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10th Annual Conference of Advanced Computer Architecture, ACA 2014

作者： Dai, Zhuofang Zhang, Zheng Wang, Haojun Li, Yi Zhang, Weihua Software School Fudan University Shanghai China Shanghai Key Laboratory of Data Science Fudan University Shanghai China Parallel Processing Institute Fudan University Shanghai 201203 China State Key Laboratory of Mathematic Engineering and Advanced Computing Zhengzhou 450001 China

ISBN: (纸本)9783662444900

In order to harness abundant hardware resources, parallel programming has become a necessity in multicore era. However, parallel programs are prone to concurrency bugs, especially data races. Even worse, current software tools always suffer from both large runtime overheads and poor scalability, while most of hardware supports for race detection are not available in parallel programming. Therefore, it has been a challenge that how to introduce a practical and fast race detection tools. Nowadays, GPUs with massive parallel computation resources have become one of the most popular hardware platforms. Hence, the prevalence of GPU architectures has opened an opportunity of accelerating data race detection. In this paper, we first have a deeply analysis on data race detection algorithms like happens-before and observe that these algorithms have very good computation and data parallelism. Based on the observation, we propose Grace, a software approach that leverages massive parallelism computation units of GPU architectures to accelerate data race detection. Grace deploys detection, the most computation intensive workload, on GPU to fully utilize the computation resource in GPU. Moreover, Grace leverages coarse-grained pipeline parallelism and data parallelism through exploiting the computation resource in multi-core CPUs to further improve performance. Experimental results show that Grace is fast and scalable. It achieves over 80x speedup compared to the sequential version even under a 128-thread configuration. © Springer-Verlag Berlin Heidelberg 2014.

关键词： Graphics processing unit

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

arXiv

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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

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Social evolutionary games

Social evolutionary games

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International Conference on Game Theory for Networks, GameNets

作者： Jianye Yu Yuanzhuo Wang Xiao!ong Jin Xueqi Cheng CAS Key Laboratory of Network Data Science and Technology Institute of Computing Technology Chinese Academy of Sciences University of Chinese Academy of Sciences Beijing China

In this paper, we introduce a framework of social evolutionary games (SEG) for investigating the evolution of social networks. In a SEG, a coevolutionary mechanism is adopted by agents who aim to improve his short-term utility and long-term reputation. Two examples are presented to demonstrate SEG, prisoner's dilemma game for pairwise interaction and public goods game for group interaction. Numerical simulations are performed on the two examples with different parameter settings, and the results indicates that SEG can be used as a metaphor for investigating the evolution of social networks in some scenarios.

关键词： Microscopy

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Big data: Prospects and Challenges

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Vikalpa 2015年第1期40卷 74 - 96页

作者： Janakiraman Moorthy Rangin Lahiri Neelanjan Biswas Dipyaman Sanyal Jayanthi Ranjan Krishnadas Nanath Pulak Ghosh (Coordinator) Director and Professor of Marketing at the Institute of Management Technology Dubai. Earlier he was Professor of Marketing at the IIM Calcutta and IIM Lucknow. He received his PhD from IIM Ahmedabad. His recent research papers were published in the leading scholarly ournals such as Marketing Science British Food Journal Journal of Information Technology Case and Application Research Journal of Database Marketing & Customer Strategy Management. He has wide experience in the banking and investment industry. He was earlier the Global Research and Project Director of the Institute for Customer Relationship Management Atlanta USA. He was the Convener of the prestigious CAT Exam 2011. e-mail: Practice Director leading Atos India's CRM practice while supporting Strategic Business Development for North American Market. With an experience of more than 15 years Rangin has worked extensively as a Business Consultant in Information Technology (Sales Automation Marketing & Service Management area) Customer Data Management and CRM Analytics. e-mail: Business Consultant at Atos with extensive experience in Business Analysis Risk Management Analytics Business Development Presales Solution Ideation on Enterprise Data Management Enterprise Reference Data and Master Data Management area. e-mail: founder and CEO of dono consulting a boutique quantitative analytics and investment research firm. He has worked for leading financial firms in New York and India including Dow Jones Blackstone Sorin Capital (VP Quantitative Modeling) and Thomson Reuters (Head of Real Estate Analytics). A CFA charter holder and Commonwealth Scholar Deep has an MS (Applied Economics) from University of Texas Dallas and an MA (Economics) from Jadavpur University e-mail: Professor in the Information Systems Group of the Institute of Management Technology Ghaziabad. Her PhD is in the field of data mining from Jamia Millia Islamia Central University India. She has published five edited books. She is serving on the editorial b

