (>10 keV) by the INTEGRAL/IBIS and Swift/BAT instruments there is either a lack information about them in the 2-10 keV range or they are totally unidentified. Herein, we report(More)
Optical spectroscopic identification of the nature of 21 unidentified southern hard X–ray objects is reported here in the framework of our campaign aimed at determining the nature of newly-discovered and/or unidentified sources detected by INTEGRAL. Our results show that 5 of these objects are magnetic Cataclysmic Variables (CVs), 4 are High-Mass X–ray(More)
A series of biaryl acids has been found to show micromolar inhibition of the HIV reverse transcriptase (RT) from types 1 and 2 with IC50S in the micromolar range. The series was discovered by consideration of the polymerase active site and sub-structure searching of the company compound collection. Synthesis of analogues to investigate the SAR is described.(More)
We present the results of our optical spectrophotometric campaign ongoing at the Astronomical Observatory of Bologna in Loiano (Italy) on hard X-ray sources detected by INTEGRAL. We observed spec-troscopically the putative optical counterparts of four more INTEGRAL sources, IGR J12391−1610, IGR J18406−0539, 2E 1853.7+1534 and IGR J19473+4452. These data(More)
We present further results from our onging optical spectrophotometric campaign at the Astronomical Observatory of Bologna in Loiano (Italy) on unidentified hard X–ray sources detected by INTEGRAL. We observed spectroscopically the putative optical counterparts of the INTEGRAL sources IGR J00234+6141, IGR J01583+6713, IGR J06074+2205, IGR J13091+1137 and IGR(More)