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On the privacy-conscientious use of mobile phone data

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Scientific data 2018年第1期5卷 180286页

作者： Yves-Alexandre de Montjoye Sébastien Gambs Vincent Blondel Geoffrey Canright Nicolas de Cordes Sébastien Deletaille Kenth Engø-Monsen Manuel Garcia-Herranz Jake Kendall Cameron Kerry Gautier Krings Emmanuel Letouzé Miguel Luengo-Oroz Nuria Oliver Luc Rocher Alex Rutherford Zbigniew Smoreda Jessica Steele Erik Wetter Alex Sandy Pentland Linus Bengtsson Department of Computing Imperial College London London SW7 2AZ UK. MIT Media Lab 20 Ames St Cambridge MA 02139 USA. Université du Québec à Montréal Département d'informatique Case postale 8888 succ. Centre-ville Montréal (Québec) H3C 3P8 Canada. Université catholique de Louvain Place de l'Université 1 1348 Louvain-la-Neuve Belgium. Telenor Research Snarøyveien 30 1360 Fornebu Norway. Orange 44 avenue de la République 92320 Châtillon France. Riaktr 5 Place du Champs de Mars 1050 Brussels Belgium. UNICEF Office of Innovation 3 UN Plaza New York NY 10017 USA. University of Washington Dept. of Computer Science 708b 11th Avenue East Seattle WA 98102 USA. Data-Pop Alliance 99 Madison Avenue 15th Floor New York NY 10016 USA. UN Global Pulse 370 Lexington Avenue New York NY 10017 USA. Vodafone Research Paddington Central London W2 6BY UK. University of Southampton Geography and Environment Building 44 University Road Southampton SO17 1BJ UK. Flowminder Foundation Roslagsgatan 17 SE-11355 Stockholm Sweden. Stockholm School of Economics Sveavägen 65 113 83 Stockholm Sweden. Asian Institute of Management 123 Paseo de Roxas 1229 Metro Manila Philippines.

Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope data

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Physical Review Letters 2017年第9期118卷 091103-091103页

作者： S. Abdollahi M. Ackermann M. Ajello A. Albert W. B. Atwood L. Baldini G. Barbiellini R. Bellazzini E. Bissaldi E. D. Bloom R. Bonino E. Bottacini T. J. Brandt P. Bruel S. Buson M. Caragiulo E. Cavazzuti A. Chekhtman S. Ciprini F. Costanza A. Cuoco S. Cutini F. D’Ammando F. de Palma R. Desiante S. W. Digel N. Di Lalla M. Di Mauro L. Di Venere B. Donaggio P. S. Drell C. Favuzzi W. B. Focke Y. Fukazawa S. Funk P. Fusco F. Gargano D. Gasparrini N. Giglietto F. Giordano M. Giroletti D. Green S. Guiriec A. K. Harding T. Jogler G. Jóhannesson T. Kamae M. Kuss S. Larsson L. Latronico J. Li F. Longo F. Loparco P. Lubrano J. D. Magill D. Malyshev A. Manfreda M. N. Mazziotta M. Meehan P. F. Michelson W. Mitthumsiri T. Mizuno A. A. Moiseev M. E. Monzani A. Morselli M. Negro E. Nuss T. Ohsugi N. Omodei D. Paneque J. S. Perkins M. Pesce-Rollins F. Piron G. Pivato G. Principe S. Rainò R. Rando M. Razzano A. Reimer O. Reimer C. Sgrò D. Simone E. J. Siskind F. Spada G. Spandre P. Spinelli A. W. Strong H. Tajima J. B. Thayer D. F. Torres E. Troja J. Vandenbroucke G. Zaharijas S. Zimmer Department of Physical Sciences Hiroshima University Higashi-Hiroshima Hiroshima 739-8526 Japan Deutsches Elektronen Synchrotron DESY D-15738 Zeuthen Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics Clemson South Carolina 29634-0978 USA Los Alamos National Laboratory Los Alamos New Mexico 87545 USA Santa Cruz Institute for Particle Physics Department of Physics and Department of Astronomy and Astrophysics University of California at Santa Cruz Santa Cruz California 95064 USA Dipartimento di Fisica “Enrico Fermi” dell’Università di Pisa I-56126 Pisa Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa I-56127 Pisa Italy Istituto Nazionale di Fisica Nucleare Sezione di Trieste I-34127 Trieste Italy Dipartimento di Fisica Università di Trieste I-34127 Trieste Italy Dipartimento di Fisica “M. Merlin” dell’Università e del Politecnico di Bari I-70126 Bari Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari I-70126 Bari Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics and SLAC National Accelerator Laboratory Stanford University Stanford California 94305 USA Istituto Nazionale di Fisica Nucleare Sezione di Torino I-10125 Torino Italy Dipartimento di Fisica Università degli Studi di Torino I-10125 Torino Italy NASA Goddard Space Flight Center Greenbelt Maryland 20771 USA Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 F-91128 Palaiseau France Agenzia Spaziale Italiana (ASI) Science Data Center I-00133 Roma Italy College of Science George Mason University Fairfax Virginia 22030 USA resident at Naval Research Laboratory Washington DC 20375 USA Istituto Nazionale di Fisica Nucleare Sezione di Perugia I-06123 Perugia Italy Institute for Theoretical Particle Physics and Cosmology (TTK) RWTH Aachen University D-52056 Aachen Germany INAF Istituto di Radioastronomia I-40129 Bologna Italy Dipartimento di Astronomia Un