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GAMMA-RAY BLAZARS WITHIN THE FIRST 2 BILLION YEARS

arXiv

引用

arXiv 2017年

作者： Ackermann, M. Ajello, M. Baldini, L. Ballet, J. Barbiellini, G. Bastieri, D. Becerra Gonzalez, J. Bellazzini, R. Bissaldi, E. Blandford, R.D. Bloom, E.D. Bonino, R. Bottacini, E. Bregeon, J. Bruel, P. Buehler, R. Buson, S. Cameron, R.A. Caragiulo, M. Caraveo, P.A. Cavazzuti, E. Cecchi, C. Cheung, C.C. Chiang, J. Chiaro, G. Ciprini, S. Conrad, J. Costantin, D. Costanza, F. Cutini, S. D’Ammando, F. Palma, F.D.E. Desiante, R. Digel, S.W. Lalla, N.D.I. Mauro, M.D.I. Venere, L.D.I. Domínguez, A. Drell, P.S. Favuzzi, C. Fegan, S.J. Ferrara, E.C. Finke, J. Focke, W.B. 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. Hartmann, D.H. Hays, E. Horan, D. Jogler, T. Jóhannesson, G. Johnson, A.S. Kuss, M. Mura, G.L.A. Larsson, S. Latronico, L. Li, J. Longo, F. Loparco, F. Lovellette, M.N. Lubrano, P. Magill, J.D. Maldera, S. Manfreda, A. Marcotulli, L. Mazziotta, M.N. Michelson, P.F. Mirabal, N. Mitthumsiri, W. Mizuno, T. Monzani, M.E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Ohsugi, T. Ojha, R. Omodei, N. Orienti, M. Orlando, E. Ormes, J.F. Paliya, V.S. Paneque, D. Perkins, J.S. Persic, M. Pesce-Rollins, M. Piron, F. Porter, T.A. Principe, G. Rainò, S. Rando, R. Rani, B. Razzano, M. Razzaque, S. Reimer, A. Torres, D.F. Torresi, E. Tosti, G. Troja, E. Vianello, G. Wood, K.S. Reimer, O. Romani, R.W. Sgrò, C. Simone, D. Siskind, E.J. Spada, F. Spandre, G. Spinelli, P. Stalin, C.S. Stawarz, L. Suson, D.J. Takahashi, M. Tanaka, K. Thayer, J.B. Thompson, D.J. 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 NASA Goddard Space Flight Center GreenbeltMD20771 United States Department of Physics Department of Astronomy University of Maryland College ParkMD20742 United States 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 Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 MontpellierF-34095 France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France NASA Postdoctoral Program Fellow United States 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

The detection of high-redshift (z >3) blazars enables the study of the evolution of the most luminous relativistic jets over cosmic time. More importantly, high-redshift blazars tend to host massive black holes and can be used to constrain the space density of heavy black holes in the early Universe. Here, we report the first detection with the Fermi-Large Area Telescope of five γ-ray emitting blazars beyond z = 3.1, more distant than any blazars previously detected in γ-rays. Among these five objects, NVSS J151002+570243 is now the most distant known γ-ray emitting blazar at z = 4.31. These objects have steeply falling γ-ray spectral energy distributions (SEDs) and, those that have been observed in X-rays, a very hard X-ray spectrum, both typical of powerful blazars. Their Compton dominance (ratio of the inverse Compton to synchrotron peak luminosities) is also very large (> 20). All of these properties place these objects among the most extreme members of the blazar population. Their optical spectra and the modeling of their optical-UV SEDs confirm that these objects harbor massive black holes (MBH ∼ 108−10M.). We find that, at z ≈ 4, the space density of > 109M. black holes hosted in radio-loud and radio-quiet active galactic nuclei are similar, implying that radio-loudness may play a key role in rapid black hole growth in the early Universe. Copyright © 2017, The Authors. All rights reserved.

