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arXiv 0910.1608astro-ph.HE
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第一个费米望远镜大面积脉冲星表(Gamma-ray)

The First Fermi Large Area Telescope Catalog of Gamma-ray Pulsars

A. A. Abdo

摘要:

自费米伽马射线太空望远镜(原GLAST)发射以来,已知伽马射线天体的数量急剧增加,这为研究这些高能天体的数量提供了第一次机会。这个目录总结了46个高置信度的脉冲探测,使用费米的主要仪器大面积望远镜(LAT)拍摄的前六个月的数据。通过在LAT观测到的明亮伽马射线源位置或根据其他波长的观测怀疑是中子星的物体位置搜索脉冲信号,发现了16颗以前未知的中子星。脉冲伽马射线发射是从24个已知的射电天文台中发现的,使用的是从监测射电天文台中得到的星历表(计时解)。这些新的伽马射线双星中有八个是毫秒双星。脉冲能谱可以用指数截止的幂律来描述,截止能量在1至5 GeV的范围内。这些中子星的旋转能量损失率(\dot{E})跨越50年,从~ 3x 10 ^{33} erg/s到5x 10 ^{38} erg/s,转换为伽马射线辐射的表观效率从~0.1%到1不等,尽管距离的不确定性使效率估计变得复杂。脉冲形状显示出相当大的差异,但大约75%的伽马射线脉冲轮廓有两个峰值,相隔>0.2的旋转相位。对于大多数的类星体来说,伽马射线辐射似乎主要来自外磁层,而极冠辐射对于剩下的少数仍然是合理的。最后,这些发现表明,伽马射线选择的年轻超新星的出生率与它们的射电选择的表亲相当,所有年轻伽马射线探测到的超新星的出生率是预期的银河系超新星率的很大一部分。

英文摘要:

The dramatic increase in the number of known gamma-ray pulsars since the launch of the Fermi Gamma-ray Space Telescope (formerly GLAST) offers the first opportunity to study a population of these high-energy objects. This catalog summarizes 46 high-confidence pulsed detections using the first six months of data taken by the Large Area Telescope (LAT), Fermi's main instrument. Sixteen previously unknown pulsars were discovered by searching for pulsed signals at the positions of bright gamma-ray sources seen with the LAT, or at the positions of objects suspected to be neutron stars based on observations at other wavelengths. Pulsed gamma-ray emission was discovered from twenty-four known pulsars by using ephemerides (timing solutions) derived from monitoring radio pulsars. Eight of these new gamma-ray pulsars are millisecond pulsars. The pulsed energy spectra can be described by a power law with an exponential cutoff, with cutoff energies in the range 1 to 5 GeV. The rotational energy loss rate (\dot{E}) of these neutron stars spans 5 decades, from ~3x10^{33} erg/s to 5x10^{38} erg/s, and the apparent efficiencies for conversion to gamma-ray emission range from ~0.1% to unity, although distance uncertainties complicate efficiency estimates. The pulse shapes show substantial diversity, but roughly 75% of the gamma-ray pulse profiles have two peaks, separated by >0.2 of rotational phase. For most of the pulsars, gamma-ray emission appears to come mainly from the outer magnetosphere, while polar-cap emission remains plausible for a remaining few. Finally, these discoveries suggest that gamma-ray-selected young pulsars are born at a rate comparable to that of their radio-selected cousins and that the birthrate of all young gamma-ray-detected pulsars is a substantial fraction of the expected Galactic supernova rate.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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