The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10−3. We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. The present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

关键词： Cosmic ray & astroparticle detectors Cosmic ray propagation Cosmic ray sources Cosmological parameters

Multi-Swarm bat algorithm

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Research Journal of Applied sciences, Engineering and Technology 2015年第12期10卷 1389-1395页

作者： Taha, Ahmed Majid Chen, Soong-Der Mustapha, Aida Soft Computing and Data Mining Center Universiti Tun Hussein Onn Malaysia Parit Raja Batu Pahat Johor 86400 Malaysia College of Information Technology Universiti Tenaga Nasional Kajang Selangor 43000 Malaysia Faculty of Computer Science and Information Technology Universiti Tun Hussein Onn Malaysia Parit Raja Batu Pahat 86400 Malaysia

In this study a new Bat Algorithm (BA) based on multi-swarm technique called the Multi-Swarm Bat Algorithm (MSBA) is proposed to address the problem of premature convergence phenomenon. The problem happens when search process converges to non-optimal solution due to the loss of diversity during the evolution process. MSBA was designed with improved ability in exploring new solutions, which was essential in reducing premature convergence. The exploration ability was improved by having a number of sub-swarms watching over the best local optima. In MSBA, when the quality of best local optima does not improve after a pre-defined number of iterations, the population is split equally into several smaller sub-swarms, with one of them remains close to the current best local optima for further exploitation while the other sub-swarms continue to explore for new local optima. The proposed algorithm has been applied in feature selection problem and the results were compared against eight algorithms, which are Ant Colony Optimization (ACO), Genetic Algorithm (GA), Tabu Search (TS), Scatter Search (SS), Great Deluge Algorithm (GDA) and stander BA. The results showed that the MSBA is much more effective that it is able to find new best solutions at times when the rest of other algorithms are not able to. © Maxwell Scientific Organization, 2015.

关键词： Bat algorithm Bio-inspired algorithms data mining Feature selection Multi-swarm Optimization

