Evidence for an abundant old population of Galactic ultra long period magnetars and implications for fast radio bursts
Evidence for an abundant old population of Galactic ultra long period magnetars and implications for fast radio bursts
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银河系超长周期磁星数量丰富的证据及其对快速射电爆发的影响
DOI：
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发表时间：
2022
影响因子：
4.8
通讯作者：
A. J. van der Horst
中科院分区：
文献类型：
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作者：
P. Beniamini;Z. Wadiasingh;J. Hare;K. Rajwade;G. Younes;A. J. van der Horst
最近的两个发现，即PSR J0901 - 4046和GLEAM-X J162759.5 - 523504.3（以下简称GLEAM-X J1627），已经证实了现存的一批具有长周期（分别为76 s和1091 s）的射电大声周期源，其发射很难用旋转损失来解释。我们认为，GLEAM-X J1627是一个高度磁化的对象符合磁星（超长周期磁星-ULPM），并证明它不太可能是一个磁性或旋转动力的白色矮星。通过研究这些来源与以前检测到的物体，我们发现至少有少数有希望的候选人银河系ULPM。这些物体的探测意味着在我们的银河系中，PSR J0901 - 4046和GLEAM-X J1627的数量分别为13000和500。这些源密度，以及因未检测到热X射线而产生的冷却年龄限制、银河系偏移、定时稳定性和偶极自旋下降限制，都意味着ULPM候选者比已确认的银河系磁星要古老得多，并且它们的形成通道是一个共同的通道。它们的存在意味着类磁星磁场的广泛存在已经有好几百万年了，这与已证实的银河系磁星的推断行为不同。ULPMs也可以构成第二类FRB祖细胞，其可以自然地表现出非常长的周期性活动窗口。最后，我们表明，现有的无线电活动对检测这样的物体有偏见，并讨论了未来的无线电和X射线调查，以确定更多这样的对象的策略。我们估计SKA-MID和DSA-2000还可以探测到${cal O}（100）$更多的此类天体。
Two recent discoveries, namely PSR J0901-4046 and GLEAM-X J162759.5-523504.3 (hereafter GLEAM-X J1627), have corroborated an extant population of radio-loud periodic sources with long periods (76 s and 1091 s respectively) whose emission can hardly be explained by rotation losses. We argue that GLEAM-X J1627 is a highly-magnetized object consistent with a magnetar (an ultra long period magnetar - ULPM), and demonstrate it is unlikely to be either a magnetically or a rotationally-powered white dwarf. By studying these sources together with previously detected objects, we find there are at least a handful of promising candidates for Galactic ULPMs. The detections of these objects imply a substantial number, N ≳ 13000 and N ≳ 500 for PSR J0901–4046 like and GLEAM-X J1627 like objects, respectively, within our Galaxy. These source densities, as well as cooling age limits from non-detection of thermal X-rays, Galactic offsets, timing stability and dipole spindown limits, all imply the ULPM candidates are substantially older than confirmed Galactic magnetars and that their formation channel is a common one. Their existence implies widespread survival of magnetar-like fields for several Myr, distinct from the inferred behaviour in confirmed Galactic magnetars. ULPMs may also constitute a second class of FRB progenitors which could naturally exhibit very long periodic activity windows. Finally, we show that existing radio campaigns are biased against detecting objects like these and discuss strategies for future radio and X-ray surveys to identify more such objects. We estimate that ${cal O}(100)$ more such objects should be detected with SKA-MID and DSA-2000.