关键词： Cosmology

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Characterizing the population of pulsars in the inner galaxy with the fermi large area telescope

arXiv

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arXiv 2017年

作者： Ajello, M. Baldini, L. Ballet, J. Barbiellini, G. Bastieri, D. Bellazzini, R. Bissaldi, E. Blandford, R.D. Bloom, E.D. Bottacini, E. Bregeon, J. Bruel, P. Buehler, R. Cameron, R.A. Caputo, R. Caragiulo, M. Caraveo, P.A. Cavazzuti, E. Cecchi, C. Charles, E. Chekhtman, A. Chiaro, G. Ciprini, S. Costantin, D. Costanza, F. D’Ammando, F. Palma, F.D.E. Desiante, R. Digel, S.W. Lalla, N.D.I. Mauro, M.D.I. Venere, L.D.I. Favuzzi, C. Ferrara, E.C. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giordano, F. Giroletti, M. Green, D. Guillemot, L. Guiriec, S. Harding, A.K. Horan, D. Jóhannesson, G. Kuss, M. Mura, G.L.A. Larsson, S. Latronico, L. Li, J. Longo, F. Loparco, F. Lovellette, M.N. Lubrano, P. Maldera, S. Malyshev, D. Marcotulli, L. Martin, P. Mazziotta, M.N. Meyer, M. Michelson, P.F. Mirabal, N. Mizuno, T. Monzani, M.E. Morselli, A. Moskalenko, I.V. Nuss, E. Omodei, N. Orienti, M. Orlando, E. Palatiello, M. Paliya, V.S. Paneque, D. Perkins, J.S. Persic, M. Pesce-Rollins, M. Piron, F. Principe, G. Rainò, S. Rando, R. Razzano, M. Reimer, A. Reimer, O. Parkinson, P.M. Saz Sgrò, C. Siskind, E.J. Smith, D.A. Spada, F. Spandre, G. Spinelli, P. Tajima, H. Thayer, J.B. Thompson, D.J. Tibaldo, L. Torres, D.F. Troja, E. Vianello, G. Wood, K. Wood, M. Zaharijas, G. 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 Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 MontpellierF-34095 France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany 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 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 Naval Research DC20375 United States ASI Space Science Data Center Via del Politecnico snc Roma00133 Italy INAF Istituto di Radioastronomia BolognaI-40129 Italy Dipartimento di Ast

An excess of γ-ray emission from the Galactic Center (GC) region with respect to predictions based on a variety of interstellar emission models and γ-ray source catalogs has been found by many groups using data from the Fermi Large Area Telescope (LAT). Several interpretations of this excess have been invoked. In this paper we search for members of an unresolved population of γ-ray pulsars located in the inner Galaxy that are predicted by the interpretation of the GC excess as being due to a population of such sources. We use cataloged LAT sources to derive criteria that efficiently select pulsars with very small contamination from blazars. We search for point sources in the inner 40◦ × 40◦ region of the Galaxy, derive a list of approximately 400 sources, and apply pulsar selection criteria to extract pulsar candidates among our source list. We performed the entire data analysis chain with two different interstellar emission models (IEMs), and found a total of 135 pulsar candidates, of which 66 were selected with both IEMs. Copyright © 2017, The Authors. All rights reserved.

关键词： Pulsars

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The Fermi galactic center GeV excess and implications for dark matter

