Relativistic Shear Flow Between Electron-Ion and Electron-Positron Plasmas and Astrophysical Applications

We present Particle-in-Cell simulation results of relativistic shear boundary layers between electron-ion and electron-positron plasmas and discuss their potential applications to astrophysics. Specifically, we find in the case of a fast electron-positron spine surrounded by a slow-moving or stationary electron-ion sheath, lepton acceleration proceeds in a highly anisotropic manner due to electromagnetic fields created at the shear interface. While the highest-energy leptons still produce a beaming pattern (as seen in the quasi-stationary frame of the sheath) of order 1/{\Gamma}, where {\Gamma} is the bulk Lorentz factor of the spine, for lower-energy particles, the beaming is much less pronounced. This is in stark contrast to the case of pure electron-ion shear layers, in which anisotropic particle acceleration leads to significantly narrower beaming patterns than 1/{\Gamma} for the highest-energy particles. In either case, shear-layer acceleration is expected to produce strongly angle-dependent lepton (and hence, emanating radiation) spectra, with a significantly harder spectrum in the forward direction than viewed from larger off-axis angles, much beyond the regular Doppler boosting effect from a co-moving isotropic lepton distribution. This may solve the problem of the need for high (and apparently arbitrarily chosen) minimum Lorentz factors of radiating electrons, often plaguing current blazar and GRB jet modeling efforts.

Comments: 29 pages, 10 figures, submitted to ApJ

Similar Publications

The HAWC gamma-ray observatory is a wide field of view and high duty cycle $\gamma$-ray detector investigating the 0.1 - 100 TeV energy range. It has detected supermassive black holes in the near Universe, and is seeking to detect black hole related objects like gamma-ray bursts, Galactic binary systems, primordial black holes and gravitational wave mergers. Read More


The Jeans analysis is studied in the first post-Newtonian limit. In other words, the relativistic effects on the local gravitational instability are considered for systems where characteristic velocity of the system and corresponding gravitational field are higher than what permitted in Newtonian limit. The dispersion relation for propagation of small perturbations is found in the post-Newtonian approximation using two different techniques. Read More


