DISCOVERY OF PULSED ?-RAYS FROM THE YOUNG RADIO PULSAR PSR J1028-5819 WITH THE FERMI LARGE AREA TELESCOPE
DISCOVERY OF PULSED ?-RAYS FROM THE YOUNG RADIO PULSAR PSR J1028-5819 WITH THE FERMI LARGE AREA TELESCOPE
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使用费米大面望远镜发现来自年轻射电脉冲星 PSR J1028-5819 的脉冲 γ 射线
DOI：
10.1088/0004-637x/695/1/l72
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发表时间：
2009
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通讯作者：
Abdo A
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作者：
Abdo A
射电脉冲星PSR J1028 - 5819最近在高能伽马射线实验望远镜（EGRET）源3EG J1027 - 5817的误差圆中进行高频搜索（3.1 GHz）时发现。这颗年轻的脉冲星的自旋下降功率足够大，使其很可能是EGRET源的对应物。我们在此报告费米伽马射线太空望远镜上的大视场望远镜（LAT）在早期观测中发现PSR J1028− 5819的γ射线脉动。γ射线光变曲线显示出两个尖锐的峰值，相位分离为0.460±0.004，在相位上落后于非常窄的无线电脉冲0.200±0.003，与其他已知的γ射线天体非常相似。测量的γ射线通量给出脉冲星的效率为10%-20%（对于外磁层束模型）。在目前的费米数据中，没有发现周围有脉冲星风星云的证据，但对相关发射的限制很弱，因为源位于一个拥挤的区域，背景发射很高。然而，LAT提供的改进的角分辨率使得先前的COS-B和EGRET源探测能够分解为至少两个不同的源，其中一个现在被识别为PSR J1028− 5819。
Radio pulsar PSR J1028− 5819 was recently discovered in a high-frequency search (at 3.1 GHz) in the error circle of the Energetic Gamma-Ray Experiment Telescope (EGRET) source 3EG J1027− 5817. The spin-down power of this young pulsar is great enough to make it very likely the counterpart for the EGRET source. We report here the discovery of γ-ray pulsations from PSR J1028− 5819 in early observations by the Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope. The γ-ray light curve shows two sharp peaks having phase separation of 0.460±0.004, trailing the very narrow radio pulse by 0.200±0.003 in phase, very similar to that of other known γ-ray pulsars. The measured γ-ray flux gives an efficiency for the pulsar of∼ 10–20%(for outer magnetosphere beam models). No evidence of a surrounding pulsar wind nebula is seen in the current Fermi data but limits on associated emission are weak because the source lies in a crowded region with high background emission. However, the improved angular resolution afforded by the LAT enables the disentanglement of the previous COS-B and EGRET source detections into at least two distinct sources, one of which is now identified as PSR J1028− 5819.