Agile对“软”伽马射线脉冲星PSR B1509-58的观测
高能天体物理现象
2015-05-19 v1
摘要
我们展示了Agile对PSR B1509-58进行的新观测结果，观测时间跨度为2.5年，基于当前数据子集获得的探测结果。能量高于30 MeV的光变曲线调制显著性达到5置信水平，其光变曲线与Comptel在30 MeV以下发现的结果相似：一个宽的不对称第一峰值在射电峰值后0.39 +/- 0.02周期处达到最大，加上第二个峰值在0.94 +/- 0.03处。由Comptel和Agile探测到的脉冲通量的伽马射线能谱分布可由幂律（光子指数alpha=1.87+/-0.09）很好地描述，并在E_c=81 +/- 20 MeV处存在显著截断，这是迄今在伽马射线脉冲星中观测到的最软能谱。假设距离为5.2 kpc，E > 1 MeV的脉冲星光度为 erg/s，这意味着自旋减速转化为伽马射线的效率约为0.03。PSR B1509-58能谱中不寻常的软截断已在极冠模型框架内被解释为该脉冲星强磁场中奇特的光子分裂过程的特征。在这种解释下，我们的能谱将发射点的磁高度限制在距中子星表面3公里处，这意味着衰减可能不像之前认为的那样强，因为在磁层中磁场变得太低而无法维持光子分裂的区域，对产生可以替代光子分裂。对于外间隙场景或双极冠模型，需要从射电波段获得对发射几何结构的更好约束，以确定模型再现Agile光变曲线和能谱所需的条件是否与偏振测量相匹配。
引用
@article{arxiv.1009.0021,
title = {Agile Observations of the "Soft" Gamma-Ray Pulsar PSR B1509-58},
author = {M. Pilia and A. Pellizzoni and A. Trois and F. Verrecchia and P. Esposito and P. Weltevrede and S. Johnston and M. Burgay and A. Possenti and E. Del Monte and F. Fuschino and P. Santolamazza and A. Chen and A. Giuliani and P. Caraveo and S. Mereghetti and M. Tavani and A. Argan and E. Costa and N. D'Amico and A. De Luca and Y. Evangelista and M. Feroci and F. Longo and M. Marisaldi and G. Barbiellini and A. Bulgarelli and P. W. Cattaneo and V. Cocco and F. D'Ammando and G. De Paris and G. Di Cocco and I. Donnarumma and M. Fiorini and T. Froysland and M. Galli and F. Gianotti and C. Labanti and I. Lapshov and F. Lazzarotto and P. Lipari and A. Morselli and L. Pacciani and F. Perotti and G. Piano and P. Picozza and M. Prest and G. Pucella and M. Rapisarda and A. Rappoldi and S. Sabatini and P. Soffitta and M. Trifoglio and E. Vallazza and S. Vercellone and V. Vittorini and A. Zambra and D. Zanello and C. Pittori and F. Lucarelli and P. Giommi and L. Salotti and G. F. Bignami},
journal= {arXiv preprint arXiv:1009.0021},
year = {2015}
}
备注
17 pages, 2 figures, accepted for publication in ApJ