Unresolved gamma-ray sky through its angular power spectrum

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arXiv 2018年

作者： Ackermann, M. Ajello, M. Baldini, L. Ballet, J. Barbiellini, G. Bastieri, D. Bellazzini, R. Bissaldi, E. Blandford, R.D. Bonino, R. Bottacini, E. Bregeon, J. Bruel, P. Buehler, R. Burns, E. Buson, S. Cameron, R.A. Caputo, R. Caraveo, P.A. Cavazzuti, E. Chen, S. Chiaro, G. Ciprini, S. Costantin, D. Cuoco, A. Cutini, S. D’Ammando, F. de la Torre Luque, P. de Palma, F. Desai, A. Digel, S.W. Di Lalla, N. Di Mauro, M. Di Venere, L. Fana Dirirsa, F. Favuzzi, C. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giordano, F. Giroletti, M. Green, D. Grenier, I.A. Guillemot, L. Guiriec, S. Horan, D. Jóhannesson, G. Kuss, M. Larsson, S. Latronico, L. Li, J. Liodakis, I. Longo, F. Loparco, F. Lubrano, P. Magill, J.D. Maldera, S. Malyshev, D. Manfreda, A. Mazziotta, M.N. Mereu, I. Michelson, P.F. Mitthumsiri, W. Mizuno, T. Monzani, M.E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Orienti, M. Orlando, E. Palatiello, M. Paliya, V.S. Paneque, D. Persic, M. Pesce-Rollins, M. Petrosian, V. Piron, F. Porter, T.A. Principe, G. Rainò, S. Rando, R. Razzano, M. Razzaque, S. Reimer, A. Reimer, O. Serini, D. Sgrò, C. Siskind, E.J. Spandre, G. Spinelli, P. Suson, D.J. Tajima, H. Takahashi, M. Thayer, J.B. Tibaldo, L. Torres, D.F. Troja, E. Venters, T.M. Vianello, G. Wood, K. Yassine, M. Zaharijas, G. Ammazzalorso, S. Fornengo, N. Regis, M. Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Università di Pisa Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Laboratoire AIM CEA-IRFU CNRS Université Paris Diderot Service d’Astrophysique CEA Saclay Gif sur YvetteF-91191 France Istituto Nazionale di Fisica Nucleare Sezione di Trieste TriesteI-34127 Italy Dipartimento di Fisica Università di Trieste TriesteI-34127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy Dipartimento di Fisica e Astronomia "G. Galilei" Università di Padova PadovaI-35131 Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Dipartimento di Fisica "M. Merlin" dell’Università e del Politecnico di Bari BariI-70126 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari BariI-70126 Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics SLAC National Accelerator Laboratory Stanford University StanfordCA94305 United States Istituto Nazionale di Fisica Nucleare Sezione di Torino TorinoI-10125 Italy Dipartimento di Fisica Università degli Studi di Torino TorinoI-10125 Italy Department of Physics and Astronomy University of Padova Vicolo Osservatorio 3 PadovaI-35122 Italy Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 MontpellierF-34095 France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France NASA Goddard Space Flight Center GreenbeltMD20771 United States NASA Postdoctoral Program Fellow United States NASA Goddard Space Flight Center GreenbeltMD20771 United States INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Milano via E. Bassini 15 MilanoI-20133 Italy Italian Space Agency Via del Politecnico snc Roma00133 Italy Space Science Data Center -

The gamma-ray sky has been observed with unprecedented accuracy in the last decade by the Fermi large area telescope (LAT), allowing us to resolve and understand the high-energy Universe. The nature of the remaining unresolved emission (unresolved gamma-ray background, UGRB) below the LAT source detection threshold can be uncovered by characterizing the amplitude and angular scale of the UGRB fluctuation field. This work presents a measurement of the UGRB autocorrelation angular power spectrum based on eight years of Fermi LAT Pass 8 data products. The analysis is designed to be robust against contamination from resolved sources and noise systematics. The sensitivity to subthreshold sources is greatly enhanced with respect to previous measurements. We find evidence (with ∼ 3.7σ significance) that the scenario in which two classes of sources contribute to the UGRB signal is favored over a single class. A double power law with exponential cutoff can explain the anisotropy energy spectrum well, with photon indices of the two populations being 2.55 ± 0.23 and 1.86 ± 0.15. Copyright © 2018, The Authors. All rights reserved.

