548 datasets found

The Fermi-Large Area Telescope (LAT) is currently the most important facility for investigating the GeV {gamma}-ray sky. With Fermi-LAT, more than three thousand {gamma}-ray...

We present a study of the parsec-scale multifrequency properties of the quasar S4 1030+61 during a prolonged radio and {gamma}-ray activity. Observations were performed within...

In the most recent IBIS survey based on observations performed during the first 1000 orbits of INTEGRAL, are listed 363 high-energy emitters firmly associated with AGN, 107 of...

This work is a summary of the X-ray spectral studies of 29TeV (10^12^eV, tera-electron-volt) {gamma}-ray emitting blazars observed with Swift/XRT, especially focusing on sources...

We report the results of the deepest Galactic plane (|b|<17.5{deg}) survey in the 67.9 and 78.4keV nuclear de-excitation lines of titanium-44 (^44^Ti) performed using the...

Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, yet the nature and physical properties of their energy sources are far from understood. Very important...

{gamma}-ray radiation from pulsars is usually thought to be mostly produced by the synchro-curvature (SC) losses of accelerated particles. Here, we present a systematic study of...

Based on a large Fermi blazar sample, the blazar sequence (synchrotron peak frequency {nu}peak versus synchrotron peak luminosity L_peak_) is revisited. It is found that there...

Gamma-ray burst (GRB) optical and X-ray afterglow luminosity is expected to correlate with the GRB isotropic equivalent kinetic energy of the outflow in the standard synchrotron...

We present first results from RoboPol, a novel-design optical polarimeter operating at the Skinakas Observatory in Crete. The data, taken during the 2013 May-June commissioning...

The exact location of the {gamma}-ray emitting region in blazars is still controversial. In order to attack this problem we present first results of a cross-correlation analysis...

We use optical data from the Palomar Transient Factory (PTF) and the Catalina Real-Time Transient Survey (CRTS) to study the variability of {gamma}-ray-detected and non-detected...

We present results from four years of twice-weekly 15GHz radio monitoring of about 1500 blazars with the Owens Valley Radio Observatory 40m telescope. Using the intrinsic...

In this work we present the most comprehensive INTEGRAL active galactic nucleus (AGN) sample. It lists 272 AGN for which we have secure optical identifications, precise optical...

Dark matter annihilation signals coming from Galactic subhaloes may account for a small fraction of unassociated point sources detected in the second Fermi-LAT Catalogue (2FGL)....

Machine learning, algorithms designed to extract empirical knowledge from data, can be used to classify data, which is one of the most common tasks in observational astronomy....

To find out the astrophysical processes responsible for gamma-ray burst (GRB), it is crucial to discover and understand the relations between their observational properties....

The most recent IBIS/ISGRI survey, i.e. the fourth one, lists 723 hard X-ray sources, many still unidentified, i.e. lacking an X-ray counterpart or simply not studied at lower...

We present a homogeneous X-ray analysis of all 318 Gamma Ray Bursts detected by the X-ray Telescope on the Swift satellite up to 2008 July 23; this represents the largest sample...

The Parkes Multibeam Pulsar Survey has unlocked vast areas of the Galactic plane, which were previously invisible to earlier low-frequency and less-sensitive surveys. The survey...