Magnetic Field Amplification and Flat Spectrum Radio Quasars

التفاصيل البيبلوغرافية
العنوان: Magnetic Field Amplification and Flat Spectrum Radio Quasars
المؤلفون: Chen, Xuhui, Chatterjee, Ritaban, Zhang, Haocheng, Pohl, Martin, Fossati, Giovanni, Boettcher, Markus, Bailyn, Charles D., Bonning, Erin W., Buxton, Michelle, Coppi, Paolo, Isler, Jedidah, Maraschi, Laura, Urry, Meg
سنة النشر: 2014
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - High Energy Astrophysical Phenomena
الوصف: We perform time-dependent, spatially-resolved simulations of blazar emission to evaluate several flaring scenarios related to magnetic-field amplification and enhanced particle acceleration. The code explicitly accounts for light-travel-time effects and is applied to flares observed in the flat spectrum radio quasar (FSRQ) PKS 0208-512, which show optical/{\gamma}-ray correlation at some times, but orphan optical flares at other times. Changes in both the magnetic field and the particle acceleration efficiency are explored as causes of flares. Generally, external Compton emission appears to describe the available data better than a synchrotron self-Compton scenario, and in particular orphan optical flares are difficult to produce in the SSC framework. X-ray soft-excesses, {\gamma}-ray spectral hardening, and the detections at very high energies of certain FSRQs during flares find natural explanations in the EC scenario with particle acceleration change. Likewise, optical flares with/without {\gamma}-ray counterparts can be explained by different allocations of energy between the magnetization and particle acceleration, which may be related to the orientation of the magnetic field relative to the jet flow. We also calculate the degree of linear polarization and polarization angle as a function of time for a jet with helical magnetic field. Tightening of the magnetic helix immediately downstream of the jet perturbations, where flares occur, can be sufficient to explain the increases in the degree of polarization and a rotation by >= 180 degree of the observed polarization angle, if light-travel-time effects are properly considered.
Comment: 12 pages, 9 figures. Accepted for publication in MNRAS
نوع الوثيقة: Working Paper
DOI: 10.1093/mnras/stu713
URL الوصول: http://arxiv.org/abs/1404.2193
رقم الأكسشن: edsarx.1404.2193
قاعدة البيانات: arXiv