J
J. A. Kennea
Researcher at Pennsylvania State University
Publications - 622
Citations - 29456
J. A. Kennea is an academic researcher from Pennsylvania State University. The author has contributed to research in topics: Gamma-ray burst & Neutron star. The author has an hindex of 70, co-authored 602 publications receiving 27048 citations. Previous affiliations of J. A. Kennea include Queen's University Belfast & University of Leicester.
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Journal ArticleDOI
The Swift X-ray telescope
David N. Burrows,Joanne E. Hill,John A. Nousek,J. A. Kennea,Alan A. Wells,J. P. Osborne,A. F. Abbey,A. P. Beardmore,K. Mukerjee,A. Short,Guido Chincarini,Sergio Campana,Oberto Citterio,Alberto Moretti,C. Pagani,Gianpiero Tagliaferri,Paolo Giommi,M. Capalbi,F. Tamburelli,Lorella Angelini,Giancarlo Cusumano,Heinrich Bräuninger,Wolfgang Burkert,Gisela Hartner +23 more
TL;DR: The Swift Gamma-Ray Explorer (XRT) as mentioned in this paper uses a mirror set built for JET-X and an XMM-Newton/EPIC MOS CCD detector to provide a sensitive broad-band (0.2-10 keV) X-ray imager with effective area of > 120 cm2 at 1.5 keV, field of view of 23.6 × 23. 6 arcminutes, and angular resolution of 18 arcseconds.
Journal ArticleDOI
The Swift X-ray Telescope
David N. Burrows,Joanne E. Hill,John A. Nousek,J. A. Kennea,Alan A. Wells,J. P. Osborne,A. F. Abbey,A. P. Beardmore,K. Mukerjee,A. Short,Guido Chincarini,Sergio Campana,Oberto Citterio,A. Moretti,C. Pagani,Gianpiero Tagliaferri,Paolo Giommi,M. Capalbi,F. Tamburelli,Lorella Angelini,G. Cusumano,Heinrich W. Braeuninger,Wolfgang Burkert,Gisela Hartner +23 more
TL;DR: The Swift Gamma-Ray Explorer (XRT) as mentioned in this paper uses a mirror set built for JET-X and an XMM/EPIC MOS CCD detector to provide a sensitive broad-band (0.2-10 keV) X-ray imager with effective area of > 120 cm^2 at 1.5 keV, field of view of 23.6 x23.6 arcminutes, and angular resolution of 18 arcseconds (HPD).
Journal ArticleDOI
Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
Phil Evans,A. P. Beardmore,K. L. Page,J. P. Osborne,P. T. O'Brien,Richard Willingale,R. L. C. Starling,David N. Burrows,Olivier Godet,L. Vetere,Judith Racusin,M. R. Goad,Klaas Wiersema,Lorella Angelini,Milvia Capalbi,G. Chincarini,G. Chincarini,Neil Gehrels,J. A. Kennea,Raffaella Margutti,Raffaella Margutti,D. C. Morris,D. C. Morris,C. J. Mountford,C. Pagani,M. Perri,P. Romano,Nial R. Tanvir +27 more
TL;DR: A homogeneous X-rays analysis of all 318 gamma-ray bursts detected by the X-ray telescope (XRT) on the Swift satellite up to 2008 July 23 is presented; this represents the largest sample ofX-ray GRB data published to date.
