Related papers: BATSE observations of BL Lac Objects

Very high-energy observations of the two high-frequency peaked BL Lac objects 1ES 1218+304 and H 1426+428

We present results of very-high-energy gamma-ray observations (E > 160 GeV) of two high-frequency-peaked BL Lac (HBL) objects, 1ES 1218+304 and H 1426+428, with the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE). Both sources…

High Energy Astrophysical Phenomena · Physics 2011-07-28 C. Mueller , N. Akhter , J. Ball , D. A. Bramel , J. Carson , C. E. Covault , D. Driscoll , P. Fortin , D. M. Gingrich , D. S. Hanna , A. Jarvis , J. Kildea , T. Lindner , R. Mukherjee , R. A. Ong , K. Ragan , R. A. Scalzo , D. A. Williams , J. Zweerink

Searching for Unmodeled Sources Using the Earth Occultation Data from the Fermi GBM

Employing the 12 NaI detectors in the Fermi GBM, the Earth Occultation Technique (EOT) can be used to measure the fluxes of x-ray and gamma-ray sources. Each time a source passes behind the Earth (or emerges from behind the Earth), a…

High Energy Astrophysical Phenomena · Physics 2011-11-03 James Rodi , Gary L. Case , Michael L. Cherry , Ascension Camero-Arranz , Mark H. Finger , Peter Jenke , Colleen A. Wilson-Hodge , Vandiver Chaplin

Multi-wavelength Observations of H 2356-309

AIMS: The properties of the broad-band emission from the high-frequency peaked BL Lac H 2356-309 (z=0.165) are investigated. METHODS: Very High Energy (VHE; E > 100 GeV) observations of H 2356-309 were performed with the High Energy…

High Energy Astrophysical Phenomena · Physics 2015-05-18 HESS Collaboration , A. Abramowski , F. Acero , F. Aharonian , A. G. Akhperjanian , G. Anton , U. Barres de Almeida , A. R. Bazer-Bachi , Y. Becherini , B. Behera , W. Benbow , K. Bernloehr , A. Bochow , C. Boisson , J. Bolmont , V. Borrel , J. Brucker , F. Brun , P. Brun , R. Buehler , T. Bulik , I. Buesching , T. Boutelier , P. M. Chadwick , A. Charbonnier , R. C. G. Chaves , A. Cheesebrough , J. Conrad , L. -M. Chounet , A. C. Clapson , G. Coignet , L. Costamante , M. Dalton , M. K. Daniel , I. D. Davids , B. Degrange , C. Deil , H. J. Dickinson , A. Djannati-Atai , W. Domainko , L. O'C. Drury , F. Dubois , G. Dubus , J. Dyks , M. Dyrda , K. Egberts , P. Eger , P. Espigat , L. Fallon , C. Farnier , S. Fegan , F. Feinstein , M. V. Fernandes , A. Fiasson , A. Foerster , G. Fontaine , M. Fuessling , S. Gabici , Y. A. Gallant , L. Gerard , D. Gerbig , B. Giebels , J. F. Glicenstein , B. Glueck , P. Goret , D. Goering , D. Hampf , M. Hauser , S. Heinz , G. Heinzelmann , G. Henri , G. Hermann , J. A. Hinton , A. Hoffmann , W. Hofmann , P. Hofverberg , M. Holleran , S. Hoppe , D. Horns , A. Jacholkowska , O. C. de Jager , C. Jahn , I. Jung , K. Katarzynski , U. Katz , S. Kaufmann , M. Kerschhaggl , D. Khangulyan , B. Khelifi , D. Keogh , D. Klochkov , W. Kluzniak , T. Kneiske , Nu. Komin , K. Kosack , R. Kossakowski , G. Lamanna , J. -P. Lenain , T. Lohse , C. -C. Lu , V. Marandon , A. Marcowith , J. Masbou , D. Maurin , T. J. L. McComb , M. C. Medina , J. Mehault , R. Moderski , E. Moulin , M. Naumann-Godo , M. de Naurois , D. Nedbal , D. Nekrassov , N. Nguyen , B. Nicholas , J. Niemiec , S. J. Nolan , S. Ohm , J-F. Olive , E. de Ona Wilhelmi , B. Opitz , K. J. Orford , M. Ostrowski , M. Panter , M. Paz Arribas , G. Pedaletti , G. Pelletier , P. -O. Petrucci , S. Pita , G. Puehlhofer , M. Punch , A. Quirrenbach , B. C. Raubenheimer , M. Raue , S. M. Rayner , O. Reimer , M. Renaud , R. de los Reyes , F. Rieger , J. Ripken , L. Rob , S. Rosier-Lees , G. Rowell , B. Rudak , C. B. Rulten , J. Ruppel , F. Ryde , V. Sahakian , A. Santangelo , R. Schlickeiser , F. M. Schoeck , A. Schoenwald , U. Schwanke , S. Schwarzburg , S. Schwemmer , A. Shalchi , I. Sushch , M. Sikora , J. L. Skilton , H. Sol , L. Stawarz , R. Steenkamp , C. Stegmann , F. Stinzing , A. Szostek , P. H. Tam , J. -P. Tavernet , R. Terrier , O. Tibolla , M. Tluczykont , K. Valerius , C. van Eldik , G. Vasileiadis , C. Venter , L. Venter , J. P. Vialle , A. Viana , P. Vincent , M. Vivier , H. J. Voelk , F. Volpe , S. Vorobiov , S. J. Wagner , M. Ward , A. A. Zdziarski , A. Zech , H. -S. Zechlin

