ALBERT

Description: 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉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 -- Johannesson, G -- Kawano, T -- Knodlseder, 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 -- Raino, S -- Rando, R -- Razzano, M -- Razzaque, S -- Reimer, A -- Reimer, O -- Ritz, S -- Roth, M -- Ryde, F -- Sartori, A -- Scargle, J D -- Schulz, A -- Sgro, 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 -- New York, N.Y. -- Science. 2014 Jan 3;343(6166):51-4. doi: 10.1126/science.1242302. Epub 2013 Nov 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24263132" target="_blank"〉PubMed〈/a〉

Description: The observations of the exceptionally bright gamma-ray burst (GRB) 130427A by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope provide constraints on the nature of these unique astrophysical sources. GRB 130427A had the largest fluence, highest-energy photon (95 GeV), longest gamma-ray duration (20 hours), and one of the largest isotropic energy releases ever observed from a GRB. Temporal and spectral analyses of GRB 130427A challenge the widely accepted model that the nonthermal high-energy emission in the afterglow phase of GRBs is synchrotron emission radiated by electrons accelerated at an external shock.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ackermann, M -- Ajello, M -- Asano, K -- Atwood, W B -- Axelsson, M -- Baldini, L -- Ballet, J -- Barbiellini, G -- Baring, M G -- Bastieri, D -- Bechtol, K -- Bellazzini, R -- Bissaldi, E -- Bonamente, E -- Bregeon, J -- Brigida, M -- Bruel, P -- Buehler, R -- Burgess, J Michael -- Buson, S -- Caliandro, G A -- Cameron, R A -- Caraveo, P A -- Cecchi, C -- Chaplin, V -- Charles, E -- Chekhtman, A -- Cheung, C C -- Chiang, J -- Chiaro, G -- Ciprini, S -- Claus, R -- Cleveland, W -- Cohen-Tanugi, J -- Collazzi, A -- Cominsky, L R -- Connaughton, V -- Conrad, J -- Cutini, S -- D'Ammando, F -- de Angelis, A -- DeKlotz, M -- de Palma, F -- Dermer, C D -- Desiante, R -- Diekmann, A -- Di Venere, L -- Drell, P S -- Drlica-Wagner, A -- Favuzzi, C -- Fegan, S J -- Ferrara, E C -- Finke, J -- Fitzpatrick, G -- Focke, W B -- Franckowiak, A -- Fukazawa, Y -- Funk, S -- Fusco, P -- Gargano, F -- Gehrels, N -- Germani, S -- Gibby, M -- Giglietto, N -- Giles, M -- Giordano, F -- Giroletti, M -- Godfrey, G -- Granot, J -- Grenier, I A -- Grove, J E -- Gruber, D -- Guiriec, S -- Hadasch, D -- Hanabata, Y -- Harding, A K -- Hayashida, M -- Hays, E -- Horan, D -- Hughes, R E -- Inoue, Y -- Jogler, T -- Johannesson, G -- Johnson, W N -- Kawano, T -- Knodlseder, J -- Kocevski, D -- Kuss, M -- Lande, J -- Larsson, S -- Latronico, L -- Longo, F -- Loparco, F -- Lovellette, M N -- Lubrano, P -- Mayer, M -- Mazziotta, M N -- McEnery, J E -- Michelson, P F -- Mizuno, T -- Moiseev, A A -- Monzani, M E -- Moretti, E -- Morselli, A -- Moskalenko, I V -- Murgia, S -- Nemmen, R -- Nuss, E -- Ohno, M -- Ohsugi, T -- Okumura, A -- Omodei, N -- Orienti, M -- Paneque, D -- Pelassa, V -- Perkins, J S -- Pesce-Rollins, M -- Petrosian, V -- Piron, F -- Pivato, G -- Porter, T A -- Racusin, J L -- Raino, S -- Rando, R -- Razzano, M -- Razzaque, S -- Reimer, A -- Reimer, O -- Ritz, S -- Roth, M -- Ryde, F -- Sartori, A -- Parkinson, P M Saz -- Scargle, J D -- Schulz, A -- Sgro, C -- Siskind, E J -- Sonbas, E -- Spandre, G -- Spinelli, P -- Tajima, H -- Takahashi, H -- Thayer, J G -- Thayer, J B -- Thompson, D J -- Tibaldo, L -- Tinivella, M -- Torres, D F -- Tosti, G -- Troja, E -- Usher, T L -- Vandenbroucke, J -- Vasileiou, V -- Vianello, G -- Vitale, V -- Winer, B L -- Wood, K S -- Yamazaki, R -- Younes, G -- Yu, H-F -- Zhu, S J -- Bhat, P N -- Briggs, M S -- Byrne, D -- Foley, S -- Goldstein, A -- Jenke, P -- Kippen, R M -- Kouveliotou, C -- McBreen, S -- Meegan, C -- Paciesas, W S -- Preece, R -- Rau, A -- Tierney, D -- van der Horst, A J -- von Kienlin, A -- Wilson-Hodge, C -- Xiong, S -- Cusumano, G -- La Parola, V -- Cummings, J R -- New York, N.Y. -- Science. 2014 Jan 3;343(6166):42-7. doi: 10.1126/science.1242353. Epub 2013 Nov 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24263133" target="_blank"〉PubMed〈/a〉

Description: Asteroseismology, i.e. the study of the internal structures of stars via their global oscillations, is a valuable tool to obtain stellar parameters such as mass, radius, surface gravity and mean density. These parameters can be obtained using certain scaling relations which are based on an asymptotic approximation. Usually the observed oscillation parameters are assumed to follow these scaling relations. Recently, it has been questioned whether this is a valid approach, i.e. whether the order of the observed oscillation modes is high enough to be approximated with an asymptotic theory. In this work, we use stellar models to investigate whether the differences between observable oscillation parameters and their asymptotic estimates are indeed significant. We compute the asymptotic values directly from the stellar models and derive the observable values from adiabatic pulsation calculations of the same models. We find that the extent to which the atmosphere is included in the models is a key parameter. Considering a larger extension of the atmosphere beyond the photosphere reduces the difference between the asymptotic and observable values of the large frequency separation. Therefore, we conclude that the currently suggested discrepancies in the scaling relations might have been overestimated. Hence, based on the results presented here we believe that the suggestions of Mosser et al. should not be followed without careful consideration.

Description: Gamma-ray burst (GRB) 130427A is one of the most energetic GRBs ever observed. The initial pulse up to 2.5 s 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.

Description: In the first two years of science operations of the Fermi Gamma-ray Burst Monitor (GBM), August 2008 to August 2010, approximately 7% (70 mcrab) decline was discovered in the overall Crab Nebula flux in the 15 - 50 keV band, measured with the Earth occultation technique. This decline was independently confirmed with four other instruments: the RXTE/PCA, Swift/BAT, INTEGRAL/IBIS, and INTEGRAL/SPI. The pulsed flux measured with RXTE/PCA from 1999-2010 was consistent with the pulsar spin-down, indicating that the observed changes were nebular. From 2001 to 2010, the Crab nebula flux measured with RXTE/PCA was particularly variable, changing by up to approximately 3.5% per year in the 15-50 keV band. These variations were confirmed with INTEGRAL/SPI starting in 2003, Swift/BAT starting in 2005, and Fermi GBM starting in 2008. Before 2001 and since 2010, the Crab nebula flux has appeared more stable, varying by less than 2% per year. I will present updated light curves in multiple energy bands for the Crab nebula, including recent data from Fermi GBM, Swift/BAT, INTEGRAL and MAXI, and a 16-year long light curve from RXTE/PCA.