Measurement of the Cosmic Ray<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo>+</mml:mo><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope

Abdo, A. A.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, Luca; Ballet, J.; Barbiellini, G.; Bastieri, D.; Battelino, Milan; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bogaert, G.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, Pascal; Burnett, T. H.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Carlson, P.; Casandjian, J. M.; Cecchi, C.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L.; Conrad, J.; Cutini, S.; Dermer, C. D.; Angelis, A. De; Palma, F. de; Digel, S. W.; Bernardo, Giuseppe Di; Silva, E. do Couto e; Drell, P. S.; Dubois, R.; Dumora, D.; Edmonds, Y.; Farnier, C.; Favuzzi, C.; Focke, W. B.; Frailis, M.; Fukazawa, Yasushi; Funk, S.; Fusco, P.; Gaggero, Daniele; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Grasso, Dario; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Harding, A. K.; Hartman, R. C.; Hayashida, M.; Hays, E.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, R. P.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocevski, D.; Kuehn, F.; Kuss, M.; Landé, J.; Latronico, L.; Lemoine‐Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G.; Makeev, A.; Massai, M.M.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Моисеев, А. А.; Monte, C.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, Masanori; Paneque, D.; Panetta, J.; Parent, D.; Pelassa, V.; Pepé, M.; Pesce-Rollins, M.; Piron, F.; Pohl, M.; Porter, T. A.; Profumo, Stefano; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reposeur, T.; Ritz, S.; Rochester, Lynn; Rodriguez, A. Y.; Romani, Roger W.; Roth, M.; Ryde, F.; Sadrozinski, H. F-W.; Sánchez, David; Sander, A.; Parkinson, P. M. Saz; Scargle, J. D.; Schalk, T.; Sellerholm, A.; Sgrò, C.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Starck, Jean-Luc; Stephens, T. E.; Strickman, M. S.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, Takaaki; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T.; Etten, A. van; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wallace, E.; Wang, P.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Ziegler, M.

doi:10.1103/physrevlett.102.181101

Cited by 820 publications

(502 citation statements)

References 21 publications

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“…Decay Over the last couple of years, a lot of attention has been given to the decaying DM as a possible explanation of the flux excesses of high-energy positrons and electrons measured by PAMELA [50], Fermi -LAT [51], H.E.S.S [52] and AMS-02 [53]. The needed DM particle lifetime in such a case, τ χ > 10 26 s, is much longer than the age of the Universe, so that the slow decay does not significantly reduce the overall DM abundance and, therefore, there is no contradiction with the astrophysical and cosmological observations.…”

Section: Secondary Photons From Final State Standard Model Particlesmentioning

confidence: 99%

Optimized Dark Matter Searches in Deep Observations of Segue 1 with MAGIC

Aleksić

2016

Springer Theses

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Abstract. We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ∼500 GeV dark matter particle annihilating into τ + τ − , and is of order σ ann v ≃ 1.2×10 −24 cm 3 s −1 -a factor ∼40 above the σ ann v thermal value.

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Section: Secondary Photons From Final State Standard Model Particlesmentioning

confidence: 99%

Optimized Dark Matter Searches in Deep Observations of Segue 1 with MAGIC

Aleksić

2016

Springer Theses

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“…Also shown is the (e + + e − ) spectrum for the benchmark model (red curve). The FERMI (e + + e − ) data [5] is also shown. Figure 8: e + /(e + + e − ) spectra for all 524 astrophysical models with no SUSY contributions (grey curves).…”

Section: Jhep01(2011)064mentioning

confidence: 99%

“…The PAMELA collaboration observes [4] a steep rise in the positron fraction (the ratio of positrons over the sum of electrons plus positrons) at energies between 10 and 100 GeV. The Fermi Gamma Ray Space Telescope (FERMI) reports [5] a slightly stiffer electron spectrum than expected, but with no dramatic features. These are countered by observations of the anti-proton fraction (ratio ofp to p) by PAMELA [6] and various gamma ray measurements by FERMI ( [7][8][9];preliminary results for a larger range of energies were presented in [10]) which reveal no unexpected characteristics.…”

Section: Introductionmentioning

confidence: 99%

Cosmic ray anomalies from the MSSM?