Journal ArticleDOI
The spectral energy distribution of fermi bright blazars
A. A. Abdo,A. A. Abdo,Markus Ackermann,Ivan Agudo,Marco Ajello,Hugh D. Aller,Margo F. Aller,Emmanouil Angelakis,A. A. Arkharov,Magnus Axelsson,Magnus Axelsson,Uwe Bach,Luca Baldini,Jean Ballet,Guido Barbiellini,Denis Bastieri,B. M. Baughman,Keith Bechtol,Ronaldo Bellazzini,Erika Benítez,Andrei Berdyugin,B. Berenji,Roger Blandford,E. D. Bloom,Markus Boettcher,Emanuele Bonamente,A. W. Borgland,Johan Bregeon,A. Brez,M. Brigida,P. Bruel,T. H. Burnett,David N. Burrows,S. Buson,G. A. Caliandro,L. Calzoletti,R. A. Cameron,M. Capalbi,P. A. Caraveo,D. Carosati,J. M. Casandjian,E. Cavazzuti,C. Cecchi,Omer Celik,Omer Celik,E. Charles,Sylvain Chaty,A. Chekhtman,A. Chekhtman,Wen Ping Chen,James Chiang,G. Chincarini,Stefano Ciprini,R. Claus,Johann Cohen-Tanugi,S. Colafrancesco,L. R. Cominsky,Jan Conrad,Jan Conrad,L. Costamante,S. Cutini,F. D'Ammando,R. Deitrick,V. D'Elia,Charles D. Dermer,A. De Angelis,F. de Palma,Seth Digel,I. Donnarumma,E. Do Couto E Silva,Persis S. Drell,R. Dubois,Deborah Dultzin,D. Dumora,A. D. Falcone,C. Farnier,C. Favuzzi,S. J. Fegan,W. B. Focke,E. Forné,P. Fortin,Marco Frailis,Lars Fuhrmann,Yasushi Fukazawa,Stefan Funk,P. Fusco,José L. Gómez,F. Gargano,Dario Gasparrini,Neil Gehrels,S. Germani,B. Giebels,Nicola Giglietto,Paolo Giommi,F. Giordano,A. Giuliani,T. Glanzman,G. Godfrey,I. A. Grenier,Caryl Gronwall,J. E. Grove,L. Guillemot,L. Guillemot,Sylvain Guiriec,Mark Gurwell,D. Hadasch,Y. Hanabata,Alice K. Harding,M. Hayashida,E. Hays,S. E. Healey,Jochen Heidt,David Hiriart,D. Horan,E. A. Hoversten,R. E. Hughes,Ryosuke Itoh,Miranda Jackson,Miranda Jackson,Gudlaugur Johannesson,A. S. Johnson,W. N. Johnson,Svetlana G. Jorstad,Matthias Kadler,T. Kamae,Hideaki Katagiri,Jun Kataoka,Nobuyuki Kawai,J. A. Kennea,Matthew Kerr,Givi N. Kimeridze,Jürgen Knödlseder,M. L. Kocian,E. N. Kopatskaya,Ekaterina Koptelova,Tatiana S. Konstantinova,Yuri Y. Kovalev,Yu. A. Kovalev,Omar M. Kurtanidze,M. Kuss,J. Lande,Valeri M. Larionov,Luca Latronico,Paolo Leto,Elina Lindfors,Francesco Longo,F. Loparco,Benoit Lott,M. N. Lovellette,P. Lubrano,Grzegorz Madejski,A. Makeev,A. Makeev,P. Marchegiani,Alan P. Marscher,F. E. Marshall,Walter Max-Moerbeck,M. N. Mazziotta,W. McConville,W. McConville,Julie McEnery,Julie McEnery,C. Meurer,Peter F. Michelson,W. Mitthumsiri,Tsunefumi Mizuno,A. A. Moiseev,A. A. Moiseev,C. Monte,M. E. Monzani,A. Morselli,Igor V. Moskalenko,S. Murgia,I. Nestoras,K. Nilsson,N. A. Nizhelsky,P. L. Nolan,J. P. Norris,E. Nuss,T. Ohsugi,Roopesh Ojha,Nicola Omodei,E. Orlando,Jonathan F. Ormes,J. P. Osborne,M. Ozaki,L. Pacciani,Paolo Padovani,C. Pagani,K. L. Page,David Paneque,J. H. Panetta,D. Parent,M. Pasanen,Vasiliki Pavlidou,V. Pelassa,M. Pepe,M. Perri,Melissa Pesce-Rollins,S. Piranomonte,F. Piron,C. Pittori,T. A. Porter,Simonetta Puccetti,Farid Rahoui,S. Rainò,C. M. Raiteri,Robert R. Rando,M. Razzano,A. Reimer,A. Reimer,Olaf Reimer,Olaf Reimer,T. Reposeur,Joseph L. Richards,Steven Ritz,L.S. Rochester,A. Y. Rodriguez,Roger W. Romani,J. A. Ros,M. Roth,P. Roustazadeh,Felix Ryde,Felix Ryde,H. F.W. Sadrozinski,A. C. Sadun,David Sánchez,A. Sander,P. M. Saz Parkinson,Jeffrey D. Scargle,A. Sellerholm,Carmelo Sgrò,M. S. Shaw,Lorand A. Sigua,E. J. Siskind,David A. Smith,P. D. Smith,Gloria Spandre,P. Spinelli,Jean-Luc Starck,Mark Stevenson,G. Stratta,M. S. Strickman,D. J. Suson,H. Tajima,Hiromitsu Takahashi,Tadayuki Takahashi,L. O. Takalo,Takaaki Tanaka,J. B. Thayer,J. G. Thayer,D. J. Thompson,L. Tibaldo,Diego F. Torres,Gino Tosti,A. Tramacere,A. Tramacere,Yasunobu Uchiyama,T. L. Usher,V. Vasileiou,V. Vasileiou,F. Verrecchia,N. Vilchez,M. Villata,V. Vitale,A. P. Waite,Paul J. Wang,Brian L Winer,K. S. Wood,T. Ylinen,T. Ylinen,J. A. Zensus,G. V. Zhekanis,M. Ziegler +273 more