2017Mar
Authors: M. L. Ahnen1, S. Ansoldi2, L. A. Antonelli3, C. Arcaro4, A. Babić5, B. Banerjee6, P. Bangale7, U. Barres de Almeida8, J. A. Barrio9, J. Becerra González10, W. Bednarek11, E. Bernardini12, A. Berti13, B. Biasuzzi14, A. Biland15, O. Blanch16, S. Bonnefoy17, G. Bonnoli18, F. Borracci19, T. Bretz20, R. Carosi21, A. Carosi22, A. Chatterjee23, P. Colin24, E. Colombo25, J. L. Contreras26, J. Cortina27, S. Covino28, P. Cumani29, P. Da Vela30, F. Dazzi31, A. De Angelis32, B. De Lotto33, E. de Oña Wilhelmi34, F. Di Pierro35, M. Doert36, A. Domínguez37, D. Dominis Prester38, D. Dorner39, M. Doro40, S. Einecke41, D. Eisenacher Glawion42, D. Elsaesser43, M. Engelkemeier44, V. Fallah Ramazani45, A. Fernández-Barral46, D. Fidalgo47, M. V. Fonseca48, L. Font49, C. Fruck50, D. Galindo51, R. J. García López52, M. Garczarczyk53, M. Gaug54, P. Giammaria55, N. Godinović56, D. Gora57, D. Guberman58, D. Hadasch59, A. Hahn60, T. Hassan61, M. Hayashida62, J. Herrera63, J. Hose64, D. Hrupec65, G. Hughes66, W. Idec67, K. Ishio68, K. Kodani69, Y. Konno70, H. Kubo71, J. Kushida72, D. Lelas73, E. Lindfors74, S. Lombardi75, F. Longo76, M. López77, P. Majumdar78, M. Makariev79, K. Mallot80, G. Maneva81, M. Manganaro82, K. Mannheim83, L. Maraschi84, M. Mariotti85, M. Martínez86, D. Mazin87, U. Menzel88, R. Mirzoyan89, A. Moralejo90, E. Moretti91, D. Nakajima92, V. Neustroev93, A. Niedzwiecki94, M. Nievas Rosillo95, K. Nilsson96, K. Nishijima97, K. Noda98, L. Nogués99, M. Nöthe100, S. Paiano101, J. Palacio102, D. Paneque103, R. Paoletti104, J. M. Paredes105, X. Paredes-Fortuny106, G. Pedaletti107, M. Peresano108, L. Perri109, M. Persic110, J. Poutanen111, P. G. Prada Moroni112, E. Prandini113, I. Puljak114, J. R. Garcia115, I. Reichardt116, W. Rhode117, M. Ribó118, J. Rico119, T. Saito120, K. Satalecka121, S. Schroeder122, T. Schweizer123, S. N. Shore124, A. Sillanpää125, J. Sitarek126, I. Šnidarić127, D. Sobczynska128, A. Stamerra129, M. Strzys130, T. Surić131, L. Takalo132, F. Tavecchio133, P. Temnikov134, T. Terzić135, D. Tescaro136, M. Teshima137, D. F. Torres138, N. Torres-Albà139, T. Toyama140, A. Treves141, G. Vanzo142, M. Vazquez Acosta143, I. Vovk144, J. E. Ward145, M. Will146, M. H. Wu147, F. Krauß148, R. Schulz149, M. Kadler150, J. Wilms151, E. Ros152, U. Bach153, T. Beuchert154, M. Langejahn155, C. Wendel156, N. Gehrels157, W. H. Baumgartner158, C. B. Markwardt159, C. Müller160, V. Grinberg161, T. Hovatta162, J. Magill163
Affiliations: 1ETH Zurich, Institute for Particle Physics, Zurich, Switzerland, 2Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 3INAF - National Institute for Astrophysics, Roma, Italy, 4Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 5Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 6Saha Institute of Nuclear Physics, HBNI, Kolkata, India, 7Max-Planck-Institut für Physik, München, Germany, 8Max-Planck-Institut für Physik, München, Germany, 9Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 10Instituto de Astrofisica de Canarias, La Laguna, 11Division of Astrophysics, University of Lodz, Lodz, Poland, 12Deutsches Elektronen-Synchrotron, 13Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 14Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 15ETH Zurich, Institute for Particle Physics, Zurich, Switzerland, 16Institut de Fisica d'Altes Energies, 17Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 18Dipartimento di Fisica, Università di Siena and INFN sez. di Pisa, Siena, Italy, 19Max-Planck-Institut für Physik, München, Germany, 20Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 21Dipartimento di Fisica, Università di Siena and INFN sez. di Pisa, Siena, Italy, 22INAF - National Institute for Astrophysics, Roma, Italy, 23Saha Institute of Nuclear Physics, HBNI, Kolkata, India, 24Max-Planck-Institut für Physik, München, Germany, 25Instituto de Astrofisica de Canarias, La Laguna, 26Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 27Institut de Fisica d'Altes Energies, 28INAF - National Institute for Astrophysics, Roma, Italy, 29Institut de Fisica d'Altes Energies, 30Dipartimento di Fisica, Università di Siena and INFN sez. di Pisa, Siena, Italy, 31Max-Planck-Institut für Physik, München, Germany, 32Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 33Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 34Institut de Ciencies de l'Espai, 35INAF - National Institute for Astrophysics, Roma, Italy, 36Technische Universität Dortmund, Dortmund, Germany, 37Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 38Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 39Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 40Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 41Technische Universität Dortmund, Dortmund, Germany, 42Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 43Technische Universität Dortmund, Dortmund, Germany, 44Technische Universität Dortmund, Dortmund, Germany, 45Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 46Institut de Fisica d'Altes Energies, 47Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 48Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 49Universitat Autònoma de Barcelona, Barcelona, Spain, 50Max-Planck-Institut für Physik, München, Germany, 51Universitat de Barcelona, Barcelona, Spain, 52Instituto de Astrofisica de Canarias, La Laguna, 53Deutsches Elektronen-Synchrotron, 54Universitat Autònoma de Barcelona, Barcelona, Spain, 55INAF - National Institute for Astrophysics, Roma, Italy, 56Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 57Deutsches Elektronen-Synchrotron, 58Institut de Fisica d'Altes Energies, 59Japanese MAGIC Consortium, Kyoto, Japan, 60Max-Planck-Institut für