arXiv

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arXiv 2017年

作者： Ackermann, M. Ajello, M. Albert, A. Atwood, W.B. 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. Burnett, T.H. Cameron, R.A. Caputo, R. Caragiulo, M. Caraveo, P.A. Cavazzuti, E. Cecchi, C. Charles, E. Chekhtman, A. Chiang, J. Chiappo, A. Chiaro, G. Ciprini, S. Conrad, J. Costanza, F. Cuoco, A. Cutini, S. D’Ammando, F. de Palma, F. Desiante, R. Digel, S.W. Lalla, N. Di Mauro, M. Di Venere, L. Di Drell, P.S. Favuzzi, C. Fegan, S.J. Ferrara, E.C. Focke, W.B. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giordano, F. Giroletti, M. Glanzman, T. Gomez-Vargas, G.A. Green, D. Grenier, I.A. Grove, J.E. Guillemot, L. Guiriec, S. Gustafsson, M. Harding, A.K. Hays, E. Hewitt, J.W. Horan, D. Jogler, T. Johnson, A.S. Kamae, T. Kocevski, D. Kuss, M. Mura, G. La Larsson, S. Latronico, L. Li, J. Longo, F. Loparco, F. Lovellette, M.N. Lubrano, P. Magill, J.D. Maldera, S. Malyshev, D. Manfreda, A. Martin, P. Mazziotta, M.N. Michelson, P.F. Mirabal, N. Mitthumsiri, W. Mizuno, T. Moiseev, A.A. Monzani, M.E. Morselli, A. Negro, M. Nuss, E. Ohsugi, T. Orienti, M. Orlando, E. Ormes, J.F. Paneque, D. Perkins, J.S. Persic, M. Pesce-Rollins, M. Piron, F. Principe, G. Rainò, S. Rando, R. Razzano, M. Razzaque, S. Reimer, A. Reimer, O. Sánchez-Conde, M. Sgrò, C. Simone, D. Siskind, E.J. Spada, F. Spandre, G. Spinelli, P. Suson, D.J. Tajima, H. Tanaka, K. Thayer, J.B. Tibaldo, L. Torres, D.F. Troja, E. Uchiyama, Y. Vianello, G. Wood, K.S. Wood, M. Zaharijas, G. Zimmer, S. 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 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 Department of Physics University of Washington SeattleWA98195-1560 United States 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 M

The region around the Galactic center (GC) is now well established to be brighter at energies of a few GeV than expected from conventional models of diffuse gamma-ray emission and catalogs of known gamma-ray sources. We study the GeV excess using 6.5 years of data from the Fermi Large Area Telescope. We characterize the uncertainty of the GC excess spectrum and morphology due to uncertainties in cosmic-ray source distributions and propagation, uncertainties in the distribution of interstellar gas in the Milky Way, and uncertainties due to a potential contribution from the Fermi bubbles. We also evaluate uncertainties in the excess properties due to resolved point sources of gamma rays. The Galactic center is of particular interest as it would be expected to have the brightest signal from annihilation of weakly interacting massive dark matter particles. However, control regions along the Galactic plane, where a dark-matter signal is not expected, show excesses of similar amplitude relative to the local background. Based on the magnitude of the systematic uncertainties, we conservatively report upper limits for the annihilation cross section as function of particle mass and annihilation channel. Copyright © 2017, The Authors. All rights reserved.

关键词： Gamma rays

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3FHL: The Third Catalog of Hard Fermi-LAT Sources

arXiv

引用

arXiv 2017年

作者： Ajello, M. Atwood, W.B. Baldini, L. Ballet, J. Barbiellini, G. Bastieri, D. Bellazzini, R. Bissaldi, E. Blandford, R.D. Bloom, E.D. Bonino, R. Bregeon, J. Britto, R.J. Bruel, P. Buehler, R. Buson, S. Cameron, R.A. Caputo, R. Caragiulo, M. Caraveo, P.A. Cavazzuti, E. Cecchi, C. Charles, E. Chekhtman, A. Cheung, C.C. Chiaro, G. Ciprini, S. Cohen, J.M. Costantin, D. 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. Domínguez, A. Drell, P.S. Dumora, D. Favuzzi, C. Fegan, S.J. Ferrara, E.C. Fortin, P. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giommi, P. Giordano, F. Giroletti, M. Glanzman, T. Green, D. Grenier, I.A. Grondin, M.-H. Grove, J.E. Guillemot, L. Guiriec, S. Harding, A.K. Hays, E. Hewitt, J.W. Horan, D. Jóhannesson, G. Kensei, S. Kuss, M. la Mura, G. Larsson, S. Latronico, L. Lemoine-Goumard, M. Li, J. Longo, F. Loparco, F. Lott, B. Lubrano, P. Magill, J.D. Maldera, S. Manfreda, A. Mazziotta, M.N. McEnery, J.E. Meyer, M. Michelson, P.F. Mirabal, N. Mitthumsiri, W. Mizuno, T. Moiseev, A.A. Monzani, M.E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Ohsugi, T. Omodei, N. Orienti, M. Orlando, E. Palatiello, M. Paliya, V.S. Paneque, D. Perkins, J.S. Persic, M. Pesce-Rollins, M. Piron, F. Porter, T.A. Principe, G. Rainò, S. Rando, R. Razzano, M. Razzaque, S. Reimer, A. Reimer, O. Reposeur, T. Saz Parkinson, P.M. Sgrò, C. Simone, D. Siskind, E.J. Spada, F. Spandre, G. Spinelli, P. Stawarz, L. Suson, D.J. Takahashi, M. Tak, D. Thayer, J.G. Thayer, J.B. Thompson, D.J. Torres, D.F. Torresi, E. Troja, E. Vianello, G. Wood, K. Wood, M. 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 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 Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 MontpellierF-34095 France Department of Physics University of the Free State P.O. Box 339 Bloemfontein9300 South Africa Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany 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 As

