کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1845624 1528078 2014 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Fermi bubbles as a source of cosmic rays above 1015 eV
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک هسته ای و انرژی بالا
پیش نمایش صفحه اول مقاله
Fermi bubbles as a source of cosmic rays above 1015 eV
چکیده انگلیسی

Fermi bubbles are giant gamma-ray structures extended north and south of the Galactic center with characteristic sizes of order of 10 kpc recently discovered by Fermi Large Area Telescope. Good correlation between radio and gamma-ray emission in the region covered by Fermi bubbles implies the presence of high-energy electrons in this region. Since it is relatively difficult for relativistic electrons of this energy to travel all the way from the Galactic sources toward Fermi bubbles one can assume that they accelerated in-situ. The corresponding acceleration mechanism should also affect the distribution of the relativistic protons in the Galaxy. Since protons have much larger lifetimes the effect may even be observed near the Earth. In our model we suggest that Fermi bubbles are created by acceleration of electrons on series of shocks born due to periodic star accretions by supermassive black hole Sgr A*. We propose that hadronic CR within the “knee” of the observed CR spectrum are produced by Galactic supernova remnants distributed in the Galactic disk. Reacceleration of these particles in the Fermi Bubble produces CRs beyond the knee. This model provides a natural explanation of the observed CR flux, spectral indexes, and matching of spectra at the knee.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Physics B - Proceedings Supplements - Volumes 256–257, November–December 2014, Pages 179-185