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BOW TIES in the SKY. I. the ANGULAR STRUCTURE of INVERSE COMPTON GAMMA RAY HALOS in the FERMI SKY

Published version
Peer-reviewed

Type

Article

Change log

Authors

Broderick, AE 
Tiede, P 
Puchwein, E 

Abstract

Extended inverse Compton halos are generally anticipated around extragalactic sources of gamma rays with energies above 100 GeV. These result from inverse Compton scattered cosmic microwave background photons by a population of high-energy electron/positron pairs produced by the annihilation of the high-energy gamma rays on the infrared background. Despite the observed attenuation of the high-energy gamma rays, the halo emission has yet to be directly detected. Here, we demonstrate that in most cases these halos are expected to be highly anisotropic, distributing the up-scattered gamma rays along axes defined either by the radio jets of the sources or oriented perpendicular to a global magnetic field. We present a pedagogical derivation of the angular structure in the inverse Compton halo and provide an analytic formalism that facilitates the generation of mock images. We discuss exploiting this fact for the purpose of detecting gamma-ray halos in a set of companion papers.

Description

Keywords

BL Lacertae objects: general, gamma rays: diffuse background, gamma rays: general, infrared: diffuse background, plasmas, radiation mechanisms: nonthermal

Journal Title

Astrophysical Journal

Conference Name

Journal ISSN

0004-637X
1538-4357

Volume Title

Publisher

American Astronomical Society
Sponsorship
A.E.B. receives financial support from the Perimeter Institute for Theoretical Physics and the Natural Sciences and Engineering Research Council of Canada through a Discovery Grant. Research at Perimeter Institute is supported by the Government of Canada through Industry Canada and by the Province of Ontario through the Ministry of Research and Innovation. C.P. acknowledges support by the European Research Council under ERC-CoG grant CRAGSMAN-646955 and by the Klaus Tschira Foundation. P.C. gratefully acknowledges support from the NASA ATP program through NASA grant NNX13AH43G, and NSF grant AST-1255469. A.L. receives financial support from an Alfred P. Sloan Research Fellowship, NASA ATP Grant NNX14AH35G, and NSF Collaborative Research Grant 411920 and CAREER grant 1455342. E.P. acknowledges support by the Kavli Foundation.