We present a catalog of sources detected above 10 GeV by the Fermi Large Area Telescope (LAT) in the first 7 years of data using the Pass 8 event-level analysis. This is the Third Catalog of Hard Fermi-LAT Sources (3FHL), containing 1556 objects characterized in the 10 GeV–2 TeV energy range. The sensitivity and angular resolution are improved by factors of 3 and 2 relative to the previous LAT catalog at the same energies (1FHL). The vast majority of detected sources (79%) are associated with extragalactic counterparts at other wavelengths, including 16 sources located at very high redshift (z > 2). Eight percent of the sources have Galactic counterparts and 13% are unassociated (or associated with a source of unknown nature). The high-latitude sky and the Galactic plane are observed with a flux sensitivity of 4.4 to 9.5 ×10−11 ph cm−2 s−1, respectively (this is approximately 0.5 % and 1 % of the Crab Nebula flux above 10 GeV). The catalog includes 214 new γ-ray sources. The substantial increase in the number of photons (more than 4 times relative to 1FHL and 10 times to 2FHL) also allows us to measure significant spectral curvature for 32 sources and find flux variability for 163 of them. Furthermore, we estimate that for the same flux limit of 10−12 erg cm−2 s−1, the energy range above 10 GeV has twice as many sources as above 50 GeV, highlighting the importance, for future Cherenkov telescopes, of lowering the energy threshold as much as possible. Copyright © 2017, The Authors. All rights reserved.

关键词： Gamma rays

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science with e-ASTROGAM: A space mission for MeV-GeV gamma-ray astrophysics

