Are pulsar halos rare?
نویسندگان
چکیده
Context. Extended gamma-ray emission, interpreted as halos formed by the inverse-Compton scattering of ambient photons electron-positron pairs, is observed toward a number middle-aged pulsars. The physical origin and actual commonness phenomenon in Galaxy remain unclear. conditions pair confinement seem extreme compared to what can be achieved recent theoretical models. Aims. We searched for scenarios minimizing much possible extent magnitude diffusion suppression J0633+1746 B0656+14, explored implications on local positron flux if they are applied all nearby Methods. used phenomenological static two-zone framework, its predictions with Fermi -LAT HAWC observations two halos, measured AMS-02. Results. While strong three orders at ?100 TeV required data, it find solutions extents small 30 pc both objects. If pulsars develop such their combined including contribution from Geminga would saturate ?100 GeV AMS-02 measurement injection efficiencies that smaller than those inferred canonical more generally values typical younger pulsar wind nebulae. Conversely, positrons other released interstellar medium without any around source, total fits into spectrum same few tens percent pulsars, objects thousand years age power bright nebulae older like B0656+14. Conclusions. It seems simpler assume most do not although evidence supporting this scenario depends properties population uncertain physics driving formation evolution halos. occurrence rate could low ?5?10%, ?0.1?1.0 range thus attributed dozen rapidly releasing pairs medium, over part or J0633+1746, higher energies
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ژورنال
عنوان ژورنال: Astronomy and Astrophysics
سال: 2022
ISSN: ['0004-6361', '1432-0746']
DOI: https://doi.org/10.1051/0004-6361/202243481