| Polarization of GRB prompt emission and its application to POLAR’s data |
| |
| 作者姓名： | Mi-Xiang Lan Xue-Feng Wu Zi-Gao Dai |
| |
| 作者单位： | Center for Theoretical Physics and College of Physics;Purple Mountain Observatory;School of Astronomy and Space Science;Key Laboratory of Modern Astronomy and Astrophysics（Nanjing University） |
| |
| 基金项目： | supported by the National Key Research and Development Program of China(Grant No.2017YFA0402600);the National Natural Science Foundation of China(NSFC)(Grant Nos.11573014,11673068,11725314,11833003 and 11903014);partially supported by the Key Research Program of Frontier Sciences(QYZDB-SSW-SYS005);the Strategic Priority Research Program“Multi-waveband gravitational wave Universe”(Grant No.XDB23040000)of the Chinese Academy of Sciences;the“333 Project”of Jiangsu province;supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK 20171109);the Fundamental Research Funds for the Central Universities;in part by NSFC(Grant No.11847310);the Seeds Funding of Jilin University。 |
| |
| 摘 要： | Synchrotron emission polarization is very sensitive to the magnetic field configuration.Recently,polarization of synchrotron emission with a mixed(SM)magnetic field in the gamma-ray burst(GRB)afterglow phase has been developed.Here,we apply these SM models to the GRB prompt phase and compare their polarization properties with that of synchrotron emission in purely ordered(SO)magnetic field.We find that the polarization properties in an SM model are very similar to these in a corresponding SO model(e.g.,synchrotron emission in a mixed magnetic field with an aligned ordered part(SMA)and synchrotron emission with a purely ordered aligned magnetic field(SOA)),only with a lower polarization degree(PD).We also discuss the statistical properties of the models.We find PDs of the simulated bursts are concentrated around 25%for both SOA and synchrotron emission in a purely ordered toroidal magnetic field(SOT),while they can range from 0%to 25%for SMA and synchrotron emission in a mixed magnetic field with a toroidal ordered part(SMT),depending onξ_B value,i.e.,the ratio of magnetic reduction of the ordered magnetic field over that of random magnetic field.From statistics,if PDs of majority GRBs are non-zero,then it favors SO and SM models.Further,if there are some bright GRBs with prominently lower PDs than that of the majority GRBs,it favors SOT(SMT)models;if all the bright GRBs have comparable PDs with the majority ones,it favors SOA(SMA)models.Finally,we apply our results to POLAR’s data and find that~10%time-integrated PDs of the observed bursts favor SMA and SMT models,and theξ_B parameter of these bursts is constrained to be around 1.135.
|
| 关 键 词： | gamma-ray burst:general magnetic fields POLARIZATION radiation mechanisms:nonthermal |
Polarization of GRB prompt emission and its application to POLAR's data |
| |
| Mi-Xiang Lan,Xue-Feng Wu,Zi-Gao Dai.Polarization of GRB prompt emission and its application to POLAR's data[J].Research in Astronomy and Astrophysics,2021(3):43-56. |
| |
| Abstract: | |
| |
| Keywords: | |
| 本文献已被 CNKI 维普 等数据库收录！ |
|
