English
Related papers

Related papers: Evaluating the Maximum Likelihood Method for Detec…

200 papers

The AGILE satellite detected several episodes of transient gamma-ray emission from Cygnus X-3. Cross-correlating the AGILE light curve with both X-ray and radio monitoring data, we found that the main events of gamma-ray activity were…

High Energy Astrophysical Phenomena · Physics 2019-08-14 G. Piano , M. Tavani , V. Vittorini , A. Giuliani

We present the results of a search for cosmic ray point sources at energies above 40 EeV in the combined data sets recorded by the AGASA and HiRes stereo experiments. The analysis is based on a maximum likelihood ratio test using the…

Astrophysics · Physics 2008-11-26 s Eye Collaboration , G. R. Farrar

We use the Very Long Baseline Array to conduct high precision astrometry of a sample of 33 compact, flat spectrum, variable radio sources in the direction of the Galactic plane (Becker et al. 2010). Although Becker et al. (2010) ruled out a…

High Energy Astrophysical Phenomena · Physics 2022-10-12 P. Atri , J. C. A. Miller-Jones , A. Bahramian , R. M. Plotkin , T. J. Maccarone , B. Marcote , C. O. Heinke , G. R. Sivakoff , A. Ginsburg , L. Chomiuk

The reliability of detecting source variability in sparsely and irregularly sampled X-ray light curves is investigated. This is motivated by the unprecedented survey capabilities of eROSITA onboard SRG, providing light curves for many…

High Energy Astrophysical Phenomena · Physics 2022-05-18 Johannes Buchner , Thomas Boller , David Bogensberger , Adam Malyali , Kirpal Nandra , Joern Wilms , Tom Dwelly , Teng Liu

We have searched for ultra-long (> 100 s) gamma-ray transients in the data from the anticoincidence shield (ACS) of the SPI gamma-ray spectrometer onboard the INTEGRAL orbital observatory and classified them by machine learning methods. We…

We present a study of variability time scales in a large sample of Active Galactic Nuclei at several frequencies between 4.8 and 230 GHz. We investigate the differences of various AGN types and frequencies and correlate the measured time…

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…

High Energy Astrophysical Phenomena · Physics 2015-05-18 S. Vercellone , F. D'Ammando , V. Vittorini , I. Donnarumma , G. Pucella , M. Tavani , A. Ferrari , C. M. Raiteri , M. Villata , P. Romano , H. Krimm , A. Tiengo , A. W. Chen , G. Giovannini , T. Venturi , M. Giroletti , Y. Y. Kovalev , K. Sokolovsky , A. B. Pushkarev , M. L. Lister , A. Argan , G. Barbiellini , A. Bulgarelli , P. Caraveo , P. W. Cattaneo , V. Cocco , E. Costa , E. Del Monte , G. De Paris , G. Di Cocco , Y. Evangelista , M. Feroci , M. Fiorini , F. Fornari , T. Froysland , F. Fuschino , M. Galli , F. Gianotti , C. Labanti , I. Lapshov , F. Lazzarotto , P. Lipari , F. Longo , A. Giuliani , M. Marisaldi , S. Mereghetti , A. Morselli , A. Pellizzoni , L. Pacciani , F. Perotti , G. Piano , P. Picozza , M. Pilia , M. Prest , M. Rapisarda , A. Rappoldi , S. Sabatini , P. Soffitta , E. Striani , M. Trifoglio , A. Trois , E. Vallazza , A. Zambra , D. Zanello , C. Pittori , F. Verrecchia , P. Santolamazza , P. Giommi , S. Colafrancesco , L. Salotti , I. Agudo , H. D. Aller , M. F. Aller , A. A. Arkharov , U. Bach , R. Bachev , P. Beltrame , E. Benitez , M. Boettcher , C. S. Buemi , P. Calcidese , D. Capezzali , D. Carosati , W. P. Chen , D. Da Rio , A. Di Paola , M. Dolci , D. Dultzin , E. Forne , J. L. Gomez , M. A. Gurwell , V. A. Hagen-Thorn , A. Halkola , J. Heidt , D. Hiriart , T. Hovatta , H. Y. Hsiao , S. G. Jorstad , G. Kimeridze , T. S. Konstantinova , E. N. Kopatskaya , E. Koptelova , O. Kurtanidze , A. Lahteenmaki , V. M. Larionov , P. Leto , R. Ligustri , E. Lindfors , J. M. Lopez , A. P. Marscher , R. Mujica , M. Nikolashvili , K. Nilsson