Revisiting the Earth's atmospheric scattering of X-ray/$\gamma$-rays and its effect on space observation: Implication for GRB spectral analysis

A considerable fraction of incident high-energy photons from astrophysical transients such as Gamma-Ray Bursts (GRBs) is Compton scattered by the Earth's atmosphere. These photons, sometimes referred to as the "reflection component",…

High Energy Astrophysical Phenomena · Physics 2021-05-21 Sourav Palit , Akash Anumarlapudi , Varun Bhalerao

The Nature of $\gamma$-ray Variability in Blazars

We present an in-depth and systematic variability study of a sample of 20 powerful blazars, including 12 BL Lacs and 8 flat spectrum radio quasars, applying various analysis tools such as flux distribution, symmetry analysis, and time…

High Energy Astrophysical Phenomena · Physics 2020-03-18 Gopal Bhatta , Niraj Dhital

Blazar Compton efficiencies: Fermi, external photons and the Sequence

The Fermi-LAT survey provides a large sample of blazars selected on the strength of their inverse Compton emission. We cross-correlate the first Fermi-LAT catalogue with the CRATES radio catalogue and use this sample to investigate whether…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-28 J. A. Gupta , I. W. A. Browne , M. W. Peel

X-ray properties of an Unbiased Hard X-ray Detected Sample of AGN

The SWIFT gamma ray observatory's Burst Alert Telescope (BAT) has detected a sample of active galactic nuclei (AGN) based solely on their hard X-ray flux (14-195 keV). In this paper, we present for the first time {\it XMM-Newton} X-ray…

Astrophysics · Physics 2009-11-13 Lisa M. Winter , Richard F. Mushotzky , Jack Tueller , Craig Markwardt

Testing the Randomness in the Sky-Distribution of Gamma-Ray Bursts

We studied the complete randomness of the angular distribution of gamma-ray bursts (GRBs) detected by BATSE. Since GRBs seem to be a mixture of objects of different physical nature we divided the BATSE sample into 5 subsamples (short1,…

Astrophysics · Physics 2009-11-13 R. Vavrek , L. G. Balázs , A. Mészáros , I. Horváth , Z. Bagoly

Detection and Imaging of the Crab Nebula with the Nuclear Compton Telescope

The Nuclear Compton Telescope (NCT) is a balloon-borne Compton telescope designed for the study of astrophysical sources in the soft gamma-ray regime (200 keV--20 MeV). NCT's ten high-purity germanium crossed-strip detectors measure the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 M. S. Bandstra , E. C. Bellm , S. E. Boggs , D. Perez-Becker , A. Zoglauer , H. -K. Chang , J. -L. Chiu , J. -S. Liang , Y. -H. Chang , Z. -K. Liu , W. -C. Hung , M. -H. A. Huang , S. J. Chiang , R. -S. Run , C. -H. Lin , M. Amman , P. N. Luke , P. Jean , P. von Ballmoos , C. B. Wunderer

Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR, Swift, and Ground-Based Multi-wavelength Observations

We report the results of a multi-band observing campaign on the famous blazar 3C 279 conducted during a phase of increased activity from 2013 December to 2014 April, including first observations of it with NuSTAR. The $\gamma$-ray emission…

