XMM-Newton Observations of G32.45+0.1 and G38.55+0.0: Diffuse Hard X-Ray Sources Found by the ASCA Galactic Plane Survey
XMM-Newton Observations of G32.45+0.1 and G38.55+0.0: Diffuse Hard X-Ray Sources Found by the ASCA Galactic Plane Survey
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DOI：
10.1093/pasj/56.6.1059
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发表时间：
2004-10
影响因子：
2.3
通讯作者：
H. Yamaguchi;M. Ueno;K. Koyama;A. Bamba;S. Yamauchi
中科院分区：
文献类型：
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作者：
H. Yamaguchi;M. Ueno;K. Koyama;A. Bamba;S. Yamauchi
我们报道了G32.45+0.1和G38.55+0.0的XMM-牛顿观测。这些是由ASCA银河平面勘测发现的扩散硬X射线源，但ASCA有限的空间分辨率不能确定这些是真正的扩散源还是一组未分辨的点源。用比ASCA更高的空间分辨率证实了G32.45+0.1具有弥散的壳状结构，半径为∼4�。光谱显示无特征的连续谱，可以用Γ∼2.2的幂定律模型来拟合，其吸收为NH∼5.2×10 2 2 cm−2。从这个NH值，我们估计到G32.45+0.1的距离为∼17kpc。因此，壳层的光度(在0.5-10.0keV波段)和半径分别为∼9.5×1034ergss−1和∼20pc。NRAO/VLA巡天(NVSS；1.4 GHz)中的射电复合源与G32.45+0.1的X射线壳层有全球联系。因此，G32.45+0.1很可能是一个同步加速器主导的壳状SNR。在另一个ASCA漫反射源G38.55+0.0的XMM-牛顿图像中没有发现明显的弥漫结构。观测到的通量上限(0.5keV~10.0keV)估计为9.0×10~(-10)−~(13)Ergscm−~2 S−~(1)
We report on XMM-Newton observations of G32.45+0.1 and G38.55+0.0. These were discovered as diffuse hard X-ray sources by the ASCA Galactic Plane Survey, but the limited spatial resolution of ASCA could not conclude whether these are truly diffuse or a group of unresolved point-sources. XMM-Newton, with higher spatial resolution than ASCA, confirmed that G32.45+0.1 has a diffuse shell-like structure with a radius of ∼ 4 � .T he spectrum shows a featureless continuum, and can thus be fitted by a power-law model of Γ ∼ 2.2 with an absorption of NH ∼ 5.2 ×10 22 cm −2 .F rom thisNH value, we estimated the distance to G32.45+0.1 to be ∼ 17kpc. Thus, the luminosity (in the 0.5–10.0keV band) and radius of the shell are ∼ 9.5 ×10 34 ergss −1 and ∼ 20pc, respectively. The radio complex sources in the NRAO/VLA Sky Survey (NVSS; 1.4GHz) are globally associated with the X-ray shell of G32.45+0.1. Therefore, G32.45+0.1 is likely to be a synchrotron-dominant shell-like SNR. No significant diffuse structure was found in the XMM-Newton image of another ASCA diffuse source, G38.55+0.0. The upper limit of the observed flux (0.5–10.0keV) is estimated to be 9.0 ×10 −13 ergscm −2 s −1 , which is consistent with the