Abstract
Pulsars, or more generally rotation powered neutron stars, are excellent factories of antimatter in the Galaxy, in the form of pairs of electrons and positrons. Electrons are initially extracted from the surface of the star by the intense rotation induced electric fields and later transformed into electron-positron pairs through electromagnetic cascading. Observations of Pulsar Wind Nebulae (PWNe) show that cascades in the pulsar magnetosphere must ensure pair multiplicities of order 104 -105. These pairs finally end up as part of the relativistic magnetized wind emanating from the pulsar. The wind is slowed down, from its highly relativistic bulk motion, at a termination shock, which represents the reverse shock due to its interaction with the surrounding ejecta of the progenitor supernova. At the (relativistic) termination shock, acceleration of the pairs occurs, as part of the dissipation process, so that the cold wind is transformed into a plasma of relativistic non-thermal particles, plus a potential thermal component, which however has never been observed. As long as the pulsar wind is embedded in the supernova remnant these pairs are forced to escavate a bubble and lose energy adiabatically (because of the expansion) and radiatively (because of magnetic and radiation fields).We discuss here the observational constraints on the energy and number content of such pairs and discuss the scenarios that may allow for the pairs to escape in the interstellar medium and possibly contribute to the positron excess that has recently been detected by the PAMELA satellite. Special attention is dedicated to the case of nebulae surrounding high speed pulsars, observationally classified as Pulsar Bow Shock Nebulae. The pairs produced in these objects may be effectively carried out of the Supernova Remnant and released in the Interstellar Medium. As a result, Bow Shock Pulsar Wind Nebulae might be the main contributors to the positron excess in the Galaxy.
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References
Ahn, H.S., et al. (CREAM Coll.) 2008, Astrop. Phys., 30, 133
Aliu, E., et al. 2008, Science, 322, 1221
Abdo, A. A., et al. 2010, ApJS, 187, 460
Abdo, A., et al. (Fermi Coll.) 2009, PRL, 102, 181101
Adriani, O., et al. (PAMELA Coll.) 2009, Nature, 458, 607
Adriani, O., et al. (PAMELA Coll.) 2009, PRL, 102, 051101
Amato, E., & Arons, J. 2006, ApJ, 653, 325
Arons, L. 2009, ”Pulsar Emission: Where to Go”, Astrophysics and Space Science Library, vol. 357, pag. 373, Eds. W. Becker
Arzoumanian, Z., Chernoff, D. F., Cordes, J. M. 2002, ApJ, 568, 289
Blasi, P. 2009, PRL, 103, 1104
Blasi, P., Amato, E. 2010, in preparation
Blasi, P., Serpico, P. 2009, PRL, 103, 1103
Blasi, P., Vietri, M. 2005, ApJ, 626, 877
Bucciantini, N., Blondin, J. M., Del Zanna, L., & Amato, E. 2003, A&A, 405, 617
Bucciantini, N.,Amato, E., & Del Zanna, L. 2005a, A&A, 434, 189
Bucciantini, N.,Arons, J., & Amato, E. 2010, astro-ph/1005.1831
B¨usching, I., de Jager, O.C., Potgieter, M.S., Venter, C. 2008, ApJ678, 39
Caprioli, D., Amato, E., Blasi, P. 2010, Astrop. Phys., 33, 160
Cholis, I., et al., arXiv:0809.1683
Cirelli, M., and Strumia, A., arXiv:0808.3867
Coroniti, F.V. 1990, ApJ, 349, 538
Del Zanna, L., Amato, E., & Bucciantini, N. 2004, A&A, 421, 1063
Del Zanna, L., Volpi, D., Amato, E., & Bucciantini, N. 2006, A&A, 453, 621
Ferriere, K.M. 2001, Rev. Mod. Phys., 73, 1031
Gaensler, B. M., & Slane, P. O. 2006, ARA&A, 44, 17
Gaensler, B. M., van der Swaluw, E., Kaspi, V. M., et al. 2004, ApJ, 616, 383
Grajek, P., Kane, G., Phalen, D.J., Pierce, A., Watson, S., arXiv:0807.1508.
Grasso, D., et al. (Fermi Coll.), 2009, Astrop. Phys., 32, 140
Hooper, D., Blasi, P., Serpico, P. 2009, JCAP, 1, 25
Hoshino, M., Arons, J., Gallant, Y. A., Langdon, A. B. 1992, ApJ, 390, 454
Kirk, J.G., Lyubarsky, Y., Petri, J. 2009, ”The theory of Pulsar Winds and Nebulae”, Astrophysics and Space Science Library, vol. 357, pag. 421, Ed. W. Becker
Komissarov, S. S., & Lyubarsky, Y. E. 2004, MNRAS, 349, 779
Livingstone, M. A., Kaspi, V. M., Gavriil, F. P.; Manchester, R. N. 2005, ApJ, 619, 1046
Livingstone, M. A., Kaspi, V. M., Gavriil, F. P. 2005, ApJ, 633, 1095
Lyubarsky, Y., Kirk, J. G. 2001, ApJ, 547, 437
Lyubarsky, Y., Liverts, M. 2008, ApJ, 682, 1436
Lyne, A. G., Pritchard, R. S., Graham-Smith, F. 1993, MNRASLetters, 265, 1003
Lyne, A. G., Pritchard, R. S., Graham-Smith, F., Camilo, F. 1996, Nature, 381, 497
Ng, C.-Y., Gaensler, B.M., Chatterjee, S., Johnston, S. 2010, ApJ, 712, 596
Shaviv, N.J., Nakar, E., Piran, T. 2009, PRL, 103, 1302
Sironi, L., Spitkovsky, A. 2009, ApJ, 698, 1523
Stecker, F.W., Baring, M.G., Summerlin, E.J. 2008, ApJ, 667, 29
Syrovat-skii, S.I. 1959, Soviet Astronomy, 3, 22
van der Swaluw, E., Achterberg, A., Gallant, Y. A., & T´oth, G. 2001, A&A, 380, 309
Volpi, D., Del Zanna, L., Amato, E., & Bucciantini, N. 2008, A&A, 485, 337
Yusef-Zadeh, F., Gaensler, B. M. 2005, Advances in Space Research, 35, 1129
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Blasi, P., Amato, E. (2011). Positrons from pulsar winds. In: Torres, D., Rea, N. (eds) High-Energy Emission from Pulsars and their Systems. Astrophysics and Space Science Proceedings. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-17251-9_50
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DOI: https://doi.org/10.1007/978-3-642-17251-9_50
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