High Energy Astrophysical Phenomena · Physics 2015-07-15 M. Hayashida , K. Nalewajko , G. M. Madejski , M. Sikora , R. Itoh , M. Ajello , R. D. Blandford , S. Buson , J. Chiang , Y. Fukazawa , A. K. Furniss , C. M. Urry , I. Hasan , F. A. Harrison , D. M. Alexander , M. Baloković , D. Barret , S. E. Boggs , F. E. Christensen , W. W. Craig , K. Forster , P. Giommi , B. Grefenstette , C. Hailey , A. Hornstrup , T. Kitaguchi , J. E. Koglin , K. K. Madsen , P. H. Mao , H. Miyasaka , K. Mori , M. Perri , M. J. Pivovaroff , S. Puccetti , V. Rana , D. Stern , G. Tagliaferri , N. J. Westergaard , W. W. Zhang , A. Zoglauer , M. A. Gurwell , M. Uemura , H. Akitaya , K. S. Kawabata , K. Kawaguch , Y. Kanda , Y. Moritani , K. Takaki , T. Ui , M. Yoshida , A. Agarwal , A. C. Gupta

Results from GROCSE: A Real-time Search for Gamma Ray Burst Optical Counterparts

The Gamma-Ray Optical Counterpart Search Experiment (GROCSE) has searched for contemporaneous optical counterparts to gamma ray bursts (GRBs) using an automated rapidly slewing wide field of view optical telescope at Lawrence Livermore…

Astrophysics · Physics 2008-02-03 Brian Lee , Carl Akerlof , David Band , Scott Barthelmy , Paul Butterworth , Thomas Cline , Donald Ferguson , Neil Gehrels , Kevin Hurley

An emerging population of BL Lacs with extreme properties: towards a class of EBL and cosmic magnetic field probes?

High energy observations of extreme BL Lac objects, such as 1ES 0229+200 or 1ES 0347-121, recently focused interest both for blazar and jet physics and for the implication on the extragalactic background light and intergalactic magnetic…

High Energy Astrophysical Phenomena · Physics 2015-06-25 Giacomo Bonnoli , Fabrizio Tavecchio , Gabriele Ghisellini , Tullia Sbarrato

Inferring the Spatial and Energy Distribution of Gamma Ray Burst Sources. II. Isotropic Models

We use Bayesian methods to analyze the distribution of gamma ray burst intensities reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts, presuming the distribution of burst sources (``bursters'') is isotropic. We study both…

Astrophysics · Physics 2009-10-30 Thomas J. Loredo , Ira M. Wasserman

H.E.S.S. Observations of the Crab during its March 2013 GeV Gamma-Ray Flare

Context. On March 4, 2013, the Fermi-LAT and AGILE reported a flare from the direction of the Crab Nebula in which the high-energy (HE; E > 100 MeV) flux was six times above its quiescent level. Simultaneous observations in other energy…

