标题： 磁星候选体1E 1048.1-5937的突发且同时的短时脉冲流量增强 显示英文标题

标题： A Burst and Simultaneous Short-Term Pulsed Flux Enhancement from the Magnetar Candidate 1E 1048.1-5937

摘要： 我们报告了于2004年6月29日从异常X射线脉冲星（AXP）1E 1048.1-5937方向探测到的爆发，使用的是 Rossi X射线定时探测器（RXTE）。我们在该爆发尾部发现1E 1048.1-5937的2-10 keV脉冲流量增加了约3.5倍，这表明AXP是此次爆发的起源。这次爆发总体上与2001年从该源方向报告的另两次爆发非常相似。这里明确识别出1E 1048.1-5937为爆发源，也证实了它同样是2001年爆发的起源。爆发峰值的时间非常接近1E 1048.1-5937脉冲峰值的到达时间。爆发表现出显著的光谱演化趋势，从硬能区向软能区变化。在爆发后的11天内，该AXP继续被RXTE、XMM-Newton和Chandra观测。爆发前后的观测未发现宁静态辐射的总流量或光谱有任何变化。比较迄今为止从该源检测到的三次爆发，我们发现此次事件的通量最高（>3.3×10^-8 erg/cm²，在2-20 keV带宽），峰值通量最高（59±9×10^-10 erg/s/cm²，在2-20 keV带宽），并且持续时间最长（>699秒）。爆发的长持续时间将其与典型持续时间为~0.1秒的软伽马重复源（SGR）爆发区分开来。AXP特有的、优先发生在脉冲最大时刻、快速上升且具有较长X射尾（包含大部分总爆发能量）的爆发已被独特地观测到。AXP和SGR爆发之间的显著差异可能为理解这些天体的物理差异提供了新的线索。 显示英文摘要

摘要： We report on the 2004 June 29 burst detected from the direction of the Anomalous X-ray Pulsar (AXP) 1E 1048.1-5937 using the Rossi X-ray Timing Explorer (RXTE). We find a simultaneous increase of ~3.5 times the quiescent value in the 2-10 keV pulsed flux of 1E 1048.1-5937 during the tail of the burst which identifies the AXP as the burst's origin. The burst was overall very similar to the two others reported from the direction of this source in 2001. The unambiguous identification of 1E 1048.1-5937 as the burster here confirms it was the origin of the 2001 bursts as well. The epoch of the burst peak was very close to the arrival time of 1E 1048.1-5937's pulse peak. The burst exhibited significant spectral evolution with the trend going from hard to soft. During the 11 days following the burst, the AXP was observed further with RXTE, XMM-Newton and Chandra. Pre- and post-burst observations revealed no change in the total flux or spectrum of the quiescent emission. Comparing all three bursts detected thus far from this source we find that this event was the most fluent (>3.3x10^-8 erg/cm^2 in the 2-20 keV band), had the highest peak flux (59+/-9x10^-10 erg/s/cm^2 in the 2-20 keV band), and the longest duration (>699 s). The long duration of the burst differentiates it from Soft Gamma Repeater (SGR) bursts which have typical durations of ~0.1 s. Bursts that occur preferentially at pulse maximum, have fast-rises and long X-tails containing the majority of the total burst energy have been seen uniquely from AXPs. The marked differences between AXP and SGRs bursts may provide new clues to help understand the physical differences between these objects.