一颗新型X射线脉冲星

用VLT对PDKEEPAAA脉冲星J1048-5832进行深光学成像

Deep optical imaging of the gamma-ray pulsar J1048-5832 with the VLT

PSR J1048-5832是一颗年轻的类船帆座脉冲星，最近被费米望远镜在伽马射线中探测到，也被钱德拉和XMM-牛顿望远镜在X射线中探测到。它为X射线可见的紧凑PWN提供动力。我们目前的深光学观测与ESO甚大望远镜寻找脉冲星及其星云的光学对应物，并探讨其多波长的发射特性。在V和R波段获得的数据，并与档案数据在其他光谱域进行了比较。我们没有在光学上探测到脉冲星，并推导出其亮度的信息上限R > 28.1等和V > 28.4等。利用红团星方法，我们估计了脉冲星的星际消光为2等，这与X射线吸收柱密度一致。相应的距离与色散测量距离一致。我们重新分析了Chandra X射线数据，并将去红上限与脉冲星未吸收的X射线光谱进行了比较。我们发现，就其光学X射线光谱特性，这伽马射线脉冲星是没有区别于其他恒星在这两个范围内检测到。然而，像船帆座脉冲星一样，它在光学和X射线方面非常低效。在与脉冲星X射线星云重叠的十几个光源中，我们发现了一个V = 26.9和R = 26.3等的光源，其颜色比场星略蓝，与脉冲星星云特征的特有颜色一致。它的位置与脉冲星X射线星云的一个相对明亮的特征相吻合，类似于蟹状星云，距离脉冲星2角秒。我们建议将此源作为该功能的对应候选人。基于对脉冲星的大量星际消光及其光学效率低下，应在更长的波长上进行进一步的光学研究。

Chandra measurements of the proper motion of the $γ$-ray pulsar J0633+0632

We measured the proper motion of a $γ$-ray radio-quiet pulsar J0633+0632 using Chandra observations performed in 2009 and 2017. The measured proper motion is $53\pm15$~mas~yr$^{-1}$. We found that the proper motion direction does not follow the extension of the J0633+0632 pulsar wind nebula. The J0633+0632 pulsar wind nebula therefore can be a jet-like feature or a misaligned outflow. We also discuss a possible birth cite of the pulsar.

Observations of the $γ$-ray pulsar J1932+1916 in X-rays

We present the analysis of the archival Suzaku and Swift X-ray observations of the young $γ$-ray pulsar J1932+1916 field. The data revealed a point-like object at the $γ$-ray position of the pulsar and diffuse X-ray emission around it. Spectra of the point-like source and diffuse emission are well-described by absorbed power-law models with spectral parameters typical for pulsar plus pulsar wind nebula systems. Therefore we suggest that Suzaku and Swift detected the X-ray counterpart of PSR J1932+1916. Assuming this interpretation, we constrain the distance to the pulsar in the range of 2-6 kp…

Detection of radio emission from the gamma-ray pulsar J1732-3131 at 327 MHz

Although originally discovered as a radio-quiet gamma-ray pulsar, J1732-3131 has exhibited intriguing detections at decameter wavelengths. We report an extensive follow-up of the pulsar at 327 MHz with the Ooty radio telescope. Using the previously observed radio characteristics, and with an effective integration time of 60 hrs, we present a detection of the pulsar at a confidence level of 99.82%. The 327 MHz mean flux density is estimated to be 0.5-0.8 mJy, which establishes the pulsar to be a steep spectrum source and one of the least-luminous pulsars known to date. We also phase-aligned the…

Gamma-Ray毫秒脉冲星光谱和光度函数的新确定

A New Determination of the Spectra and Luminosity Function of Gamma-Ray Millisecond Pulsars

在这篇文章中，我们回顾了毫秒双星和球状星团观测到的伽马射线辐射。基于费米伽玛射线空间望远镜5.6年的观测数据，我们报道了61个毫秒级超新星的伽玛射线能谱，发现大多数能谱符合指数截止的幂律，能谱峰值在~1-2 GeV（$E^2 dN/dE$单位）附近。此外，虽然大多数球状星团表现出类似的光谱形状，我们确定了一些显着较软的光谱。我们还确定的伽玛射线光度函数的毫秒双星使用人口发现在附近的领域的银河系，并在球状星团47图克坦。我们发现，从球状星团观察到的伽马射线发射主要由相对少量的明亮毫秒脉冲星主导，而低光度脉冲星仅占总通量的一小部分。我们的研究结果还表明，毫秒双星的伽马射线发射是更各向同性和较强的光束比在X射线波长的发射。此外，所观察到的表观伽马射线效率的分布提供了支持槽隙或外间隙模型，其中伽马射线发射起源于接近中子星的磁极的区域（极帽模型）。