High Energy Astrophysical Phenomena · Physics 2014-02-20 H. E. S. S. Collaboration , A. Abramowski , F. Aharonian , F. Ait Benkhali , A. G. Akhperjanian , E. Angüner , G. Anton , S. Balenderan , A. Balzer , A. Barnacka , Y. Becherini , J. Becker Tjus , K. Bernlöhr , E. Birsin , E. Bissaldi , J. Biteau , M. Böttcher , C. Boisson , J. Bolmont , P. Bordas , J. Brucker , F. Brun , P. Brun , T. Bulik , S. Carrigan , S. Casanova , M. Cerruti , P. M. Chadwick , R. Chalme-Calvet , R. C. G. Chaves , A. Cheesebrough , M. Chrétien , S. Colafrancesco , G. Cologna , J. Conrad , C. Couturier , Y. Cui , M. Dalton , M. K. Daniel , I. D. Davids , B. Degrange , C. Deil , P. deWilt , H. J. Dickinson , A. Djannati-Ataï , W. Domainko , L. O'C. Drury , G. Dubus , K. Dutson , J. Dyks , M. Dyrda , T. Edwards , K. Egberts , P. Eger , P. Espigat , C. Farnier , S. Fegan , F. Feinstein , M. V. Fernandes , D. Fernandez , A. Fiasson , G. Fontaine , A. Förster , M. Füßling , M. Gajdus , Y. A. Gallant , T. Garrigoux , G. Giavitto , B. Giebels , J. F. Glicenstein , M. -H. Grondin , M. Grudzińska , S. Häffner , J. Hahn , J. Harris , G. Heinzelmann , G. Henri , G. Hermann , O. Hervet , A. Hillert , J. A. Hinton , W. Hofmann , P. Hofverberg , M. Holler , D. Horns , A. Jacholkowska , C. Jahn , M. Jamrozy , M. Janiak , F. Jankowsky , I. Jung , M. A. Kastendieck , K. Katarzyński , U. Katz , S. Kaufmann , B. Khélifi , M. Kieffer , S. Klepser , D. Klochkov , W. Kluźniak , T. Kneiske , D. Kolitzus , Nu. Komin , K. Kosack , S. Krakau , F. Krayzel , P. P. Krüger , H. Laffon , G. Lamanna , J. Lefaucheur , A. Lemière , M. Lemoine-Goumard , J. -P. Lenain , D. Lennarz , T. Lohse , A. Lopatin , C. -C. Lu , V. Marandon , A. Marcowith , R. Marx , G. Maurin , N. Maxted , M. Mayer , T. J. L. McComb , J. Méhault , P. J. Meintjes , U. Menzler , M. Meyer , R. Moderski , M. Mohamed , E. Moulin , T. Murach , C. L. Naumann , M. de Naurois , J. Niemiec , S. J. Nolan , L. Oakes , S. Ohm , E. de Oña Wilhelmi , B. Opitz , M. Ostrowski , I. Oya , M. Panter , R. D. Parsons , M. Paz Arribas , N. W. Pekeur , G. Pelletier , J. Perez , P. -O. Petrucci , B. Peyaud , S. Pita , H. Poon , G. Pühlhofer , M. Punch , A. Quirrenbach , S. Raab , M. Raue , A. Reimer , O. Reimer , M. Renaud , R. de los Reyes , F. Rieger , L. Rob , C. Romoli , S. Rosier-Lees , G. Rowell , B. Rudak , C. B. Rulten , V. Sahakian , D. A. Sanchez , A. Santangelo , R. Schlickeiser , F. Schüssler , A. Schulz , U. Schwanke , S. Schwarzburg , S. Schwemmer , H. Sol , G. Spengler , F. Spies , Ł. Stawarz , R. Steenkamp , C. Stegmann , F. Stinzing , K. Stycz , I. Sushch , A. Szostek , J. -P. Tavernet , T. Tavernier , A. M. Taylor , R. Terrier , M. Tluczykont , C. Trichard , K. Valerius , C. van Eldik , B. van Soelen , G. Vasileiadis , C. Venter , A. Viana , P. Vincent , H. J. Völk , F. Volpe , M. Vorster , T. Vuillaume , S. J. Wagner , P. Wagner , M. Ward , M. Weidinger , Q. Weitzel , R. White , A. Wierzcholska , P. Willmann , A. Wörnlein , D. Wouters , V. Zabalza , M. Zacharias , A. Zajczyk , A. A. Zdziarski , A. Zech , H. -S. Zechlin

Exploring Short-Term Optical Variability of Blazars Using $\textit{TESS}$

We present a first systematic time series study of a sample of blazars observed by the Transiting Exoplanet Survey Satellite $\textit{TESS}$ spacecraft. By cross matching the positions of the sources in the TESS observations with those from…

High Energy Astrophysical Phenomena · Physics 2022-11-23 Vivek Reddy Pininti , Gopal Bhatta , Sagarika Paul , Aman Kumar , Aayushi Rajgor , Rahul Barnwal , Sarvesh Gharat

STACEE Observations of 1ES 1218+304

We present the analysis and results of recent high-energy gamma-ray observations of the high energy-peaked BL Lac (HBL) object 1ES 1218+304 with the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE). 1ES 1218+304 is an X-ray…

Astrophysics · Physics 2007-10-24 STACEE Collaboration , R. Mukherjee , N. Akhter , J. Ball , J. E. Carson , C. E. Covault , D. D. Driscoll , P. Fortin , D. M. Gingrich , D. S. Hanna , A. Jarvis , J. Kildea , T. Lindner , C. Mueller , R. A. Ong , K. Ragan , D. A. Williams , J. Zweerink

RXTE all-sky slew survey. Catalog of X-ray sources at |b|>10deg

We report results of a serendipitous hard X-ray (3--20 keV), nearly all-sky (|b|>10deg) survey based on RXTE/PCA observations performed during satellite reorientations in 1996--2002. The survey is 80% (90%) complete to a 4$\sigma$ limiting…

Astrophysics · Physics 2009-11-10 M. Revnivtsev , S. Sazonov , K. Jahoda , M. Gilfanov

Discovery of VHE \gamma-ray emission and multi-wavelength observations of the BL Lac object 1RXS J101015.9-311909

1RXS J101015.9-311909 is a galaxy located at a redshift of z=0.14 hosting an active nucleus belonging to the class of bright BL Lac objects. Observations at high (HE, E > 100 MeV) and very high (VHE, E > 100 GeV) energies provide insights…

