Browsing by Author "Racusin, J.L."

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    Fermi-LAT Observations of LIGO/Virgo Event GW170817
    (IOP Publishing, 2018) Ajello, M.; Allafort, A.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Baring, M.G.; Bastieri, D.; Bellazzini, R.; Berenji, B.; Bissaldi, E.; Blandford, R.D.; Bloom, E.D.; Bonino, R.; Bottacini, E.; Brandt, T.J.; Bregeon, J.; Bruel, P.; Buehler, R.; Burnett, T.H.; Buson, S.; Cameron, R.A.; Caputo, R.; Caraveo, P.A.; Casandjian, J.M.; Cavazzuti, E.; Chekhtman, A.; Cheung, C.C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cominsky, L.R.; Costantin, D.; Cuoco, A.; Cutini, S.; D’Ammando, F.; de Palma, F.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Dubois, R.; Dumora, D.; Favuzzi, C.; Ferrara, E.C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Gill, R.; Giordano, F.; Giroletti, M.; Glanzman, T.; Granot, J.; Green, D.; Grenier, I.A.; Grondin, M.-H.; Guillemot, L.; Guiriec, S.; Harding, A.K.; Hays, E.; Horan, D.; Imazato, F.; Jóhannesson, G.; Kamae, T.; Kensei, S.; Kocevski, D.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Li, J.; Longo, F.; Loparco, F.; Lovellette, M.N.; Lubrano, P.; Magill, J.D.; Maldera, S.; Manfreda, A.; Mazziotta, M.N.; Michelson, P.F.; Mizuno, T.; Moiseev, A.A.; Monzani, M.E.; Moretti, E.; Morselli, A.; Moskalenko, I.V.; Negro, M.; Nuss, E.; Ojha, R.; Omodei, N.; Orlando, E.; Ormes, J.F.; Palatiello, M.; Paliya, V.S.; Paneque, D.; Persic, M.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Porter, T.A.; Principe, G.; Racusin, J.L.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Ritz, S.; Rochester, L.S.; Ryde, F.; Parkinson, P.M. Saz; Sgrò, C.; Siskind, E.J.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D.J.; Tajima, H.; Takahashi, M.; Tak, D.; Thayer, J.G.; Thayer, J.B.; Torres, D.F.; Torresi, E.; Tosti, G.; Troja, E.; Valverde, J.; Venters, T.M.; Vianello, G.; Wood, K.; Yang, C.; Zaharijas, G.
    We present the Fermi Large Area Telescope (LAT) observations of the binary neutron star merger event GW170817 and the associated short gamma-ray burst (SGRB) GRB 170817A detected by the Fermi Gamma-ray Burst Monitor. The LAT was entering the South Atlantic Anomaly at the time of the LIGO/Virgo trigger (t GW) and therefore cannot place constraints on the existence of high-energy (E > 100 MeV) emission associated with the moment of binary coalescence. We focus instead on constraining high-energy emission on longer timescales. No candidate electromagnetic counterpart was detected by the LAT on timescales of minutes, hours, or days after the LIGO/Virgo detection. The resulting flux upper bound (at 95% C.L.) from the LAT is 4.5 × 10−10 erg cm−2 s−1 in the 0.1–1 GeV range covering a period from t GW + 1153 s to t GW + 2027 s. At the distance of GRB 170817A, this flux upper bound corresponds to a luminosity upper bound of 9.7 × 1043 erg s−1, which is five orders of magnitude less luminous than the only other LAT SGRB with known redshift, GRB 090510. We also discuss the prospects for LAT detection of electromagnetic counterparts to future gravitational-wave events from Advanced LIGO/Virgo in the context of GW170817/GRB 170817A.
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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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    GRB110721A: An Extreme Peak Energy and Signatures of the Photosphere
    (The American Astronomical Society, 2012) Baring, M.G.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Bellazzini, R.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Caliandro, G.A.; Cameron, R.A.; Caraveo, P.A.; Cecchi, C.; Chaves, R.C.G.; Chekhtman, A.; Chiang, J.; Claus, R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Palma, F.; Dermer, C.D.; do Couto e Silva, E.; Drell, P.S.; Favuzzi, C.; Fegan, S.J.; Ferrara, E.C.; Focke, W.B.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giroletti, M.; Godfrey, G.; Guiriec, S.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Hou, X.; Iyyani, S.; Jackson, M.S.; Kocevski, D.; Kuss, M.; Larsson, J.; Longo, F.; Loparco, F.; Lundman, C.; Mazziotta, M.N.; McEnery, J.E.; Mizuno, T.; Monzani, M.E.; Moretti, E.; Morselli, A.; Murgia, S.; Nuss, E.; Nymark, T.; Ohno, M.; Omodei, N.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Racusin, J.L.; Rainò, S.; Razzano, M.; Razzaque, S.; Reimer, A.; Roth, M.; Ryde, F.; Sanchez, D.A.; Sgrò, C.; Siskind, E.J.; Spandre, G.; Spinelli, P.; Stamatikos, M.; Tibaldo, L.; Tinivella, M.; Usher, T.L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A.P.; Winer, B.L.; Wood, K.S.; Burgess, J.M.; Bhat, P.N.; Bissaldi, E.; Briggs, M.S.; Connaughton, V.; Fishman, G.; Fitzpatrick, G.; Foley, S.; Gruber, D.; Kippen, R.M.; Kouveliotou, C.; Jenke, P.; McBreen, S.; McGlynn, S.; Meegan, C.; Paciesas, W.S.; Pelassa, V.; Preece, R.; Tierney, D.; von Kienlin, A.; Wilson-Hodge, C.; Xiong, S.; Pe'er, A.; Pe'er, A.