关键词： Gamma rays

Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope data

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arXiv 2017年

作者： Abdollahi, S. Ackermann, M. Ajello, M. Albert, A. Atwood, W.B. Baldini, L. Barbiellini, G. Bellazzini, R. Bissaldi, E. Bloom, E.D. Bonino, R. Bottacini, E. Brandt, T.J. Bruel, P. Buson, S. Caragiulo, M. Cavazzuti, E. Chekhtman, A. 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. Donaggio, B. Drell, P.S. Favuzzi, C. Focke, W.B. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giordano, F. Giroletti, M. Green, D. Guiriec, S. Harding, A.K. Jogler, T. Jóhannesson, G. Kamae, T. Kuss, M. Larsson, S. Latronico, L. Li, J. Longo, F. Loparco, F. Lubrano, P. Magill, J.D. Malyshev, D. Manfreda, A. Mazziotta, M.N. Meehan, M. Michelson, P.F. Mitthumsiri, W. Mizuno, T. Moiseev, A.A. Monzani, M.E. Morselli, A. Negro, M. Nuss, E. Ohsugi, T. Omodei, N. Paneque, D. Perkins, J.S. Pesce-Rollins, M. Piron, F. Pivato, G. Principe, G. Rainò, S. Rando, R. Razzano, M. Reimer, A. Reimer, O. Sgrò, C. Simone, D. Siskind, E.J. Spada, F. Spandre, G. Spinelli, P. Strong, A.W. Tajima, H. Thayer, J.B. Torres, D.F. Troja, E. Vandenbroucke, J. Zaharijas, G. Zimmer, S. Department of Physical Sciences Hiroshima University Higashi-HiroshimaHiroshima739-8526 Japan Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Los Alamos National Laboratory Los AlamosNM87545 United States Santa Cruz Institute for Particle Physics Department of Physics Department of Astronomy and Astrophysics University of California at Santa Cruz Santa CruzCA95064 United States Dipartimento di Fisica "Enrico Fermi" dell’Università di Pisa PisaI-56126 Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Trieste TriesteI-34127 Italy Dipartimento di Fisica Università di Trieste TriesteI-34127 Italy Dipartimento di Fisica "M. Merlin" dell’Università e del Politecnico di Bari BariI-70126 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari BariI-70126 Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics SLAC National Accelerator Laboratory Stanford University StanfordCA94305 United States Istituto Nazionale di Fisica Nucleare Sezione di Torino TorinoI-10125 Italy Dipartimento di Fisica Università degli Studi di Torino TorinoI-10125 Italy NASA Goddard Space Flight Center GreenbeltMD20771 United States Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France Science Data Center RomaI-00133 Italy College of Science George Mason University FairfaxVA22030 United States Istituto Nazionale di Fisica Nucleare Sezione di Perugia PerugiaI-06123 Italy RWTH Aachen University AachenD-52056 Germany INAF Istituto di Radioastronomia BolognaI-40129 Italy Dipartimento di Astronomia Università di Bologna BolognaI-40127 Italy Università Telematica Pegaso Piazza Trieste e Trento 48 NapoliI-80132 Italy Università di Udine UdineI-33100

Search for spatial extension in high-latitude sources detected by the fermi large area telescope