Cotta

Conley

Gainer

et al. 2011

J. High Energ. Phys.

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Abstract:The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total (e + + e − ) flux and from PAMELA itself on thep/p ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional mSUGRA version of Supersymmetry even if boosts as large as 10 3−4 are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the MSSM with a corresponding scan over astrophysical parameters that describe the propagation of CR. We then ascertain whether or not a good fit to this CR data can be obtained with relatively small boost factors while simultaneously satisfying the additional constraints arising from gamma ray data. We find that a specific subclass of MSSM models where the LSP is mostly pure bino and annihilates almost exclusively into τ pairs comes very close to satisfying these requirements. The lightestτ in this set of models is found to be relatively close in mass to the LSP and is in some cases the nLSP. These models lead to a significant improvement in the overall fit to the data by an amount ∆χ 2 ∼ 1/dof in comparison to the best fit without Supersymmetry while employing boosts ∼ 100. The implications of these models for future experiments are discussed.

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“…Electrons produced in local SNRs are expected to fill out the electron spectrum above 100 GeV. In this picture the fraction of positrons in the cosmic ray lepton spectrum should decrease with increasing energy, in contradiction to results from ATIC [6], PAMELA [18], Fermi LAT [19] and AMS [4], which show that the positron fraction in fact increases with energy. While this effect could be produced by WIMP dark matter annihilation, the anomalous positron fraction can also be explained by nearby astrophysical sources, most notably pulsars and PWNe.…”

Section: Pulsar Wind Nebulae and The Positron Excessmentioning

confidence: 80%

Pulsar Wind Nebulae and Cosmic Rays: A Bedtime Story

Weinstein¹

2014

Nuclear Physics B - Proceedings Supplements

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The role pulsar wind nebulae play in producing our locally observed cosmic ray spectrum remains murky, yet intriguing. Pulsar wind nebulae are born and evolve in conjunction with SNRs, which are favored sites of Galactic cosmic ray acceleration. As a result they frequently complicate interpretation of the gamma-ray emission seen from SNRs. However, pulsar wind nebulae may also contribute directly to the local cosmic ray spectrum, particularly the leptonic component. This paper reviews the current thinking on pulsar wind nebulae and their connection to cosmic ray production from an observational perspective. It also considers how both future technologies and new ways of analyzing existing data can help us to better address the relevant theoretical questions. A number of key points will be illustrated with recent results from the VHE (E > 100 GeV) gamma-ray observatory VERITAS. Keywords: IntroductionThe discovery of cosmic rays in the early twentieth century [1, 2] inaugurated a decades-long, serialized mystery story that has yet to be completed. At the heart of the mystery lies a set of of simple questions. What particles appear in the cosmic ray spectrum that we see from Earth? Where do these particles originate? How are they accelerated? In recent decades direct cosmic ray observations have brought us a wealth of information on the cosmic ray spectrum and its composition, clues to the types of environments in which cosmic rays are born. The interaction of these particles with interstellar magnetic fields, however, prevents them from being traced back to their point of origin.In order to pursue the other half of this mystery-the nature of cosmic ray accelerators-we must use the secondary photon radiation produced in these cosmic ray nurseries. These high-energy (300 MeV -100 GeV) and very high-energy (VHE; E > 100 GeV) gamma rays are not deflected by interstellar magnetic fields and can be used to map cosmic ray populations in and near their parent accelerators. The different processes by which relativistic cosmic ray electrons, protons, and heavier nuclei produce high-energy gamma rays leave characteristic imprints on the gamma-ray energy spectrum of particular astrophysical accelerators. These features may be used to constrain the composition and energy spectrum of accelerated particle populations.The local cosmic ray spectrum is known to be a mix of protons and heavier nuclei, with a smaller admixture of leptons. A mix of astrophysical accelerators within and outside our Galaxy is believed to contribute, including shocks arising in supernova remnants (SNRs), shocks formed by interacting high-velocity winds from massive stars [3], pulsars, and active galactic nuclei (AGN). We focus here on a single subplot of a much larger story-the role played by pulsar wind nebulae (PWNe) in our quest to understand the Galactic cosmic ray spectrum. Dramatis PersonaeNo single gamma-ray observatory provides a complete picture of the gamma-ray sky at all energies and spatial scales. The Fermi Gamma-ray Space Telescope (...

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Measurement of the Cosmic Raye++e−Spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope

Cited by 820 publications

References 21 publications

Optimized Dark Matter Searches in Deep Observations of Segue 1 with MAGIC

Optimized Dark Matter Searches in Deep Observations of Segue 1 with MAGIC

Cosmic ray anomalies from the MSSM?

Pulsar Wind Nebulae and Cosmic Rays: A Bedtime Story

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