Probing Nearby CR Accelerators and ISM Turbulence with Milagro Hot Spots

POSTER

Abstract

Acceleration of cosmic rays (CR) in supernova remnant shocks should result in an almost isotropic CR spectrum. Yet the MILAGRO TeV observatory discovered a sharp $\sim$10 deg arrival anisotropy. We suggest a mechanism for producing a narrow CR beam which operates en route to the observer. The key assumption is that CRs are scattered by a strongly anisotropic Alfven wave spectrum formed by the turbulent cascade across the local field direction. The strongest pitch-angle scattering occurs for particles moving almost precisely along the field line. The enhanced scattering results in a weak but narrow particle excess. The width, the fractional excess and the maximum momentum of the beam are calculated from a systematic transport theory depending on a single scale L which can be associated with the longest Alfven wave, efficiently scattering the beam. The best match to all the three characteristics of the beam is achieved at L$\sim$1 pc. The distance to a possible source of the beam is estimated to be within a few 100pc. Possible approaches to determination of the scale L from the characteristics of the source are discussed. Alternative scenarios of drawing the beam from the galactic CR background are considered. The beam related large scale anisotropic CR component is found to be energy independent which is also consistent with the observations.

Authors

  • Luke Drury

    Dublin Institute for Advanced Studies

  • Mikhail Malkov

    UCSD

  • Patrick Diamond

    UCSD

  • Antony Valentini

    CITA, MIT, Caltech/JPL, Academia Sinica, Dong Hwa Univ., Soochow Univ., Nanticoke High School, UT, Maverick Systems Corp., RIS Corp., LSU, Shimadzu Corp., UNIRIB, ORAU/ORISE, Physics Division, Oak Ridge National Laboratory, Oak Ridge Associated Universities, Los Alamos National Laboratory, University of South Dakota, RIKEN BNL Research Center, University of Wisconsin-Milwaukee, Brown University, University of Maryland, Jet Propulsion Laboratory - California Institute of Technology, Center for Relativistic Astrophysics, Georgia Tech, University of Rochester, University of Idaho, Texas A\&M University, Universit\'e Paris Diderot-Paris 7, Washington University in St. Louis, Harvard-Smithsonian Center for Astrophysics, University of California, Berkeley, Massachusetts Institute of Technology, Rockwell Collins Inc., Northwestern University, N IST, Indiana Unviersity, Harvard University, University of Notre Dame, Fachbereich Theoretische Physik, Institut fur Physik, Karl-Franzens-Universitat Graz, Austria, Instituto de Estructura de la Materia, CSIC, Spain, Physics Department, University of Wisconsin-Barron, Orion Foundation, Physics Dept, University of West Florida, Pensacola, Florida, 32514, TUNL, Duke University, James Madison University, University of New Mexico, Photonics CoE, Idaho State University, Pocatello, ID 83209, Los Alamos National Laboratory, Los Alamos, NM 87545, Argonne National Laboratory, University of Washington, National Institute of Standards and Technology, National Institute of Standards and Technology (and West Virginia University), NRAO, University of Florida, LLNL / NPS, LLNL, UC Berkeley, LLNL/NPS, Univerity of Washington, CNRS-IN2P3, Marseille, FR, CERN and King's College, London UK, Brookhaven National Laboratory, ICTP, Trieste, IT, Fermi National Accelerator Laboratory, University of Wisconsin Milwaukee, Princeton University, North Carolina Central U. (NCCU), Triangle Universities Nuclear Laboratory (TUNL), University of California, Riverside, NSCL/MSU, Triangle Universities Nuclear Laboratory, Duke University, University of North Carolina, Duke University, University of North Carolina at Chapel Hill, Triangle Universities Nuclear Laboratory, KVI Groningen, APS Director of Public Affairs, Perimeter Institute, Caltech, Rutgers, U. Tenn., ORNL, Stanford School of Medicine, Radiation Oncology and Molecular Imaging Program, Stanford Applied Physics Department, Stanford School of Medicine, Radiation Oncology, Boston University, BNL, Rutgers University, Purdue University, Penn. State University, UCSD, Lawrence Livermore National Laboratory, University of Richmond, University of Massachusetts-Lowell, Mississippi State University, University of Tennessee, Argonne National Lab, Florida State University, US Naval Academy, ANL, Univ. of Maryland, Univ. of Massachusetts (Lowell), Univ. of Tennessee, Univ. of Manchester, UK, NBI, Danmark, Mississippi State Univ., Physics Division, Argonne National Laboratory, Argonne, IL 60439, Mississippi State University, Mississippi State, MS 39762, UGC-DAE Consortium for Science Research, Kolkata, India, Department of Physics, University of Notre Dame, Notre Dame, IN 46556, San Jose State University, Pacific Northwest National Laboratory, University of Chicago, Fermilab, Program Director, US LHC Accelerator Research Program (LARP), Montana State University, Department of Astrophysical Sciences, Princeton University, School of Mathematics, University of Southampton, CCT, Louisiana State University, CSIC-IEEC Barcelona, TAPIR, California Institute of Technology, University of Texas at Brownsville, Royal Military College of Canada, California State University, Sacramento, Norfolk State University, Oak Ridge National Laboratory, Utah State University, Executive Producer \& Co-Creator of The Big Bang Theory, University of California, Los Angeles, Cyclotron Institute, Texas A\&M University, Hope College, NSCL, Augustana College, Clemson University