Physik, München, Germany, 61Institut de Fisica d'Altes Energies, 62Japanese MAGIC Consortium, Kyoto, Japan, 63Instituto de Astrofisica de Canarias, La Laguna, 64Max-Planck-Institut für Physik, München, Germany, 65Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 66ETH Zurich, Institute for Particle Physics, Zurich, Switzerland, 67Division of Astrophysics, University of Lodz, Lodz, Poland, 68Max-Planck-Institut für Physik, München, Germany, 69Japanese MAGIC Consortium, Kyoto, Japan, 70Japanese MAGIC Consortium, Kyoto, Japan, 71Japanese MAGIC Consortium, Kyoto, Japan, 72Japanese MAGIC Consortium, Kyoto, Japan, 73Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 74Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 75INAF - National Institute for Astrophysics, Roma, Italy, 76Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 77Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 78Saha Institute of Nuclear Physics, HBNI, Kolkata, India, 79Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria, 80Deutsches Elektronen-Synchrotron, 81Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria, 82Instituto de Astrofisica de Canarias, La Laguna, 83Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 84INAF - National Institute for Astrophysics, Roma, Italy, 85Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 86Institut de Fisica d'Altes Energies, 87Max-Planck-Institut für Physik, München, Germany, 88Max-Planck-Institut für Physik, München, Germany, 89Max-Planck-Institut für Physik, München, Germany, 90Institut de Fisica d'Altes Energies, 91Max-Planck-Institut für Physik, München, Germany, 92Japanese MAGIC Consortium, Kyoto, Japan, 93Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 94Division of Astrophysics, University of Lodz, Lodz, Poland, 95Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 96Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 97Japanese MAGIC Consortium, Kyoto, Japan, 98Max-Planck-Institut für Physik, München, Germany, 99Institut de Fisica d'Altes Energies, 100Technische Universität Dortmund, Dortmund, Germany, 101Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 102Institut de Fisica d'Altes Energies, 103Max-Planck-Institut für Physik, München, Germany, 104Dipartimento di Fisica, Università di Siena and INFN sez. di Pisa, Siena, Italy, 105Universitat de Barcelona, Barcelona, Spain, 106Universitat de Barcelona, Barcelona, Spain, 107Deutsches Elektronen-Synchrotron, 108Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 109INAF - National Institute for Astrophysics, Roma, Italy, 110Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 111Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 112Universita di Pisa, and INFN Pisa, Pisa, Italy, 113Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 114Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 115Max-Planck-Institut für Physik, München, Germany, 116Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 117Technische Universität Dortmund, Dortmund, Germany, 118Universitat de Barcelona, Barcelona, Spain, 119Institut de Fisica d'Altes Energies, 120Japanese MAGIC Consortium, Kyoto, Japan, 121Deutsches Elektronen-Synchrotron, 122Technische Universität Dortmund, Dortmund, Germany, 123Max-Planck-Institut für Physik, München, Germany, 124Universita di Pisa, and INFN Pisa, Pisa, Italy, 125Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 126Division of Astrophysics, University of Lodz, Lodz, Poland, 127Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 128Division of Astrophysics, University of Lodz, Lodz, Poland, 129INAF - National Institute for Astrophysics, Roma, Italy, 130Max-Planck-Institut für Physik, München, Germany, 131Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 132Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 133INAF - National Institute for Astrophysics, Roma, Italy, 134Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria, 135Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 136Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 137Max-Planck-Institut für Physik, München, Germany, 138ICREA and Institut de Ciencies de l'Espai, 139Universitat de Barcelona, Barcelona, Spain, 140Max-Planck-Institut für Physik, München, Germany, 141Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 142Instituto de Astrofisica de Canarias, La Laguna, 143Instituto de Astrofisica de Canarias, La Laguna, 144Max-Planck-Institut für Physik, München, Germany, 145Institut de Fisica d'Altes Energies, 146Instituto de Astrofisica de Canarias, La Laguna, 147Institut de Ciencies de l'Espai, 148GRAPPA and Anton Pannekoek Institute for Astronomy, University of Amsterdam, The Netherlands, 149ASTRON, the Netherlands Institute for Radio Astronomy, Dwingeloo, Netherlands, 150Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 151Dr. Remeis Sternwarte and ECAP, Universität Erlangen-Nürnberg, Bamberg, Germany, 152Max-Planck-Institut für Radioastronomie, Bonn, Germany, 153Max-Planck-Institut für Radioastronomie, Bonn, Germany, 154Dr. Remeis Sternwarte and ECAP, Universität Erlangen-Nürnberg, Bamberg, Germany, 155Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 156Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 157NASA, Goddard Space Flight Center, Greenbelt, USA, 158NASA, Goddard Space Flight Center, Greenbelt, USA, 159NASA, Goddard Space Flight Center, Greenbelt, USA, 160Department of Astrophysics/IMAPP, Radboud University Nijmegen, Nijmegen, the Netherlands, 161Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, USA, 162Aalto University Metsähovi Radio Observatory, Kylmälä, Finland, 163Department of Physics and Department of Astronomy, University of Maryland, College Park, USA)

