The Slow X-Ray Expansion of the Northwestern Rim of the Supernova Remnant RX J0852.0–4622
The Slow X-Ray Expansion of the Northwestern Rim of the Supernova Remnant RX J0852.0–4622
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DOI：
10.1086/588499
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发表时间：
2008-03
期刊：
影响因子：
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通讯作者：
S. Katsuda;H. Tsunemi;K. Mori
中科院分区：
文献类型：
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作者：
S. Katsuda;H. Tsunemi;K. Mori
44Ti的放射性衰变线的探测提供了独特的证据，证明γ射线源是一个年轻的（<1000年）超新星遗迹，因为44Ti的寿命很短，只有~90年。迄今为止，只有仙后座a和RX J0852.0-4622两个银河系遗迹被报道为44Ti线的发射器，尽管后者的探测一直存在争议。本文报道了RX J0852.0-4622西北边缘的膨胀测量结果，其膨胀率为0.023%±0.006%，比历史上年轻残余物的膨胀率低约5倍。如此缓慢的膨胀表明RX J0852.0-4622并不像预期的那样年轻。我们估计这个遗迹的年龄在1700-4300年之间，这取决于它的进化阶段。假设由非热x射线辐射检测得出的~3000 km s−1的高激波速度，我们也推导出了~750 pc到这个残余物的距离。
The detection of the radioactive decay line of 44Ti provides unique evidence that the γ-ray source is a young (<1000 yr) supernova remnant because of the short 44Ti lifetime of ~90 yr. Only two Galactic remnants, Cassiopeia A and RX J0852.0–4622, have hitherto been reported as 44Ti line emitters, although the detection from the latter has been debated. Here we report on an expansion measurement of the northwestern rim of RX J0852.0–4622 obtained with X-ray observations separated by 6.5 yr. The expansion rate is derived to be 0.023% ± 0.006%, which is about 5 times lower than those of young historical remnants. Such a slow expansion suggests that RX J0852.0–4622 is not as young a remnant as has been expected. We estimate an age of 1700-4300 yr for this remnant, depending on its evolutionary stage. Assuming a high shock speed of ~3000 km s−1, which is suggested by the detection of nonthermal X-ray radiation, the distance of ~750 pc to this remnant is also derived.