Abstract: We have conducted a detailed investigation of the broadband 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 Swift, radio, infra-red, optical, and other hard X-ray/gamma-ray data, collected within 3 months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous spectral energy distributions (SED) for 48 LBAS blazars. The SED of these gamma-ray sources is similar to that of blazars discovered at other wavelengths, clearly showing, in the usual log nu-log nu F-nu representation, the typical broadband spectral signatures normally attributed to a combination of low-energy synchrotron radiation followed by inverse Compton emission of one or more components. We have used these SED to characterize the peak intensity of both the low-and the high-energy components. The results have been used to derive empirical relationships that estimate the position of the two peaks from the broadband colors (i.e., the radio to optical, alpha(ro), and optical to X-ray, alpha(ox), spectral slopes) and from the gamma-ray spectral index. Our data show that the synchrotron peak frequency (nu(S)(peak)) is positioned between 10(12.5) and 10(14.5) Hz in broad-lined flat spectrum radio quasars (FSRQs) and between 10(13) and 10(17) Hz in featureless BL Lacertae objects. We find that the gamma-ray spectral slope is strongly correlated with the synchrotron peak energy and with the X-ray spectral index, as expected at first order in synchrotron-inverse Compton scenarios. However, simple homogeneous, one-zone, synchrotron self-Compton (SSC) models cannot explain most of our SED, especially in the case of FSRQs and low energy peaked (LBL) BL Lacs. More complex models involving external Compton radiation or multiple SSC components are required to reproduce the overall SED and the observed spectral variability. While more than 50% of known radio bright high energy peaked (HBL) BL Lacs are detected in the LBAS sample, only less than 13% of known bright FSRQs and LBL BL Lacs are included. This suggests that the latter sources, as a class, may be much fainter gamma-ray emitters than LBAS blazars, and could in fact radiate close to the expectations of simple SSC models. We categorized all our sources according to a new physical classification scheme based on the generally accepted paradigm for Active Galactic Nuclei and on the results of this SED study. Since the LAT detector is more sensitive to flat spectrum gamma-ray sources, the correlation between nu(S)(peak) and gamma-ray spectral index strongly favors the detection of high energy peaked blazars, thus explaining the Fermi overabundance of this type of sources compared to radio and EGRET samples. This selection effect is similar to that experienced in the soft X-ray band where HBL BL Lacs are the dominant type of blazars.
Journal ArticleDOI
The association of GRB 060218 with a supernova and the evolution of the shock wave
Sergio Campana,Vanessa Mangano,A. J. Blustin,Peter J. Brown,David N. Burrows,Guido Chincarini,Guido Chincarini,Jay Cummings,Jay Cummings,Giancarlo Cusumano,M. Della Valle,M. Della Valle,D. Malesani,Peter Mészáros,John A. Nousek,M. J. Page,T. Sakamoto,T. Sakamoto,Eli Waxman,Bing Zhang,Z. G. Dai,Z. G. Dai,Neil Gehrels,Stefan Immler,F. E. Marshall,K. O. Mason,Alberto Moretti,P. T. O'Brien,J. P. Osborne,K. L. Page,P. Romano,P. W. A. Roming,Gianpiero Tagliaferri,L. R. Cominsky,Paolo Giommi,Olivier Godet,J. A. Kennea,Hans A. Krimm,Hans A. Krimm,Lorella Angelini,Scott Barthelmy,P. T. Boyd,David Palmer,Alan A. Wells,Nicholas E. White +44 more
TL;DR: A supernova is caught in the act of exploding, directly observing the shock break-out, which indicates that the GRB progenitor was a Wolf–Rayet star.