Polarized synchrotron emission from the equatorial current sheet in gamma-ray pulsars

التفاصيل البيبلوغرافية
العنوان: Polarized synchrotron emission from the equatorial current sheet in gamma-ray pulsars
المؤلفون: Benoît Cerutti, Alexander Philippov, Jérémy Mortier
سنة النشر: 2016
مصطلحات موضوعية: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Brewster's angle, 010308 nuclear & particles physics, Polarization in astronomy, Linear polarization, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Synchrotron radiation, FOS: Physical sciences, Astronomy and Astrophysics, Optical polarization, Astrophysics, Polarization (waves), 01 natural sciences, Current sheet, symbols.namesake, Optics, Pulsar, Space and Planetary Science, 0103 physical sciences, symbols, business, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics
الوصف: Polarization is a powerful diagnostic tool to constrain the site of the high-energy pulsed emission and particle acceleration in gamma-ray pulsars. Recent particle-in-cell simulations of pulsar magnetosphere suggest that high-energy emission results from particles accelerated in the equatorial current sheet emitting synchrotron radiation. In this study, we re-examine the simulation data to compute the phase-resolved polarization properties. We find that the emission is mildly polarized and that there is an anticorrelation between the flux and the degree of linear polarization (on-pulse: ~15%, off-pulse: ~30%). The decrease of polarization during pulses is mainly attributed to the formation of caustics in the current sheet. Each pulse of light is systematically accompanied by a rapid swing of the polarization angle due to the change of the magnetic polarity when the line of sight passes through the current sheet. The optical polarization pattern observed in the Crab can be well-reproduced for a pulsar inclination angle ~60 degrees and an observer viewing angle ~130 degrees. The predicted high-energy polarization is a robust feature of the current sheet emitting scenario which can be tested by future X-ray and gamma-ray polarimetry instruments.
5 pages, 3 figures, Accepted for publication in MNRAS Letters
اللغة: English
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ebac01b7e66578c0350a05592b7d2cd0
http://arxiv.org/abs/1609.00021
حقوق: OPEN
رقم الأكسشن: edsair.doi.dedup.....ebac01b7e66578c0350a05592b7d2cd0
قاعدة البيانات: OpenAIRE