arXiv

引用

arXiv 2017年

作者： de Angelis, A. Tatischeff, V. Grenier, I.A. McEnery, J. Mallamaci, M. Tavani, M. Oberlack, U. Hanlon, L. Walter, R. Argan, A. von Ballmoos, P. Bulgarelli, A. Bykov, A. Hernanz, M. Kanbach, G. Kuvvetli, I. Pearce, M. Zdziarski, A. Conrad, J. Ghisellini, G. Harding, A. Isern, J. Leising, M. Longo, F. Madejski, G. Martinez, M. Mazziotta, M.N. Paredes, J.M. Pohl, M. Rando, R. Razzano, M. Aboudan, A. Ackermann, M. Addazi, A. Ajello, M. Albertus, C. Álvarez, J.M. Ambrosi, G. Antón, S. Antonelli, L.A. Babic, A. Baibussinov, B. Balbo, M. Baldini, L. Balman, S. Bambi, C. Barres de Almeida, U. Barrio, J.A. Bartels, R. Bastieri, D. Bednarek, W. Bernard, D. Bernardini, E. Bernasconi, T. Bertucci, B. Biland, A. Bissaldi, E. Boettcher, M. Bonvicini, V. Bosch-Ramon, V. Bottacini, E. Bozhilov, V. Bretz, T. Branchesi, M. Brdar, V. Bringmann, T. Brogna, A. Budtz-Jørgensen, C. Busetto, G. Buson, S. Busso, M. Caccianiga, A. Camera, S. Campana, R. Caraveo, P. Cardillo, M. Carlson, P. Celestin, S. Cermeño, M. Chen, A. Cheung, C.C. Churazov, E. Ciprini, S. Coc, A. Colafrancesco, S. Coleiro, A. Collmar, W. Coppi, P. Curado da Silva, R. Cutini, S. D'Ammando, F. de Lotto, B. de Martino, D. de Rosa, A. Del Santo, M. Delgado, L. Diehl, R. Dietrich, S. Dolgov, A.D. Domínguez, A. Dominis Prester, D. Donnarumma, I. Dorner, D. Doro, M. Dutra, M. Elsaesser, D. Fabrizio, M. Fernández-Barral, A. Fioretti, V. Foffano, L. Formato, V. Fornengo, N. Foschini, L. Franceschini, A. Franckowiak, A. Funk, S. Fuschino, F. Gaggero, D. Galanti, G. Gargano, F. Gasparrini, D. Gehrz, R. Giammaria, P. Giglietto, N. Giommi, P. Giordano, F. Giroletti, M. Ghirlanda, G. Godinovic, N. Gouiffés, C. Grove, J.E. Hamadache, C. Hartmann, D.H. Hayashida, M. Hryczuk, A. Jean, P. Johnson, T. José, J. Kaufmann, S. Khelifi, B. Kiener, J. Knödlseder, J. Kole, M. Kopp, J. Kozhuharov, V. Labanti, C. Lalkovski, S. Laurent, P. Limousin, O. Linares, M. Lindfors, E. Lindner, M. Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy INAF Osservatorio Astronomico di Padova PadovaI-35122 Italy Dipartimento di Matematica Informatica e Fisica Università di Udine UdineI-33100 Italy Laboratorio de Instrumentaçao e Particulas Instituto Superior Tecnico Lisboa Portugal CSNSM CNRS University of Paris Sud OrsayF-91405 France Laboratoire AIM CEA-IRFU CNRS Université Paris Diderot C.E.A. Saclay France NASA Goddard Space Flight Center GreenbeltMD20771 United States INAF/IAPS via del Fosso del Cavaliere 100 RomaI-00133 Italy University of Roma "Tor Vergata" RomaI-00133 Italy Istituto Nazionale di Fisica Nucleare Sezione di Roma "Tor Vergata" RomaI-00133 Italy Institute of Physics and PRISMA Excellence Cluster Johannes Gutenberg University Mainz Mainz55099 Germany School of Physics University College Dublin Ireland University of Geneva Switzerland INAF Headquarters Viale del Parco Mellini 84 RomaI-00136 Italy IRAP Toulouse 9 av. du Colonel-Roche - BP 44 346 Toulouse Cedex 4F-31028 France INAF/OAS-Bologna Via Gobetti 93 BolognaI-40129 Italy Ioffe Institute St.Petersburg194021 Russia 08193 Spain Max-Planck-Institut fur Extraterrestrische Physik Postfach 1312 Garching85741 Germany DTU Space National Space Institute Technical University of Denmark Kgs. Lyngby Denmark Stockholm10691 Sweden Nicolaus Copernicus Astronomical Center Polish Academy of Sciences Bartycka 18 WarszawaPL-00-716 Poland Oskar Klein Centre for Cosmoparticle Physics Fysikum Stockholm University AlbaNova University Centre StockholmSE-10961 Sweden INAF - Osservatorio Astronomico di Brera MerateI-23807 Italy Campus UAB Carrer Can Magrans s/n Cerdanyola del Valles BarcelonaE-08193 Spain Department of Physics and Astronomy Clemson University ClemsonSC29634 United States Dipartimento di Fisica Università di Trieste TriesteI-34127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Trieste TriesteI-34127 Italy W.