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arXiv 2018年

作者： Ackermann, M. Ajello, M. Baldini, L. Ballet, J. Barbiellini, G. Bastieri, D. Bellazzini, R. Bissaldi, E. Blandford, R.D. Bloom, E.D. Bonino, R. Bottacini, E. Brandt, T.J. Bregeon, J. Bruel, P. Buehler, R. Cameron, R.A. Caputo, R. Caraveo, P.A. Castro, D. Cavazzuti, E. Charles, E. Cheung, C.C. Chiaro, G. Ciprini, S. Cohen-Tanugi, J. Costantin, D. Cutini, S. D'Ammando, F. de Palma, F. Desai, A. Di Lalla, N. Di Mauro, M. Di Venere, L. Favuzzi, C. Finke, J. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giordano, F. Giroletti, M. Green, D. Grenier, I.A. Guillemot, L. Guiriec, S. Hays, E. Hewitt, J.W. Horan, D. Jóhannesson, G. Kensei, S. Kuss, M. Larsson, S. Latronico, L. Lemoine-Goumard, M. Li, J. Longo, F. Loparco, F. Lovellette, M.N. Lubrano, P. Magill, J.D. Maldera, S. Manfreda, A. Mazziotta, M.N. McEnery, J.E. Meyer, M. Mizuno, T. Monzani, M.E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Omodei, N. Orienti, M. Orlando, E. Ormes, J.F. Palatiello, M. Paliya, V.S. Paneque, D. Perkins, J.S. Persic, M. Pesce-Rollins, M. Piron, F. Porter, T.A. Principe, G. Rainó, S. Rando, R. Rani, B. Razzaque, S. Reimer, A. Reimer, O. Reposeur, T. Sgró, C. Siskind, E.J. Spandre, G. Spinelli, P. Suson, D.J. Tajima, H. Thayer, J.B. Tibaldo, L. Torres, D.F. Tosti, G. Valverde, J. Venters, T.M. Vogel, M. Wood, K. Wood, M. Zaharijas, G. Biteau, J. Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Universita di Pisa Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Laboratoire AIM CEA-IRFU/CNRS/Universite Paris Diderot Service d'Astrophysique CEA Saclay Gif sur YvetteF-91191 France Istituto Nazionale di Fisica Nucleare Sezione di Trieste TriesteI-34127 Italy Dipartimento di Fisica Universita di Trieste TriesteI-34127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy Dipartimento di Fisica e Astronomia "G. Galilei" Universita di Padova PadovaI-35131 Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Dipartimento di Fisica 'M. Merlin" dell'Universita e del Politecnico di Bari BariI-70126 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari BariI-70126 Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics SLAC National Accelerator Laboratory Stanford University StanfordCA94305 United States Istituto Nazionale di Fisica Nucleare Sezione di Torino TorinoI-10125 Italy Dipartimento di Fisica Universita degli Studi di Torino TorinoI-10125 Italy Department of Physics and Astronomy University of Padova Vicolo Osservatorio 3 PadovaI-35122 Italy NASA Goddard Space Flight Center GreenbeltMD20771 United States Laboratoire Univers et Particules de Montpellier Universite Montpellier CNRS/IN2P3 MontpellierF-34095 France Laboratoire Leprince-Ringuet Ecole polytechnique CNRS/IN2P3 PalaiseauF-91128 France NASA Goddard Space Flight Center GreenbeltMD20771 United States INAF-Istituto di Astrosica Spaziale e Fisica Cosmica Milano via E. Bassini 15 MilanoI-20133 Italy Harvard-Smithsonian Center for Astrophysics CambridgeMA02138 United States Italian Space Agency Via del Politecnico snc Roma00133 Italy S

We present a search for spatial extension in high-latitude (jbj > 5°) sources in recent Fermi point source catalogs. The result is the Fermi High-Latitude Extended Sources Catalog, which provides source extensions (or upper limits thereof) and likelihood profiles for a suite of tested source morphologies. We find 24 extended sources, 19 of which were not previously characterized as extended. These include sources that are potentially associated with supernova remnants and star forming regions. We also found extended -ray emission in the vicinity of the Cen A radio lobes and|at GeV energies for the first time|spatially coincident with the radio emission of the SNR CTA 1, as well as from the Crab Nebula. We also searched for halos around active galactic nuclei, which are predicted from electromagnetic cascades that are induced by the e+e- pairs that are deected in intergalactic magnetic fields. These are produced when -rays interact with background radiation fields. We do not find evidence for extension in individual sources or in stacked source samples. This enables us to place limits on the ux of the extended source components, which are then used to constrain the intergalactic magnetic field a coherence length λ 10 kpc, even when conservative assumptions on the source duty cycle are made. This improves previous limits by several orders of magnitude. Copyright © 2018, The Authors. All rights reserved.