The extragalactic VHE gamma-ray sky is rich in blazars. These are jetted active galactic nuclei viewed at a small angle to the line-of-sight. Only a handful of objects viewed at a larger angle are known so far to emit above 100 GeV. Read More


We present MUSE observations of galaxy NGC 7469 from its Science Verification to show how powerful is the combination of high-resolution wide-field integral field spectroscopy with both photometric and spectroscopic observations of supernova (SN) explosions. Using STARLIGHT and HIIexplorer, we selected all Hii regions of the galaxy and produced 2- dimensional maps of the H{\alpha} equivalent width, average luminosity-weighted stellar age, and oxygen abundance. We measured deprojected galactocentric distances for all Hii regions, and radial gradients for all above-mentioned parameters. Read More


Solar $\gamma$ ray events measured near Earth can last several hours during so-called Long Duration Gamma Ray Flares (LDGRFs). LDGRFs suggest that a particle-acceleration mechanism operates over many hours to produce energetic protons that stream continually towards the solar surface. Coronal shocks, driven by the expansion of Coronal Mass Ejections (CMEs), could be the source of these energetic particles. Read More


2017Mar
Affiliations: 1School of Physics and Astronomy, Monash University, 2School of Physics and Astronomy, Monash University, 3X-ray Astrophysics Laboratory, Astrophysics Science Division, NASA/GSFC

We present a sample of observations of thermonuclear (type-I) X-ray bursts, selected for comparison with numerical models. Provided are examples of four distinct cases of thermonuclear ignition: He-ignition in mixed H/He fuel (case 1 of Fujimoto et al. 1981); He-ignition in pure He fuel, following exhaustion of accreted H by steady burning (case 2); ignition in (almost) pure He accumulated from an evolved donor in an ultracompact system; and an example of a superburst, thought to arise from ignition of a layer of carbon fuel produced as a by-product of more frequent bursts. Read More


Supermassive primordial stars are now suspected to be the progenitors of the most massive quasars at z~6. Previous studies of such stars were either unable to resolve hydrodynamical timescales or considered stars in isolation, not in the extreme accretion flows in which they actually form. Therefore, they could not self-consistently predict their final masses at collapse, or those of the resulting supermassive black hole seeds, but rather invoked comparison to simple polytropic models. Read More


2017Mar
Affiliations: 1CIERA/Northwestern, 2Caltech, 3UW e-Science Institute, 4Oskar Klein Centre - Physics, 5Weizmann Institute, 6IPAC, 7Caltech, 8IPAC, 9LBNL, 10Dark Cosmology Centre, 11Oskar Klein Centre - Physics, 12SDSU, 13JPL, 14Oskar Klein Centre - Astronomy, 15Oskar Klein Centre - Astronomy, 16Caltech

Modern wide-field, optical time-domain surveys must solve a basic optimization problem: maximize the number of transient discoveries or minimize the follow-up needed for the new discoveries. Here, we describe the Color Me Intrigued experiment, the first from the intermediate Palomar Transient Factory (iPTF) to search for transients simultaneously in the $g_\mathrm{PTF}$- and $R_\mathrm{PTF}$-bands. During the course of this experiment we discovered iPTF$\,$16fnm, a new member of the 02cx-like subclass of type Ia supernovae (SNe). Read More


Recently, the author proposed an alternative vector theory of gravity. To the best of our knowledge, vector gravity also passes available tests of gravity, and, in addition, predicts the correct value of the cosmological constant without free parameters. It is important to find a new feasible test which can distinguish between vector gravity and general relativity and determine whether gravity has a vector or a tensor origin. Read More


Cosmic Rays (CR) are high energy particles which come from the universe. When one of those particles enters to the atmosphere of the earth it produces an air shower, conformed by secondary particles in which the initial energy is distributed. The Pierre Auger Observatory, located in Argentina, is dedicated to the study of those events. Read More