High Energy Astrophysical Phenomena · Physics 2015-06-04 HESS Collaboration , A. Abramowski , F. Acero , F. Aharonian , A. G. Akhperjanian , G. Anton , A. Balzer , A. Barnacka , Y. Becherini , J. Becker , K. Bernlöhr , E. Birsin , J. Biteau , A. Bochow , C. Boisson , J. Bolmont , P. Bordas , J. Brucker , F. Brun , P. Brun , T. Bulik , I. Büsching , S. Carrigan , S. Casanova , M. Cerruti , P. M. Chadwick , A. Charbonnier , R. C. G. Chaves , A. Cheesebrough , G. Cologna , J. Conrad , M. Dalton , M. K. Daniel , I. D. Davids , B. Degrange , C. Deil , H. J. Dickinson , A. Djannati-Ataï , W. Domainko , L. O'C. Drury , G. Dubus , K. Dutson , J. Dyks , M. Dyrda , K. Egberts , P. Eger , P. Espigat , L. Fallon , S. Fegan , F. Feinstein , M. V. Fernandes , A. Fiasson , G. Fontaine , A. Förster , M. Füßling , Y. A. Gallant , H. Gast , L. Gérard , D. Gerbig , B. Giebels , J. F. Glicenstein , B. Glück , D. Göring , S. Häffner , J. D. Hague , J. Hahn , D. Hampf , J. Harris , M. Hauser , S. Heinz , G. Heinzelmann , G. Henri , G. Hermann , A. Hillert , J. A. Hinton , W. Hofmann , P. Hofverberg , M. Holler , D. Horns , A. Jacholkowska , O. C. de Jager , C. Jahn , M. Jamrozy , I. Jung , M. A. Kastendieck , K. Katarzyński , U. Katz , S. Kaufmann , D. Keogh , B. Khélifi , D. Klochkov , W. Kluźniak , T. Kneiske , Nu. Komin , K. Kosack , R. Kossakowski , F. Krayzel , H. Laffon , G. Lamanna , J. -P. Lenain , D. Lennarz , T. Lohse , A. Lopatin , C. -C. Lu , V. Marandon , A. Marcowith , J. Masbou , N. Maxted , M. Mayer , T. J. L. McComb , M. C. Medina , J. Méhault , R. Moderski , M. Mohamed , E. Moulin , C. L. Naumann , M. Naumann-Godo , M. de Naurois , D. Nedbal , D. Nekrassov , N. Nguyen , B. Nicholas , J. Niemiec , S. J. Nolan , S. Ohm , E. de Oña Wilhelmi , B. Opitz , M. Ostrowski , I. Oya , M. Panter , M. Paz Arribas , N. W. Pekeur , G. Pelletier , J. Perez , P. -O. Petrucci , B. Peyaud , S. Pita , G. Pühlhofer , M. Punch , A. Quirrenbach , M. Raue , S. M. Rayner , A. Reimer , O. Reimer , M. Renaud , R. de los Reyes , F. Rieger , J. Ripken , L. Rob , S. Rosier-Lees , G. Rowell , B. Rudak , C. B. Rulten , V. Sahakian , D. A. Sanchez , A. Santangelo , R. Schlickeiser , A. Schulz , U. Schwanke , S. Schwarzburg , S. Schwemmer , F. Sheidaei , J. L. Skilton , H. Sol , G. Spengler , Ł. Stawarz , R. Steenkamp , C. Stegmann , F. Stinzing , K. Stycz , I. Sushch , A. Szostek , J. -P. Tavernet , R. Terrier , M. Tluczykont , K. Valerius , C. van Eldik , G. Vasileiadis , C. Venter , A. Viana , P. Vincent , H. J. Völk , F. Volpe , S. Vorobiov , M. Vorster , S. J. Wagner , M. Ward , R. White , A. Wierzcholska , M. Zacharias , A. Zajczyk , A. A. Zdziarski , A. Zech , H. -S. Zechlin

On the cosmological evolution of BL Lacs

We study the cosmological evolution of BL Lac objects by applying the Ve/Va analysis to a new sample of 55 objects presented for the first time in this paper. This sample has been selected from the 239 sources with the brightest X-ray flux…

Astrophysics · Physics 2009-11-07 A. Caccianiga , T. Maccacaro , A. Wolter , R. Della Ceca , I. M. Gioia

BL Lacertae under the Flare of 2024: Probing Temporal and Spectral Dynamics

In October 2024, the object BL Lacertae experienced the brightest flaring event in gamma-ray ($>$100 MeV) with a historically bright $\gamma$-ray flux of $\sim$2.59 $\times 10^{-5}$ erg cm$^{-2}$ s$^{-1}$ with a detection of a 175.7 GeV…

High Energy Astrophysical Phenomena · Physics 2025-07-08 Joysankar Majumdar , Sakshi Maurya , Raj Prince