This paper describes an analysis of the NuSTAR data of the fastest-rotating magnetar 1E 1547$-$5408, acquired in 2016 April for a time lapse of 151 ks. The source was detected with a 1-60 keV flux of $1.7 \times 10^{-11}$ ergs s$^{-1}$ cm$^{-2}$, and its pulsation at a period of $2.086710(5)$ sec. In 8-25 keV, the pulses were phase-modulated with a period of $T=36.0 \pm 2.3$ ks, and an amplitude of $\sim 0.2$ sec. This reconfirms the Suzaku discovery of the same effect at $T=36.0 ^{+4.5}_{-2.5} $ ks, made in the 2009 outburst. These results strengthen the view derived from the Suzaku data, that this magnetar performs free precession as a result of its axial deformation by $\sim 0.6 \times 10^{-4}$, possibly caused by internal toroidal magnetic fields reaching $\sim 10^{16}$ G. Like in the Suzaku case, the modulation was not detected in energies below $\sim 8$ keV. Above 10 keV, the pulse-phase behaviour, including the 36 ks modulation parameters, exhibited complex energy dependences: at $\sim 22$ keV, the modulation amplitude increased to $\sim 0.5$ sec, and the modulation phase changed by $\sim 65^\circ$ over 10--27 keV, followed by a phase reversal. Although the pulse significance and pulsed fraction were originally very low in $>10$ keV, they both increased noticeably, when the arrival times of individual photons were corrected for these systematic pulse-phase variations. Possible origins of these complex phenomena are discussed, in terms of several physical processes that are specific to ultra-strong magnetic fields.
我们报告了位于超新星遗迹CTB 109中的磁星1 E 2259+586的新的宽带光谱和时间观测结果。我们的数据是同时获得的核光谱望远镜阵列（NuSTAR）和雨燕，并涵盖从0.5-79千电子伏的能量范围。我们目前的脉冲配置文件在不同的能量带，并比较他们以前的RXTE结果。NuSTAR的数据显示脉动高于20千电子伏的第一次，我们报告的证据表明，在双峰脉冲轮廓的脉冲之一的位置与能量的变化。磁星的脉冲分数示出强烈的能量增加。我们的光谱分析表明，软X射线光谱的特点是吸收双黑体或黑体加幂律模型与以前的报告。然而，我们新的硬X射线数据表明，需要一个额外的组成部分，如幂律，来描述NuSTAR和Swift光谱。我们还适合的数据与最近开发的日冕外流模型Beloborodov的硬X射线发射磁星。从磁星表面的环流出是统计上优选的流出从极帽。
The magnetar SGR J1745-2900 located in the vicinity of the supermassive black hole Sgr A$^{\star}$ was detected during its X-ray outburst with the Swifht/XRT telescope in April 2013. For several months after its detection the source was observed with the NuSTAR observatory, which allowed pulsations with a period $\sim3.76$ s to be recorded. Using these observations, we have studied in detail the dependence of the pulse profile and the pulsed fraction on the energy and intensity of the magnetar. The pulsed fraction in the 3-5 and 5-10 keV energy bands is shown to be 40-50%, slightly increasing …
3A 1954+319 has been classified for a long time as a symbiotic X-ray binary, hosting a slowly rotating neutron star and an aged M red giant. Recently, this classification has been revised thanks to the discovery that the donor star is an M supergiant. This makes 3A 1954+319 a rare type of high mass X-ray binary consisting of a neutron star and a red supergiant donor. In this paper, we analyse two archival and still unpublished XMM-Newton and NuSTAR observations of the source. We perform a detailed hardness ratio-resolved spectral analysis to search for spectral variability that could help inve…
Some Hydrogen-poor superluminous supernovae are likely powered by a magnetar central engine, making their luminosity larger than common supernovae. Although a significant amount of X-ray flux is expected from the spin down of the magnetar, direct observational evidence is still to be found, giving rise to the "missing energy" problem. Here we present NuSTAR observations of nearby SN 2018hti 2.4y (rest frame) after its optical peak. We expect that, by this time, the ejecta have become optically thin for photons more energetic than about 15keV. No flux is detected at the position of the supernov…