关键词： Magnetic fields

Cosmic-ray electron-positron spectrum from 7 GeV to 2 TeV with the Fermi Large Area Telescope

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Physical Review D 2017年第8期95卷 082007-082007页

作者： S. Abdollahi M. Ackermann M. Ajello W. B. Atwood L. Baldini G. Barbiellini D. Bastieri R. Bellazzini E. D. Bloom R. Bonino T. J. Brandt J. Bregeon P. Bruel R. Buehler R. A. Cameron R. Caputo M. Caragiulo D. Castro E. Cavazzuti C. Cecchi A. Chekhtman S. Ciprini J. Cohen-Tanugi F. Costanza A. Cuoco S. Cutini F. D’Ammando F. de Palma R. Desiante S. W. Digel N. Di Lalla M. Di Mauro L. Di Venere P. S. Drell A. Drlica-Wagner C. Favuzzi W. B. Focke S. Funk P. Fusco F. Gargano D. Gasparrini N. Giglietto F. Giordano M. Giroletti D. Green L. Guillemot S. Guiriec A. K. Harding T. Jogler G. Jóhannesson T. Kamae M. Kuss G. La Mura L. Latronico F. Longo F. Loparco P. Lubrano S. Maldera D. Malyshev A. Manfreda M. N. Mazziotta P. F. Michelson N. Mirabal W. Mitthumsiri T. Mizuno A. A. Moiseev M. E. Monzani A. Morselli I. V. Moskalenko M. Negro E. Nuss E. Orlando D. Paneque J. S. Perkins M. Pesce-Rollins F. Piron G. Pivato T. A. Porter G. Principe S. Rainò R. Rando M. Razzano A. Reimer O. Reimer C. Sgrò D. Simone E. J. Siskind F. Spada G. Spandre P. Spinelli H. Tajima J. B. Thayer L. Tibaldo D. F. Torres E. Troja M. Wood A. Worley G. Zaharijas S. Zimmer Department of Physical Sciences Hiroshima University Higashi-Hiroshima Hiroshima 739-8526 Japan Deutsches Elektronen Synchrotron DESY D-15738 Zeuthen Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics Clemson South Carolina 29634-0978 USA Santa Cruz Institute for Particle Physics Department of Physics and Department of Astronomy and Astrophysics University of California at Santa Cruz Santa Cruz California 95064 USA Università di Pisa and Istituto Nazionale di Fisica Nucleare Sezione di Pisa I-56127 Pisa Italy Istituto Nazionale di Fisica Nucleare Sezione di Trieste I-34127 Trieste Italy Dipartimento di Fisica Università di Trieste I-34127 Trieste Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova I-35131 Padova Italy Dipartimento di Fisica e Astronomia “G. Galilei ” Università di Padova I-35131 Padova Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa I-56127 Pisa Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics and SLAC National Accelerator Laboratory Stanford University Stanford California 94305 USA Istituto Nazionale di Fisica Nucleare Sezione di Torino I-10125 Torino Italy Dipartimento di Fisica Università degli Studi di Torino I-10125 Torino Italy NASA Goddard Space Flight Center Greenbelt Maryland 20771 USA Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 F-34095 Montpellier France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 F-91128 Palaiseau France Dipartimento di Fisica “M. Merlin” dell’Università e del Politecnico di Bari I-70126 Bari Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari I-70126 Bari Italy Agenzia Spaziale Italiana (ASI) Science Data Center I-00133 Roma Italy Istituto Nazionale di Fisica Nucleare Sezione di Perugia I-06123 Perugia Italy Dipartimento di Fisica Università degli Studi di Perugia I-06123 Perugia Italy College of Science

We present a measurement of the cosmic-ray electron+positron spectrum between 7 GeV and 2 TeV performed with almost seven years of data collected with the Fermi Large Area Telescope. We find that the spectrum is well fit by a broken power law with a break energy at about 50 GeV. Above 50 GeV, the spectrum is well described by a single power law with a spectral index of 3.07±0.02(stat+syst)±0.04(energy measurement). An exponential cutoff lower than 1.8 TeV is excluded at 95% CL.

