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The origin of the soft gamma-ray (200 keV - 1 MeV) galactic ridge emission is one of the long-standing mysteries in the field of high-energy astrophysics. Population studies at lower energies have shown that emission from accreting compact…

We present the Second Palermo Swift-BAT hard X-ray catalogue obtained by analysing data acquired in the first 54 months of the Swift mission. Using our software dedicated to the analysis of data from coded mask telescopes, we analysed the…

High Energy Astrophysical Phenomena · Physics 2015-05-19 G. Cusumano , V. La Parola , A. Segreto , C. Ferrigno , A. Maselli , B. Sbarufatti , P. Romano , G. Chincarini , P. Giommi , N. Masetti , A. Moretti , P. Parisi , G. Tagliaferri

While supernova remnants (SNRs) are widely thought to be powerful cosmic-ray accelerators, indirect evidence comes from a small number of well-studied cases. Here we systematically determine the gamma-ray emission detected by the Fermi…

High Energy Astrophysical Phenomena · Physics 2015-07-14 F. de Palma , T. J. Brandt , J. W. Hewitt , G. Johannesson , L. Tibaldo

We report the discovery of high-energy (E>100 MeV) gamma-ray emission from NGC 1275, a giant elliptical galaxy lying at the center of the Perseus cluster of galaxies, based on observations made with the Large Area Telescope (LAT) of the…

High Energy Astrophysical Phenomena · Physics 2012-08-27 LAT Collaboration , A. A. Abdo , H. D. Aller , M. F. Aller , K. I. Kellermann , Y. Y. Kovalev , Y. A. Kovalev , M. L. Lister , A. B. Pushkarev

We investigate radiatively inefficient accretion flow models for Sgr A*, the supermassive black hole in our Galactic Center, in light of new observational constraints. Confirmation of linear polarization in the submm emission argues for…

Astrophysics · Physics 2009-11-07 Feng Yuan , Eliot Quataert , Ramesh Narayan

J191213.72-441045.1 is a binary system composed of a white dwarf and an M-dwarf in a 4.03-hour orbit. It shows emission in radio, optical, and X-ray, all modulated at the white dwarf spin period of 5.3 min, as well as various orbital…

We present an analysis of gamma-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region around SNR S147 (G180.0-1.7). A spatially extended gamma-ray source detected in an energy range…

The Broad Line Radio Galaxy 3C 111, characterized by a Fanaroff-Riley II (FRII) radio morphology, is one of the sources of the Misaligned Active Galactic Nuclei sample, consisting of Radio Galaxies and Steep Spectrum Radio Quasars, recently…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Paola Grandi , Eleonora Torresi , Carlo Stanghellini

The process of energy release in the magnetosphere of a fast rotating, magnetized white dwarf can be explained in terms of the canonical spin-powered pulsar model. Applying this model to the white dwarf companion of the low mass close…

Astrophysics · Physics 2009-11-11 N. R. Ikhsanov , P. L. Biermann

We analyze a large collection of RXTE archive data from April 1997 to August 2003 of the bright X-ray source Scorpius X-1 in order to study the broadband spectral evolution of the source for different values of the inferred mass accretion…

Astrophysics · Physics 2009-11-13 A. D'Aí , P. Zycki , T. Di Salvo , R. Iaria , G. Lavagetto , N. R. Robba