Gamma-ray Astronomy studies cosmic accelerators through their electromagnetic radiation in the energy range between ~100 MeV and ~100 TeV. The present most sensitive observations in this energy band are performed, from space, by the Large…

High Energy Astrophysical Phenomena · Physics 2011-11-29 Javier Rico

As the sensitivity and observing time of gravitational-wave detectors increase, a more diverse range of signals is expected to be observed from a variety of sources. Especially, long-lived gravitational-wave transients have received…

Instrumentation and Methods for Astrophysics · Physics 2021-11-24 Adrian Macquet , Marie-Anne Bizouard , Nelson Christensen , Michael Coughlin

Many gamma-ray bursts (GRBs) have been observed from radio wavelengths, and a few at very-high energies (VHEs, > 100GeV). The HAWC gamma-ray observatory is well suited to study transient phenomena at VHEs due to its large field of view and…

Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an…

Astrophysics · Physics 2009-06-23 D. J. Thompson

We present the results of multi-year gamma-ray observations by the AGILE satellite of the black hole binary system Cygnus X-1. In a previous investigation we focused on gamma-ray observations of Cygnus X-1 in the hard state during the…

We studied the problematic of uncertainties in the diffuse gamma radiation apparent in stacking analysis of EGRET data at low Galactic latitudes. Subsequently, we co-added maps of counts, exposure and diffuse background, and residuals, in…

Astrophysics · Physics 2008-11-26 Analia N. Cillis , Olaf Reimer , Diego F. Torres

AGILE (Astrorivelatore Gamma ad Immagini LEggero) has been a unique and hugely successful mission of Italian Space Agency (ASI), built and operated with the programmatic and technical support of the National Institute for Astrophysics…

We report the results of a low frequency radio variability and slow transient search using archival observations from the Very Long Array. We selected six 325 MHz radio observations from the spring of 2006, each centered on the…

High Energy Astrophysical Phenomena · Physics 2015-06-04 T. R. Jaeger , S. D. Hyman , N. E. Kassim , T. J. W. Lazio

We describe an ongoing effort using the Fermi Large Area Telescope to search for gamma-ray emission from a source sample derived from published surveys of variable or transient galactic radio sources.

High Energy Astrophysical Phenomena · Physics 2013-05-27 C. R. Shrader , D. J. Macomb

AGILE is an Italian Space Agency (ASI) space mission launched in 2007 to study X-ray and gamma-ray phenomena in the energy range from $\sim$20 keV to $\sim$10 GeV. The AGILE AntiCoincidence System (ACS) detects hard-X photons in the 50 -…

High Energy Astrophysical Phenomena · Physics 2024-04-03 N. Parmiggiani , A. Bulgarelli , A. Macaluso , A. Ursi , L. Castaldini , A. Di Piano , R. Falco , V. Fioretti , G. Panebianco , C. Pittori , M. Tavani

We analyzed data obtained by the SPI telescope onboard the INTEGRAL observatory to search for short transient events with a duration from 1 ms to a few tens of seconds. An algorithm for identifying gamma-ray events against the background of…

High Energy Astrophysical Phenomena · Physics 2015-06-19 P. Yu. Minaev , A. S. Pozanenko , S. V. Molkov , S. A. Grebenev