论文标题
银河磁铁的“慢速”无线电爆发？
"Slow" Radio Bursts from Galactic Magnetars?
论文作者
论文摘要
最近，在一次X射线爆发中，从银河磁铁SGR J1935+2154中检测到了一个快速的无线电爆发，即FRB 200428。这表明磁铁可以制造FRB。另一方面，SGR J1935+2154的大多数X射线爆发与FRB无关。这种罕见的FRB-SGR-Burst关联的可能原因是，FRB发射比SGR爆发发射要狭窄得多。如果这种解释是正确的，人们会期望在狭窄的发射光束外面检测到带有视角的无线电突发。由于涉及较小的多普勒因子，这些“缓慢”的无线电爆发（SRB）将具有更大的宽度和较低的通量密度。我们得出了两个“封闭关系”，以判断长时间，较不发光的无线电爆发是否可能是SRB。 BSA LPI射电望远镜从SGR J1935+2154检测到的2.2-S，308 JY MS，111 MHz无线电爆发可能是这样的SRB。如果相应的FRB具有狭窄的频谱，那么从同一来源快速检测到的2毫秒，60 mjy MS微弱的爆发也可能是SRB。如果FRB梁狭窄，则SRB的SRB应该比银河系磁铁的FRB多。缺乏从磁铁中检测到丰富的SRB，这将不利于以下假设：所有SGR爆发都与窄梁FRB相关。
Recently, one fast radio burst, FRB 200428, was detected from the Galactic magnetar SGR J1935+2154 during one X-ray burst. This suggests that magnetars can make FRBs. On the other hand, the majority of X-ray bursts from SGR J1935+2154 are not associated with FRBs. One possible reason for such rarity of FRB-SGR-burst associations is that the FRB emission is much more narrowly beamed than the SGR burst emission. If such an interpretation is correct, one would expect to detect radio bursts with viewing angles somewhat outside the narrow emission beam. These "slow" radio bursts (SRBs) would have broader widths and lower flux densities due to the smaller Doppler factor involved. We derive two "closure relations" to judge whether a long, less luminous radio burst could be an SRB. The 2.2-s, 308 Jy ms, 111 MHz radio burst detected from SGR J1935+2154 by the BSA LPI radio telescope may be such an SRB. The 2-ms, 60 mJy ms faint burst detected by FAST from the same source could be also an SRB if the corresponding FRB has a narrow spectrum. If the FRB beam is narrow, there should be many more SRBs than FRBs from Galactic magnetars. The lack of detection of abundant SRBs from magnetars would disfavor the hypothesis that all SGR bursts are associated with narrow-beam FRBs.