关键词： Cosmic ray & astroparticle detectors Cosmic ray composition & spectra Cosmic ray sources Particle astrophysics

Search for extended sources in the galactic plane using 6 years of Fermi-Large area telescope pass 8 data above 10 GeV

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arXiv 2017年

作者： Ackermann, M. Ajello, M. Baldini, L. Ballet, J. Barbiellini, G. Bastieri, D. Bellazzini, R. Bissaldi, E. Bloom, E.D. Bonino, R. Bottacini, E. Brandt, T.J. Bregeon, J. Bruel, P. Buehler, R. Cameron, R.A. Caragiulo, M. Caraveo, P.A. Castro, D. Cavazzuti, E. Cecchi, C. Charles, E. Chekhtman, A. Cheung, C.C. Chiaro, G. Ciprini, S. Cohen, J.M. Costantin, D. Costanza, F. Cutini, S. D’Ammando, F. de Palma, F. Desiante, R. Digel, S.W. Di Lalla, N. Di Mauro, M. Di Venere, L. Favuzzi, C. Fegan, S.J. Ferrara, E.C. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giordano, F. Giroletti, M. Green, D. Grenier, I.A. Grondin, M.-H. Guillemot, L. Guiriec, S. Harding, A.K. Hays, E. Hewitt, J.W. Horan, D. Hou, X. Jóhannesson, G. Kamae, T. Kuss, M. la Mura, G. Larsson, S. Lemoine-Goumard, M. Li, J. Longo, F. Loparco, F. Lubrano, P. Magill, J.D. Maldera, S. Malyshev, D. Manfreda, A. Mazziotta, M.N. Michelson, P.F. Mitthumsiri, W. Mizuno, T. Monzani, M.E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Ohsugi, T. Omodei, N. Orienti, M. Orlando, E. Ormes, J.F. Paliya, V.S. Paneque, D. Perkins, J.S. Persic, M. Pesce-Rollins, M. Petrosian, V. Piron, F. Porter, T.A. Principe, G. Rainò, S. Rando, R. Razzano, M. Razzaque, S. Reimer, A. Reimer, O. Reposeur, T. Sgrò, C. Simone, D. Siskind, E.J. Spada, F. Spandre, G. Spinelli, P. Suson, D.J. Tak, D. Thayer, J.B. Thompson, D.J. Torres, D.F. Tosti, G. Troja, E. Vianello, G. Wood, K.S. Wood, M. Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Università di Pisa Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Laboratoire AIM CEA-IRFU CNRS Université Paris Diderot Service d’Astrophysique CEA Saclay Gif sur YvetteF-91191 France Istituto Nazionale di Fisica Nucleare Sezione di Trieste TriesteI-34127 Italy Dipartimento di Fisica Università di Trieste TriesteI-34127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy Dipartimento di Fisica e Astronomia "G. Galilei" Università di Padova PadovaI-35131 Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari BariI-70126 Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics SLAC National Accelerator Laboratory Stanford University StanfordCA94305 United States Istituto Nazionale di Fisica Nucleare Sezione di Torino TorinoI-10125 Italy Dipartimento di Fisica Università degli Studi di Torino TorinoI-10125 Italy NASA Goddard Space Flight Center GreenbeltMD20771 United States Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 MontpellierF-34095 France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France Dipartimento di Fisica "M. Merlin" dell’Università e del Politecnico di Bari BariI-70126 Italy INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Milano via E. Bassini 15 MilanoI-20133 Italy Science Data Center RomaI-00133 Italy Istituto Nazionale di Fisica Nucleare Sezione di Perugia PerugiaI-06123 Italy Dipartimento di Fisica Università degli Studi di Perugia PerugiaI-06123 Italy College of Science George Mason University Fairfax VA22030 United States Naval Research Laboratory Washi

The spatial extension of a γ-ray source is an essential ingredient to determine its spectral properties as well as its potential multi-wavelength counterpart. The capability to spatially resolve γ-ray sources is greatly improved by the newly delivered Fermi-Large Area Telescope (LAT) Pass 8 event-level analysis which provides a greater acceptance and an improved point spread function, two crucial factors for the detection of extended sources. Here, we present a complete search for extended sources located within 7◦ from the Galactic plane, using 6 years of Fermi-LAT data above 10 GeV. We find 46 extended sources and provide their morphological and spectral characteristics. This constitutes the first catalog of hard Fermi-LAT extended sources, named the Fermi Galactic Extended Source Catalog, which allows a thorough study of the properties of the Galactic plane in the sub-TeV domain. Copyright © 2017, The Authors. All rights reserved.

