Related papers: AGILE and blazar studies
We report on 18 months of multiwavelength observations of the blazar 3C 454.3 (Crazy Diamond) carried out in July 2007-January 2009. We show the results of the AGILE campaigns which took place on May-June 2008, July-August 2008, and October…
The flat-spectrum radio quasar 4C $+$71.07 is a high-redshift ($z=2.172$), $\gamma$-loud blazar whose optical emission is dominated by the thermal radiation from accretion disc. 4C $+$71.07 has been detected in outburst twice by the AGILE…
We present a variability study of a sample of bright gamma-ray (30 MeV -- 50 GeV) sources. This sample is an extension of the first AGILE catalogue of gamma-ray sources (1AGL), obtained using the complete set of AGILE observations in…
The AGILE gamma-ray satellite accumulated data over two years on several blazars. Moreover, for all of the sources detected by AGILE, we exploited multiwavelength observations involving both space and ground based telescopes and consortia,…
In July 2007, the blazar 3C 454.3 underwent a flare in the optical, reaching R~13 on July 19. Then the optical flux decreased by one magnitude, being R~14 when the source was detected by the gamma-ray satellite AGILE, that observed the…
Since 2001, the radio quasar 3C 454.3 has undergone a period of high optical activity, culminating in the brightest optical state ever observed, during the 2004-2005 outburst. The Whole Earth Blazar Telescope (WEBT) consortium has carried…
We report the results of a 3-weeks multi-wavelength campaign on the flat spectrum radio quasar 3C 273 carried out with the AGILE gamma-ray mission, covering the 30 MeV -50 GeV and 18-60 keV, the REM observatory (covering the near-IR and…
We present the gamma-ray data of the extraordinary flaring activity above 100 MeV from the flat spectrum radio quasar 3C 454.3 detected by AGILE during the month of December 2009. 3C 454.3, that has been among the most active blazars of the…
We report on a systematic search for hard X-ray and gamma-ray emission in coincidence with fast radio bursts (FRBs) observed by the AGILE satellite. We used 13 years of AGILE archival data searching for time coincidences between exposed…
In the recent years, the new generation of Imaging Atmospheric Cerenkov Telescopes successfully detected very high energy (VHE; E>100 GeV) gamma-ray emission from a growing number of Active Galactic Nuclei (AGNs), mainly belonging to the…
Using gamma-ray data collected by the Astrorivelatore Gamma ad Immagini LEggero (AGILE) satellite over a period of almost one year (from 2007 July to 2008 June), we searched for pulsed signals from 35 potentially interesting radio pulsars,…
AGILE is a small gamma-ray astronomy satellite, with good spatial resolution, excellent timing capabilities and an unprecedented large field of view (~1/5 of the sky). It will be the next mission dedicated to high energy astrophysics in the…
BL Lac objects of the intermediate subclass (IBLs) are known to emit a substantial fraction of their power in the energy range 0.1--10 GeV. Detecting gamma-ray emission from such sources provides therefore a direct probe of the emission…
AGILE pointed observations performed from July 9, 2007 to October 30, 2009 cover a very large time interval, with a \gamma-ray dataset useful to perform studies of medium to high brightness galactic sources in the 30 MeV -- 50 GeV energy…
Active galactic nuclei (AGNs) make up about 35 per cent of the more than 250 sources detected in very-high-energy (VHE) gamma rays to date with Imaging Atmospheric Cherenkov Telescopes. Apart from four nearby radio galaxies and two AGNs of…
We present the results of a series of optical, UV, X-ray and gamma-ray observations of the BL Lac object S50716+714 carried out by the Swift and AGILE satellites in late 2007 when this blazar was flaring close to its historical maximum at…
We present the discovery of PSO J030947.49+271757.31, the radio brightest (23.7 mJy at 1.4 GHz) active galactic nucleus (AGN) at z>6.0. It was selected by cross-matching the NRAO VLA Sky Survey and the Panoramic Survey Telescope and Rapid…
AGILE is a small gamma-ray astronomy satellite mission of the Italian Space Agency dedicated to high-energy astrophysics launched in 2007 April. Its 1 microsecond absolute time tagging capability coupled with a good sensitivity in the 30…
We present the discovery of very high energy (VHE) gamma-ray emission from the high-frequency-peaked BL Lac object 1ES 0806+524 (z=0.138) and the intermediate-frequency-peaked BL Lac object W Comae (z=0.102) with VERITAS. VHE emission was…
3C 454.3 is the most variable and intense extragalactic gamma-ray blazar detected by AGILE and Fermi during the last 4 years. This remarkable source shows extreme flux variability (about a fact or of 20) on a time-scale of 24-48 hours, as…