论文标题
在超新星残留N49的X射线光栅光谱中共振散射的证据
Evidence for Resonance Scattering in the X-ray Grating Spectrum of the Supernova Remnant N49
论文作者
论文摘要
共振散射（RS）是天文对象的重要过程，因为它会影响元素丰度的测量并扭曲对象的表面亮度。可以预测，RS可能发生在超新星残留物（SNR）的等离子体中。尽管有几位作者报告了SNR中RS的提示，但迄今为止尚未确定强大的观察证据。我们在XMM-Newton上使用反射光谱仪对SNR N49进行高分辨率X射线光谱。 N49的RGS频谱显示出$ vii he $α$线的G-RATIO以及O VIII $β$/$α$和Fe XVII（3S-2P）/（3D-2P）的比例，这是由薄热等离子体的发射所无法解释的。这些线比可以通过Rs的效果很好地解释。我们的结果意味着RS对氧气丰度的测量具有很大的影响。
Resonance scattering (RS) is an important process in astronomical objects, because it affects measurements of elemental abundances and distorts surface brightness of the object. It is predicted that RS can occur in plasmas of supernova remnants (SNRs). Although several authors reported hints of RS in SNRs, no strong observational evidence has been established so far. We perform a high-resolution X-ray spectroscopy of the SNR N49 with the Reflection Grating Spectrometer aboard XMM-Newton. The RGS spectrum of N49 shows a high G-ratio of O VII He$α$ lines as well as O VIII Ly$β$/$α$ and Fe XVII (3s-2p)/(3d-2p) ratios which cannot be explained by the emission from a thin thermal plasma. These line ratios can be well explained by the effect of RS. Our result implies that RS has a large impact particularly on a measurement of the oxygen abundance.