A few years after its discovery as a magnetar, SGR J1935+2154 started a new burst-active phase on 2020 April 27, accompanied by a large enhancement of its X-ray persistent emission. Radio single bursts were detected during this activation, strengthening the connection between magnetars and fast radio bursts. We report on the X-ray monitoring of SGR J1935+2154 from ~3 days prior to ~3 weeks after its reactivation, using Swift, NuSTAR, and NICER. We detected X-ray pulsations in the NICER and NuSTAR observations, and constrained the spin period derivative to |Pdot| < 3e-11 s/s (3 sigma c.l.). The…
The long-term enhanced brightness of the magnetar 1E 1547.0-5408
我们提出了自2004年2月以来的磁星1 E 1547.0-5408的X射线发射特性的演变，在一段时间内，涵盖三个爆发。我们分析了Swift，NuSTAR，Chandra和XMM-Newton X射线卫星的新观测和档案观测。在过去的9年中，该源的软X射线通量相对稳定，为$\approx$ 10 $^{-11}$ erg cm $^{-2}$ s $^{-1}$（0.3-10 keV），比2009年最后一次爆发峰值时的通量弱一个数量级，但比2006年的水平大$\sim$ 30倍。从2016年4月和2019年2月最近的两次NuSTAR观测中提取的宽带光谱显示了高达$\sim$ 70 keV的微弱硬X射线发射。它的光谱可以用平坦的幂律分量来描述，它的通量是$\sim$ $7 \times 10^{-12}$ erg cm $^{-2}$ s $^{-1}$（10-70 keV），比2009年爆发的峰值小了$\sim$ 20倍。硬X射线光谱形状随时间显著变平，这与软X射线成分的整体冷却趋势不一致。从这些NuSTAR点提取的脉冲轮廓显示了形状和振幅随能量（高达$\approx$ 25 keV）的变化。我们的分析显示，1 E 1547.0-5408的通量还没有衰减到2006年的水平，并且源已经在稳定的高强度状态徘徊了几年。这可能表明，磁星可以在不同的持续状态之间跳跃，这些状态可能与爆发事件有关，…
Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
PSR J1622-4950的新无线电（MeerKAT和Parkes）和X射线（XMM-Newton，Swift，Chandra和NuSTAR）观测表明，至少自2015年初以来处于静止状态的磁星在2017年3月19日至4月5日之间重新激活。无线电通量密度虽然是可变的，但大约是休眠状态的100倍。重新激活后一个月的X射线通量至少比静止时大800倍，并且在111+/-19天的时间尺度上呈指数衰减。这种高通量状态，加上无线电衍生的旋转星历，使第一次探测到X射线脉动的磁星。在5%时，0.3-6 keV脉冲部分与磁星观察到的最小值相当。从偏振射电辐射推断的脉冲星总体几何形状似乎与6-8年前确定的大致一致。然而，旋转矢量模型拟合表明，我们现在看到的无线电发射来自磁层中与以前不同的位置。这表明磁星的无线电发射可以不同于普通磁星的一种新方式。中子星上的扭矩变化迅速而不稳定，这在磁星爆发后很常见，在重新激活的六个月内变化了7倍。
X-ray timing properties of the magnetar SGR 1900+14 were studied, using the data taken with Suzaku in 2009 and NuSTAR in 2016, for a time lapse of 114 ks and 242 ks, respectively. On both occasions, the object exhibited the characteristic two-component spectrum. The soft component, dominant in energies below $\sim 5$ keV, showed a regular pulsation, with a period of $P=5.21006$ s as determined with the Suzaku XIS, and $P=5.22669$ with NuSTAR. However, in $\gtrsim 6$ keV where the hard component dominates, the pulsation became detectable with the Suzaku HXD and NuSTAR, only after the data were …
Magnetar-like activity from the central compact object in the SNR RCW103
位于SNR RCW 103中心的中央致密天体（CCO）（命名为1 E 161348-5055）的6.67小时周期和可变X射线通量一直难以在孤立中子星或双星系统的标准场景中解释。2016年6月22日，雨燕号上的爆发警报望远镜（BAT）从1 E 161348-5055方向探测到一个类似磁星的短X射线爆发，也与一个大型长期X射线爆发相吻合。在这里，我们报告了钱德拉，NuSTAR和Swift（BAT和XRT）在2016年爆发高峰期间对这个特殊来源的观测。特别是，我们研究了这种类磁星爆发的性质，我们在爆发期间发现了CCO光谱中的硬X射线尾，并研究了它的长期爆发历史（从1999年到2016年7月）。我们发现1 E 161348-5055的发射特性与它是一颗磁星一致。然而，在这种情况下，6.67小时的周期只能被解释为这个强磁化中子星的旋转周期，因此，它代表了有史以来最慢的脉冲星检测到的数量级。我们简要地讨论了可行的慢下来的情况下，有利于图片涉及一段时间的回落吸积后，超新星爆炸，类似的调用（虽然在不同的制度），以解释其他CCO的“反磁星”的情况。
Pulsed Infrared Emission from Magnetar 4U 0142+61 Detected by JWST
NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；Center for Research and Exploration in Space Science and Technology, NASA/GSFC（NASA/GSFC空间科学与技术研究探索中心）；The Catholic University of America（美利坚天主教大学）；Pennsylvania State University（宾夕法尼亚州立大学）；University of Oxford（牛津大学）；Center for Space Sciences and Technology, University of Maryland, Baltimore County（马里兰大学巴尔的摩县分校空间科学与技术中心）；The George Washington University（乔治华盛顿大学）