e-ASTROGAM ('enhanced ASTROGAM') is a breakthrough Observatory space mission, with a detector composed by a Silicon tracker, a calorimeter, and an anticoincidence system, dedicated to the study of the non-thermal Universe in the photon energy range from 0.3 MeV to 3 GeV - the lower energy limit can be pushed to energies as low as 150 keV for the tracker, and to 30 keV for calorimetric detection. The mission is based on an advanced space-proven detector technology, with unprecedented sensitivity, angular and energy resolution, combined with polarimetric capability. Thanks to its performance in the MeV-GeV domain, substantially improving its predecessors, e-ASTROGAM will open a new window on the non-thermal Universe, making pioneering observations of the most powerful Galactic and extragalactic sources, elucidating the nature of their relativistic outflows and their effects on the surroundings. With a line sensitivity in the MeV energy range one to two orders of magnitude better than previous generation instruments, e-ASTROGAM will determine the origin of key isotopes fundamental for the understanding of supernova explosion and the chemical evolution of our Galaxy. The mission will provide unique data of significant interest to a broad astronomical community, complementary to powerful observatories such as LIGO-Virgo-GEO600-KAGRA, SKA, ALMA, E-ELT, TMT, LSST, JWST, Athena, CTA, IceCube, KM3NeT, and LISA. Copyright © 2017, The Authors. All rights reserved.

关键词： Germanium alloys

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Search for Spectral Irregularities due to Photon–Axionlike-Particle Oscillations with the Fermi Large Area Telescope

引用

Physical Review Letters 2016年第16期116卷 161101-161101页

作者： M. Ajello A. Albert B. Anderson L. Baldini G. Barbiellini D. Bastieri R. Bellazzini E. Bissaldi R. D. Blandford E. D. Bloom R. Bonino E. Bottacini J. Bregeon P. Bruel R. Buehler G. A. Caliandro R. A. Cameron M. Caragiulo P. A. Caraveo C. Cecchi A. Chekhtman S. Ciprini J. Cohen-Tanugi J. Conrad F. Costanza F. D’Ammando A. de Angelis F. de Palma R. Desiante M. Di Mauro L. Di Venere A. Domínguez P. S. Drell C. Favuzzi W. B. Focke A. Franckowiak Y. Fukazawa S. Funk P. Fusco F. Gargano D. Gasparrini N. Giglietto T. Glanzman G. Godfrey S. Guiriec D. Horan G. Jóhannesson M. Katsuragawa S. Kensei M. Kuss S. Larsson L. Latronico J. Li L. Li F. Longo F. Loparco P. Lubrano G. M. Madejski S. Maldera A. Manfreda M. Mayer M. N. Mazziotta M. Meyer P. F. Michelson N. Mirabal T. Mizuno M. E. Monzani A. Morselli I. V. Moskalenko S. Murgia M. Negro E. Nuss C. Okada E. Orlando J. F. Ormes D. Paneque J. S. Perkins M. Pesce-Rollins F. Piron G. Pivato T. A. Porter S. Rainò R. Rando M. Razzano A. Reimer M. Sánchez-Conde C. Sgrò D. Simone E. J. Siskind F. Spada G. Spandre P. Spinelli H. Takahashi J. B. Thayer D. F. Torres G. Tosti E. Troja Y. Uchiyama K. S. Wood M. Wood G. Zaharijas S. Zimmer Department of Physics and Astronomy Clemson University Kinard Lab of Physics Clemson South Carolina 29634-0978 USA 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 Department of Physics Stockholm University AlbaNova SE-106 91 Stockholm Sweden The Oskar Klein Centre for Cosmoparticle Physics AlbaNova SE-106 91 Stockholm Sweden 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 Istituto Nazionale di Fisica Nucleare Sezione di Bari I-70126 Bari Italy Istituto Nazionale di Fisica Nucleare Sezione di Torino I-10125 Torino Italy Dipartimento di Fisica Generale “Amadeo Avogadro ” Università degli Studi di Torino I-10125 Torino Italy Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 Montpellier France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 Palaiseau France Deutsches Elektronen Synchrotron DESY D-15738 Zeuthen Germany Consorzio Interuniversitario per la Fisica Spaziale (CIFS) I-10133 Torino Italy Dipartimento di Fisica “M. Merlin” dell’Università e del Politecnico di Bari I-70126 Bari Italy INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica I-20133 Milano 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 George Mason University Fairfax Virginia 22030 USA and Naval Research Laborato

We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the γ-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5×10−12 GeV−1 for ALP masses 0.5≲ma≲5 neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the γ-ray opacity of the Universe.

关键词： Gamma ray astronomy Active & peculiar galaxies Axions

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