Browsing by Author "Bonamente, E."

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    The First Pulse of the Extremely Bright GRB 130427A: A Test Lab for Synchrotron Shocks
    (American Association for the Advancement of Science, 2014) Preece, R.; Burgess, J. Michael; von Kienlin, A.; Bhat, P.N.; Briggs, M.S.; Byrne, D.; Chaplin, V.; Cleveland, W.; Collazzi, A.C.; Connaughton, V.; Diekmann, A.; Fitzpatrick, G.; Foley, S.; Gibby, M.; Giles, M.; Goldstein, A.; Greiner, J.; Gruber, D.; Jenke, P.; Kippen, R.M.; Kouveliotou, C.; McBreen, S.; Meegan, C.; Paciesas, W.S.; Pelassa, V.; Tierney, D.; van der Horst, A.J.; Wilson-Hodge, C.; Xiong, S.; Younes, G.; Yu, H.-F.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Baring, M.G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bonamente, E.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G.A.; Cameron, R.A.; Caraveo, P.A.; Cecchi, C.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L.R.; Conrad, J.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C.D.; Desiante, R.; Digel, S.W.; Di Venere, L.; Drell, P.S.; Drlica-Wagner, A.; Favuzzi, C.; Franckowiak, A.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Godfrey, G.; Granot, J.; Grenier, I.A.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A.K.; Hayashida, M.; Iyyani, S.; Jogler, T.; Jóhannesson, G.; Kawano, T.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Lande, J.; Larsson, J.; Larsson, S.; Latronico, L.; Longo, F.; Loparco, F.; Lovellette, M.N.; Lubrano, P.; Mayer, M.; Mazziotta, M.N.; Michelson, P.F.; Mizuno, T.; Monzani, M.E.; Moretti, E.; Morselli, A.; Murgia, S.; Nemmen, R.; Nuss, E.; Nymark, T.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orienti, M.; Paneque, D.; Perkins, J.S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T.A.; Racusin, J.L.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Ritz, S.; Roth, M.; Ryde, F.; Sartori, A.; Scargle, J.D.; Schulz, A.; Sgrò, C.; Siskind, E.J.; Spandre, G.; Spinelli, P.; Suson, D.J.; Tajima, H.; Takahashi, H.; Thayer, J.G.; Thayer, J.B.; Tibaldo, L.; Tinivella, M.; Torres, D.F.; Tosti, G.; Troja, E.; Usher, T.L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Werner, M.; Winer, B.L.; Wood, K.S.; Zhu, S.
    Gamma-ray burst (GRB) 130427A is one of the most energetic GRBs ever observed. The initial pulse up to 2.5 seconds is possibly the brightest well-isolated pulse observed to date. A fine time resolution spectral analysis shows power-law decays of the peak energy from the onset of the pulse, consistent with models of internal synchrotron shock pulses. However, a strongly correlated power-law behavior is observed between the luminosity and the spectral peak energy that is inconsistent with curvature effects arising in the relativistic outflow. It is difficult for any of the existing models to account for all of the observed spectral and temporal behaviors simultaneously.
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    PSR J2021+4026 in the Gamma Cygni Region: The First Variable y-Ray Pulsar Seen by the Fermi Lat
    (The American Astronomical Society, 2013) Baring, M.G.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bonamente, E.; Bottacini, E.; Brandt, T.J.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G.A.; Cameron, R.A.; Caraveo, P.A.; Cecchi, C.; Chaves, R.C.G.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; D'Ammando, F.; de Palma, F.; Digel, S.W.; Di Venere, L.; Drell, P.S.; Favuzzi, C.; Ferrara, E.C.; Franckowiak, A.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I.A.; Guiriec, S.; Hadasch, D.; Harding, A.K.; Hayashida, M.; Hayashi, K.; Hays, E.; Hewitt, J.; Hill, A.B.; Horan, D.; Hou, X.; Jogler, T.; Johnson, A.S.; Johnson, T.J.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Lande, J.; Loparco, F.; Lubrano, P.; Malyshev, D.; Marelli, M.; Mayer, M.; Mazziotta, M.N.; Mehault, J.; Mizuno, T.; Monzani, M.E.; Morselli, A.; Murgia, S.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Paneque, D.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Porter, T.A.; Rainò, S.; Rando, R.; Ray, P.S.; Razzano, M.; Reimer, O.; Reposeur, T.; Romani, R.W.; Sartori, A.; Saz Parkinson, P.M.; Sgrò, C.; Siskind, E.J.; Smith, D.A.; Spinelli, P.; Strong, A.W.; Takahashi, H.; Thayer, J.B.; Thompson, D.J.; Tibaldo, L.; Tinivella, M.; Torres, D.F.; Tosti, G.; Uchiyama, Y.; Usher, T.L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Winer, B.L.; Wood, K.S.
