کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1770999 | 1020717 | 2011 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The production of ultra high energy cosmic rays during the early epochs of radio-loud AGN
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موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
نجوم و فیزیک نجومی
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چکیده انگلیسی
Powerful radio-loud active galactic nuclei (AGN) with large Mpc-scale jets have been theoretically motivated as emitters of high-energy cosmic rays. Recent radio observations have established a populous class of young radio-loud galaxies with compact (<1Â kpc) symmetric jets that are morphologically similar to large-scale AGNs. We show that these compact AGNs, so-called compact symmetric objects (CSOs), can accelerate protons up to 1020Â eV at their hot spots via a Fermi type mechanism on the assumption of efficient acceleration. The required magnetic field strengths are comparable to those derived from the minimum energy condition. We further show that the accelerated protons can escape through the photon fields of the cocoon without significant energy loss. However, the local number density of powerful CSOs is insufficient for CSOs to power the entire observed flux of ultra-high-energy cosmic rays, providing maximally only a few percent. A heavy composition of UHECRs allows more CSOs to accelerate particles to UHECR energies, but escaping the cocoon is difficult. We comment on a method that may test CSOs as UHECR sources.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Astroparticle Physics - Volume 34, Issue 10, May 2011, Pages 749-754
Journal: Astroparticle Physics - Volume 34, Issue 10, May 2011, Pages 749-754
نویسندگان
Hajime Takami, Shunsaku Horiuchi,