PSR B1259-63的极冠几何结构研究  

A Study on the Polar Cap Geometry of PSR B1259-63

作　　者：买买提.阿布力孜 艾力.伊沙木丁 阿地里.托合提 

机构地区：[1]新疆大学物理科学与技术学院,新疆乌鲁木齐830046 [2]新疆大学国家天文台联合天体物理中心,新疆乌鲁木齐830046 [3]中国科学院新疆天文台,新疆乌鲁木齐830011

出　　处：《新疆大学学报（自然科学版）》2011年第3期346-351,共6页Journal of Xinjiang University(Natural Science Edition)

基　　金：国家自然科学基金(No.10973026)

摘　　要：本文利用欧洲脉冲星观测网(EPN)数据库里PSR B1259-63在1.52GHz、4.68GHz和8.28GHz三个频率上的线偏振位置角观测数据研究这颗脉冲星可能的极冠几何结构.本研究分别假设了PSR B1259-63是平行转子和垂直转子两种情况,用脉冲星旋转矢量模型(RVM)对线偏振位置角观测数据进行了最小二乘法拟合研究.在平行转子假设下,对三个频率观测结果拟合得到了两套可能的模型(a、b)参数,模型(a)的α=10.0±0.5、β=0.5±0.3,模型(b)的α=36.3±2、β=9±2,这与Manchester和Johnston在1995年得到的结果基本一致.在垂直转子假设下,对三个频率观测的主脉冲(MP)和中间脉冲(IP)数据拟合得到两个磁极参数分别为αMP=83±2、βMP=3±1和αIP=97±1、βIP=17±1,表明主脉冲和中间脉冲可能分别源自脉冲星两个磁极,不能排除该星是垂直转子的可能性.目前的观测数据还不能明确限定PSR B1259-63的极冠几何结构,有必要进行更深入的观测与研究.We study the polar cap geometry of PSR B1259-63 by fitting the position angle data of the pulsar for rotating vector model （RVM）. The observational data at 1.52 GHz, 4.68 GHz and 8.28 GHz used in this paper come from the European Pulsar Network Data Archive. Under the nearly-aligned-rotator assumption and nearly-orthogonal-rotator assumption, the least-squares algorithm fitting on the position angle data at three frequencies is carried out. In case of the assumption of nearly aligned rotator, the parameters for two models, i.e. a = 10.0° ±0.5°,β = 0.5° ±0.3° for model （a） and a = 36.3° ±2°,β = 9° ±2° for model （b）, are obtained. Our results for the nearly-aligned-rotator assumption are consistent with that of Manchester and Johnston （1995）. Under the assumption of nearly orthogonal rotator, we obtain αMP = 83°±2°, βMP =-3°± 1° and aIP = 97°± 1°, βIP = -17° ± 1° by fitting for the position angle data of the main pulse （MP） and the inter pulse （IP） respectively. In this case, the results indicated that the main pulse and inter pulse of the pulsar are likely to originated from two different magnetic poles, so the possibility of the pulsar is a nearly orthogonal rotator can not be excluded. The polar cap geometry of PSR B1259-63 can not be solved by fitting RVM to the observational data obtained so far. Further observations and studies are strongly suggested.

关 键 词：脉冲星 PSR B1259—63 偏振 RVM 

分 类 号：P141.4[天文地球—天体物理]