The soft gamma-ray repeater candidate SGR 0755$-$2933 was discovered in 2016 by Swift/BAT, which detected a short ($\sim$30 ms) powerful burst typical of magnetars. To understand the nature of the source, we present here an analysis of follow-up observations of the tentative soft X-ray counterpart of the source obtained with Swift/XRT, NuSTAR and Chandra. From our analysis we conclude that, based on the observed counterpart position and properties, it is actually not a soft gamma ray repeater but rather a new high mass X-ray binary. We suggest to refer to it as 2SXPS J075542.5$-$293353. We con…
Using X-ray observations from the NuSTAR and Swift satellites, we present temporal and spectral properties of an intermediate polar (IP) IGR J16547-1916. A persistent X-ray period at ~ 546 s confirming the optical spin period obtained from previous observations is detected. The detection of a strong X-ray spin pulse reinforces the classification of this system as an intermediate polar. The lack of orbital or side-band periodicities in the X-rays implies that the system is accreting predominantly via a disk. A variable covering absorber appears to be responsible for the spin pulsations in the l…
Swift J1818.0-1607 is a radio-loud magnetar with a spin period of 1.36 s and a dipolar magnetic field strength of B~3E14 G, which is very young compared to the Galactic pulsar population. We report here on the long-term X-ray monitoring campaign of this young magnetar using XMM-Newton, NuSTAR, and Swift from the activation of its first outburst in March 2020 until October 2021, as well as INTEGRAL upper limits on its hard X-ray emission. The 1-10 keV magnetar spectrum is well modeled by an absorbed blackbody with a temperature of kT_BB~1.1 keV, and apparent reduction in the radius of the emitt…
Evidence for 1.01 s Pulsations of the Central Compact Object in the Supernova Remnant RCW 103 with ASCA, XMM-Newton, and NuSTAR
The University of Tokyo（东京大学）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo（东京大学宇宙物质量子前沿研究センター（WPI））；Institute of Space and Astronautical Science（宇宙科学研究所）；Department of Physics, Kyoto University（京都大学理学部物理学科）；RIKEN（理化学研究所）
The magnetar SGR J1935+2154 underwent a new active episode on 2020 April 27-28, when a forest of hundreds of X-ray bursts and a large enhancement of the persistent flux were detected. For the first time, a radio burst with properties similar to those of fast radio bursts and with a X-ray counterpart was observed from this source, showing that magnetars can power at least a group of fast radio bursts. In this paper, we report on the X-ray spectral and timing properties of SGR J1935+2154 based on a long-term monitoring campaign with Chandra, XMM-Newton, NuSTAR, Swift and NICER covering a time sp…
We report the radio and high-energy properties of a new outburst from the radio-loud magnetar 1E 1547.0$-$5408. Following the detection of a short burst from the source with Swift-BAT on 2022 April 7, observations by NICER detected an increased flux peaking at $(6.0 \pm 0.4) \times 10^{-11}$ erg s$^{-1}$ cm$^{-2}$ in the soft X-ray band, falling to the baseline level of $1.7\times10^{-11}$ erg s$^{-1}$ cm$^{-2}$ over a 17-day period. Joint spectroscopic measurements by NICER and NuSTAR indicated no change in the hard non-thermal tail despite the prominent increase in soft X-rays. Observations …
After 15 years, in late 2018, the magnetar XTE J1810-197 underwent a second recorded X-ray outburst event and reactivated as a radio pulsar. We initiated an X-ray monitoring campaign to follow the timing and spectral evolution of the magnetar as its flux decays using Swift, XMM-Newton, NuSTAR, and NICER observations. During the year-long campaign, the magnetar reproduced similar behaviour to that found for the first outburst, with a factor of two change in its spin-down rate from $\sim7.2\times10^{-12}$ s s$^{-1}$ to $\sim1.5\times10^{-11}$ s s$^{-1}$ after two months. Unique to this outburst,…