    GRB110721A was observed by the Fermi Gamma-ray Space Telescope using its two instruments, the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). The burst consisted of one major emission episode which lasted for ~24.5 s (in the GBM) and had a peak flux of (5.7 ± 0.2) × 10–5 erg s–1 cm–2. The time-resolved emission spectrum is best modeled with a combination of a Band function and a blackbody spectrum. The peak energy of the Band component was initially 15 ± 2 MeV, which is the highest value ever detected in a GRB. This measurement was made possible by combining GBM/BGO data with LAT Low Energy events to achieve continuous 10-100 MeV coverage. The peak energy later decreased as a power law in time with an index of –1.89 ± 0.10. The temperature of the blackbody component also decreased, starting from ~80 keV, and the decay showed a significant break after ~2 s. The spectrum provides strong constraints on the standard synchrotron model, indicating that alternative mechanisms may give rise to the emission at these energies.
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    Searching the Gamma-Ray Sky for Counterparts to Gravitational Wave Sources: Fermi Gamma-Ray Burst Monitor and Large Area Telescope Observations of LVT151012 and GW151226
    (IOP, 2017) Racusin, J.L.; Burns, E.; Goldstein, A.; Connaughton, V.; Wilson-Hodge, C.A.; Jenke, P.; Blackburn, L.; Briggs, M.S.; Broida, J.; Camp, J.; Christensen, N.; Hui, C.M.; Littenberg, T.; Shawhan, P.; Singer, L.; Veitch, J.; Bhat, P.N.; Cleveland, W.; Fitzpatrick, G.; Gibby, M.H.; von Kienlin, A.; McBreen, S.; Mailyan, B.; Meegan, C.A.; Paciesas, W.S.; Preece, R.D.; Roberts, O.J.; Stanbro, M.; Veres, P.; Zhang, B.-B.; Fermi LAT Collaboration; Ackermann, M.; Albert, A.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M.G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R.D.; Bloom, E.D.; Bonino, R.; Bregeon, J.; Bruel, P.; Buson, S.; Caliandro, G.A.; Cameron, R.A.; Caputo, R.; Caragiulo, M.; Caraveo, P.A.; Cavazzuti, E.; Charles, E.; Chiang, J.; Ciprini, S.; Costanza, F.; Cuoco, A.; Cutini, S.; D'Ammando, F.; de Palma, F.; Desiante, R.; Digel, S.W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Drell, P.S.; Favuzzi, C.; Ferrara, E.C.; Focke, W.B.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Gill, R.; Giroletti, M.; Glanzman, T.; Granot, J.; Green, D.; Grove, J.E.; Guillemot, L.; Guiriec, S.; Harding, A.K.; Jogler, T.; Jóhannesson, G.; Kamae, T.; Kensei, S.; Kocevski, D.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Longo, F.; Loparco, F.; Lubrano, P.; Magill, J.D.; Maldera, S.; Malyshev, D.; Mazziotta, M.N.; McEnery, J.E.; Michelson, P.F.; Mizuno, T.; Monzani, M.E.; Morselli, A.; Moskalenko, I.V.; Negro, M.; Nuss, E.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J.F.; Paneque, D.; Perkins, J.S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T.A.; Principe, G.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Saz Parkinson, P.M.; Scargle, J.D.; Sgrò, C.; Simone, D.; Siskind, E.J.; Smith, D.A.; Spada, F.; Spinelli, P.; Suson, D.J.; Tajima, H.; Thayer, J.B.; Torres, D.F.; Troja, E.; Uchiyama, Y.; Vianello, G.; Wood, K.S.; Wood, M.
    We present the Fermi Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) observations of the LIGO binary black hole merger event GW151226 and candidate LVT151012. At the time of the LIGO triggers on LVT151012 and GW151226, GBM was observing 68% and 83% of the localization regions, and LAT was observing 47% and 32%, respectively. No candidate electromagnetic counterparts were detected by either the GBM or LAT. We present a detailed analysis of the GBM and LAT data over a range of timescales from seconds to years, using automated pipelines and new techniques for characterizing the flux upper bounds across large areas of the sky. Due to the partial GBM and LAT coverage of the large LIGO localization regions at the trigger times for both events, differences in source distances and masses, as well as the uncertain degree to which emission from these sources could be beamed, these non-detections cannot be used to constrain the variety of theoretical models recently applied to explain the candidate GBM counterpart to GW150914.