(Abridged) We have conducted a detailed investigation of the broad-band spectral properties of the \gamma-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi gamma-ray spectra with…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 A. A. Abdo , M. Ackermann , M. Ajello , M. Axelsson , L. Baldini , J. Ballet , G. Barbiellini , D. Bastieri , B. M. Baughman , K. Bechtol , R. Bellazzini , B. Berenji , R. D. Blandford , E. D. Bloom , E. Bonamente , A. Borgland , J. Bregeon , A. Brez , M. Brigida , P. Bruel , T. H. Burnett , S. Buson , G. A. Caliandro , R. A. Cameron , P. A. Caraveo , J. M. Casandjian , E. Cavazzuti , C. Cecchi , O. Celik , E. Charles , S. Chaty , A. Chekhtman , J. Chiang , S. Ciprini , R. Claus , J. Cohen-Tanugi , S. Colafrancesco , L. R. Cominsky , J. Conrad , L. Costamante , S. Cutini , C. D. Dermer , A. de Angelis , F. de Palma , S. W. Digel , E. do Couto e Silva , P. S. Drell , R. Dubois , D. Dumora , C. Farnier , C. Favuzzi , S. J. Fegan , W. B. Focke , P. Fortin , M. Frailis , L. Fuhrmann , Y. Fukazawa , S. Funk , P. Fusco , F. Gargano , D. Gasparrini , N. Gehrels , S. Germani , B. Giebels , N. Giglietto , P. Giommi , F. Giordano , T. Glanzman , G. Godfrey , I. A. Grenier , J. E. Grove , L. Guillemot , S. Guiriec , D. Hadasch , Y. Hanabata , A. K. Harding , M. Hayashida , E. Hays , S. E. Healey , D. Horan , R. E. Hughes , R. Itoh , M. S. Jackson , G. Johannesson , A. S. Johnson , W. N. Johnson , M. Kadler , T. Kamae , H. Katagiri , J. Kataoka , N. Kawai , M. Kerr , J. Knodlseder , M. L. Kocian , M. Kuss , J. Lande , L. Latronico , F. Longo , F. Loparco , B. Lott , M. N. Lovellette , P. Lubrano , G. M. Madejski , A. Makeev , W. Max-Moerbeck , M. N. Mazziotta , W. McConville , J. E. McEnery , C. Meurer , P. F. Michelson

We report the results from our analysis of a large set of archival data acquired with the X-ray telescope (XRT) onboard Swift, covering the sky region surrounding objects from the first Fermi Large Area Telescope (LAT) catalogue of…

High Energy Astrophysical Phenomena · Physics 2015-09-16 R. Landi , L. Bassani , J. B. Stephen , N. Masetti , A. Malizia , P. Ubertini

4FGL J0935.3+0901 is a gamma-ray source detected by the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope. We have conducted detailed analysis of the LAT data for this source and multi-wavelength studies of the source…

We explain the results of Yu et al. (2015b) of the novel sharpness angle measurement to a large number of spectra obtained from the Fermi gamma-ray burst monitor. The sharpness angle is compared to the values obtained from various…

The Fermi Gamma-ray Space Telescope, a key mission in multiwavelength and multimessenger studies, has been surveying the gamma-ray sky from its low-Earth orbit since 2008. Its two scientific instruments, the Gamma-ray Burst Monitor (GBM)…

High Energy Astrophysical Phenomena · Physics 2023-04-05 David J. Thompson , Colleen A. Wilson-Hodge

We present a catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), during the first 11 months of the science phase of the mission,…

High Energy Astrophysical Phenomena · Physics 2015-05-18 LAT Collaboration

We present Rossi X-ray Timing Explorer, monitoring observations of the Seyfert 2 galaxy Markarian 3 spanning a 200 day period during which time the source flux varied by a factor $\sim 2$ in the 4-20 keV bandpass. In broad agreement with…

We report on a recent (2016-2018) enhancement of the GeV emission from the SN 1987A region as observed with Fermi/LAT. The observed signal is characterised by a power-law spectrum with a slope of 2.1 +/- 0.2 and is detected only at energies…

High Energy Astrophysical Phenomena · Physics 2019-03-08 Denys Malyshev , Gerd Pühlhofer , Andrea Santangelo , Jacco Vink

The super-massive 4 million solar mass black hole (SMBH) SgrA* shows variable emission from the millimeter to the X-ray domain. A detailed analysis of the infrared light curves allows us to address the accretion phenomenon in a statistical…