Discovery of PSR J0523-7125 as a Circularly Polarized Variable Radio Source in the Large Magellanic Cloud
Discovery of PSR J0523-7125 as a Circularly Polarized Variable Radio Source in the Large Magellanic Cloud
复制标题
DOI：
10.3847/1538-4357/ac61dc
复制
发表时间：
2022-05
期刊：
影响因子：
--
通讯作者：
Yuanming Wang;T. Murphy;D. Kaplan;Teresa Klinner-Teo;A. Ridolfi;M. Bailes;F. Crawford;S. Dai
中科院分区：
文献类型：
--
作者：
Yuanming Wang;T. Murphy;D. Kaplan;Teresa Klinner-Teo;A. Ridolfi;M. Bailes;F. Crawford;S. Dai
我们报告了在澳大利亚平方公里阵列探路者（ASKAP）变量和慢瞬变（VAST）调查中发现的一颗高度圆偏振，可变，陡谱脉冲星。这颗脉冲星距离大麦哲伦星云中心约1 °，并且有一个显著的分数圆偏振，约为20%。我们使用MeerKAT和Parkes望远镜的观测发现了周期为322.5 ms的脉动，色散测量（DM）为157.5 pc cm − 3，旋转测量（RM）为+456 rad m − 2。这个DM将源PSR J0523 − 7125确定在大麦哲伦云（LMC）中。与LMC中的其他恒星相比，这个RM是极端的（是以前报道的最大恒星的两倍多）。它在1400 MHz和400 MHz的平均通量密度分别为1.21 mJy和1.25 mJy，是已知最明亮的射电望远镜之一。它可能是因为其非常陡峭的无线电频谱（频谱指数α <$− 3，其中S ν <$ν α）和宽脉冲轮廓（占空比<$35%）而避开了先前的发现。我们讨论了搜索不寻常的无线电源连续图像的影响，以及在麦哲伦云和超越河外星系。我们的研究结果突出了从射电连续谱图像中识别类星体，特别是极端类星体的可能性。未来的大规模无线电调查将为我们提供前所未有的机会，发现更多的彗星，并可能发现麦哲伦云以外最遥远的彗星。
We report the discovery of a highly circularly polarized, variable, steep-spectrum pulsar in the Australian Square Kilometre Array Pathfinder (ASKAP) Variables and Slow Transients (VAST) survey. The pulsar is located about 1° from the center of the Large Magellanic Cloud, and has a significant fractional circular polarization of ∼20%. We discovered pulsations with a period of 322.5 ms, dispersion measure (DM) of 157.5 pc cm−3, and rotation measure (RM) of +456 rad m−2 using observations from the MeerKAT and the Parkes telescopes. This DM firmly places the source, PSR J0523−7125, in the Large Magellanic Cloud (LMC). This RM is extreme compared to other pulsars in the LMC (more than twice that of the largest previously reported one). The average flux density of ∼1 mJy at 1400 MHz and ∼25 mJy at 400 MHz places it among the most luminous radio pulsars known. It likely evaded previous discovery because of its very steep radio spectrum (spectral index α ≈ −3, where S ν ∝ ν α ) and broad pulse profile (duty cycle ≳35%). We discuss implications for searches for unusual radio sources in continuum images, as well as extragalactic pulsars in the Magellanic Clouds and beyond. Our result highlighted the possibility of identifying pulsars, especially extreme pulsars, from radio continuum images. Future large-scale radio surveys will give us an unprecedented opportunity to discover more pulsars and potentially the most distant pulsars beyond the Magellanic Clouds.