关键词： Gamma rays

Cosmic-ray electron+positron spectrum from 7 GeV to 2 TeV with the Fermi Large Area Telescope

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arXiv 2017年

作者： Abdollahi, S. Ackermann, M. Ajello, M. Atwood, W.B. Baldini, L. Barbiellini, G. Bastieri, D. Bellazzini, R. Bloom, E.D. Bonino, R. Brandt, T.J. Bregeon, J. Bruel, P. Buehler, R. Cameron, R.A. Caputo, R. Caragiulo, M. Castro, D. Cavazzuti, E. Cecchi, C. Chekhtman, A. Ciprini, S. Cohen-Tanugi, J. 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. Drlica-Wagner, A. Favuzzi, C. Focke, W.B. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giordano, F. Giroletti, M. Green, D. Guillemot, L. Guiriec, S. Harding, A.K. Jogler, T. Jóhannesson, G. Kamae, T. Kuss, M. la Mura, G. Latronico, L. Longo, F. Loparco, F. Lubrano, P. Maldera, S. Malyshev, D. Manfreda, A. Mazziotta, M.N. Michelson, P.F. Mirabal, N. Mitthumsiri, W. Mizuno, T. Moiseev, A.A. Monzani, M.E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Orlando, E. Paneque, D. Perkins, J.S. Pesce-Rollins, M. Piron, F. Pivato, G. Porter, T.A. Principe, G. Rainò, S. Rando, R. Razzano, M. Reimer, A. Reimer, O. Sgrò, C. Simone, D. Siskind, E.J. Spada, F. Spandre, G. Spinelli, P. Tajima, H. Thayer, J.B. Tibaldo, L. Torres, D.F. Troja, E. Wood, M. Worley, A. Zaharijas, G. Zimmer, S. Department of Physical Sciences Hiroshima University Higashi-HiroshimaHiroshima739-8526 Japan Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Santa Cruz Institute for Particle Physics Department of Physics Department of Astronomy and Astrophysics University of California at Santa Cruz Santa CruzCA95064 United States Università di Pisa Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Trieste TriesteI-34127 Italy Dipartimento di Fisica Università di Trieste TriesteI-34127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy Dipartimento di Fisica e Astronomia "G. Galilei" Università di Padova PadovaI-35131 Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics SLAC National Accelerator Laboratory Stanford University StanfordCA94305 United States Istituto Nazionale di Fisica Nucleare Sezione di Torino TorinoI-10125 Italy Dipartimento di Fisica Università degli Studi di Torino TorinoI-10125 Italy NASA Goddard Space Flight Center GreenbeltMD20771 United States Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 MontpellierF-34095 France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France Dipartimento di Fisica "M. Merlin" dell’Università e del Politecnico di Bari BariI-70126 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari BariI-70126 Italy Science Data Center RomaI-00133 Italy Istituto Nazionale di Fisica Nucleare Sezione di Perugia PerugiaI-06123 Italy Dipartimento di Fisica Università degli Studi di Perugia PerugiaI-06123 Italy College of Science George Mason University Fairfax VA22

We present a measurement of the cosmic-ray electron+positron spectrum between 7 GeV and 2 TeV performed with almost seven years of data collected with the Fermi Large Area Telescope. We find that the spectrum is well fit by a broken power law with a break energy at about 50 GeV. Above 50 GeV, the spectrum is well described by a single power law with a spectral index of 3.07 ± 0.02 (stat+syst) ± 0.04 (energy measurement). An exponential cutoff lower than 1.8 TeV is excluded at 95% CL. Copyright © 2017, The Authors. All rights reserved.

关键词： Cosmology