    Long-term monitoring of PSR J2021+4026 in the heart of the Cygnus region with the Fermi Large Area Telescope unveiled a sudden decrease in flux above 100 MeV over a timescale shorter than a week. The "jump" was near MJD 55850 (2011 October 16), with the flux decreasing from (8.33 ± 0.08) × 10–10 erg cm–2 s–1 to (6.86 ± 0.13) × 10–10 erg cm–2 s–1. Simultaneously, the frequency spindown rate increased from (7.8 ± 0.1) × 10–13 Hz s–1 to (8.1 ± 0.1) × 10–13 Hz s–1. Significant (>5σ) changes in the pulse profile and marginal (<3σ) changes in the emission spectrum occurred at the same time. There is also evidence for a small, steady flux increase over the 3 yr preceding MJD 55850. This is the first observation at γ-ray energies of mode changes and intermittent behavior, observed at radio wavelengths for other pulsars. We argue that the change in pulsed γ-ray emission is due to a change in emission beaming and we speculate that it is precipitated by a shift in the magnetic field structure, leading to a change of either effective magnetic inclination or effective current.
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    The Second Fermi Large Area Telescope Catalog of Gamma-Ray Pulsars
    (The American Astronomical Society, 2013-10) Baring, M.G.; Abdo, A.A.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bhattacharyya, B.; Bissaldi, E.; Bloom, E.D.; Bonamente, E.; Bottacini, E.; Brandt, T.J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burgay, M.; Burnett, T.H.; Busetto, G.; Buson, S.; Cameron, R.A.; Camilo, F.; Caraveo, P.A.; Casandjian, J.M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chaves, R.C.G.; Chekhtman, A.; Chen, A.W.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cognard, I.; Cohen-Tanugi, J.; Cominsky, L.R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; DeCesar, M.E.; De Luca, A.; den Hartog, P.R.; de Palma, F.; Dermer, C.D.; Desvignes, G.; Digel, S.W.; Di Venere, L.; Drell, P.S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Espinoza, C.M.; Falletti, L.; Favuzzi, C.; Ferrara, E.C.; Focke, W.B.; Franckowiak, A.; Freire, P.C.C.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gotthelf, E.V.; Grenier, I.A.; Grondin, M.-H.; Grove, J.E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Harding, A.K.; Hayashida, M.; Hays, E.; Hessels, J.; Hewitt, J.; Hill, A.B.; Horan, D.; Hou, X.; Hughes, R.E.; Jackson, M.S.; Janssen, G.H.; Jogler, T.; Jóhannesson, G.; Johnson, R.P.; Johnson, A.S.; Johnson, T.J.; Johnson, W.N.; Johnston, S.; Kamae, T.; Kataoka, J.; Keith, M.; Kerr, M.; Knӧdlseder, J.; Kramer, M.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lovellette, M.N.; Lubrano, P.; Lyne, A.G.; Manchester, R.N.; Marelli, M.; Massaro, F.; Mayer, M.; Mazziotta, M.N.; McEnery, J.E.; McLaughlin, M.A.; Mehault, J.; Michelson, P.F.; Mignani, R.P.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A.A.; Monzani, M.E.; Morselli, A.; Moskalenko, I.V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohno, M.; Ohsugi, T.; Orienti, M.; Orlando, E.; Ormes, J.F.; Paneque, D.; Panetta, J.H.; Parent, D.; Perkins, J.S.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Pletsch, H.J.; Porter, T.A.; Possenti, A.; Rainò, S.; Rando, R.; Ransom, S.M.; Ray, P.S.; Razzano, M.; Rea, N.; Reimer, A.; Reimer, O.; Renault, N.; Reposeur, T.; Ritz, S.; Romani, R.W.; Roth, M.; Rousseau, R.; Roy, J.; Ruan, J.; Sartori, A.; Saz Parkinson, P.M.; Scargle, J.D.; Schulz, A.; Sgrò, C.; Shannon, R.; Siskind, E.J.; Smith, D.A.; Spandre, G.; Spinelli, P.; Stappers, B.W.; Strong, A.W.; Suson, D.J.; Takahashi, H.; Thayer, J.G.; Thayer, J.B.; Theureau, G.; Thompson, D.J.; Thorsett, S.E.; Tibaldo, L.; Tibolla, O.; Tinivella, M.; Torres, D.F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T.L.; Vandenbroucke, J.; Vasileiou, V.; Venter, C.; Vianello, G.; Vitale, V.; Wang, N.; Weltevrede, P.; Winer, B.L.; Wolff, M.T.; Wood, D.L.; Wood, K.S.; Wood, M.; Yang, Z.
    This catalog summarizes 117 high-confidence 0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars.We compare the gammaray properties with those in the radio, optical, and X-ray bands.We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermiﾒs selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.