论文标题
Chandra对行星星云IC 4593的观察结果
Chandra observations of the planetary nebula IC 4593
论文作者
论文摘要
Chandra X射线天文台上的ACIS-S摄像头已用于发现行星星云（PN）IC4593中的热气泡，这是Chandra检测到的最遥远的PN。该数据用于研究IC 4593中X射线发射气体的分布，并估算其物理特性。热气泡的半径〜2 $^{\ prime \ prime} $，被发现限制在IC 4593的光学亮度最内部的空腔内。X射线发射与光学上的含纤维质量大多，温度$ kt \ kt \ kt \ kt \ kt \ kt \ kt \ kt（或大约0.15 $ kev） $T_\mathrm{X}\approx1.7\times10^{6}$ K), electron density $n_\mathrm{e}\approx15$ cm$^{-3}$, and intrinsic X-ray luminosity in the 0.3-1.5 keV energy range $L_\mathrm{X}=3.4\times10^{30}$ erg s $^{ - 1} $。对IC 4593中硬（$ e> $ 0.8 keV）光子的分布的仔细分析表明，从可能与其中心星（CSPN）相关的点源中存在X射线发射。如果是这种情况，则其估计的X射线光度为$ L_ \ MATHRM {X，CSPN} = 7 \ times10^{29} $ erg s $^{ - 1} $，满足log $（l_ \ mathrm {x，cspn}，cspn}/cspn}/l_ \ m m lystry-fine finders fine finders fins fine fine fine fine fins fines fins fins for for for fins for for。 CSPN的X射线检测有助于解释如恒星大气模型所预测的紫外光谱中检测到的高离世物种的存在。
The ACIS-S camera on board the Chandra X-ray Observatory has been used to discover a hot bubble in the planetary nebula (PN) IC4593, the most distant PN detected by Chandra so far. The data are used to study the distribution of the X-ray-emitting gas in IC 4593 and to estimate its physical properties. The hot bubble has a radius of ~2$^{\prime\prime}$ and is found to be confined inside the optically-bright innermost cavity of IC 4593. The X-ray emission is mostly consistent with that of an optically-thin plasma with temperature $kT\approx0.15$ keV (or $T_\mathrm{X}\approx1.7\times10^{6}$ K), electron density $n_\mathrm{e}\approx15$ cm$^{-3}$, and intrinsic X-ray luminosity in the 0.3-1.5 keV energy range $L_\mathrm{X}=3.4\times10^{30}$ erg s$^{-1}$. A careful analysis of the distribution of hard ($E>$0.8 keV) photons in IC 4593 suggests the presence of X-ray emission from a point source likely associated with its central star (CSPN). If this were the case, its estimated X-ray luminosity would be $L_\mathrm{X,CSPN}=7\times10^{29}$ erg s$^{-1}$, fulfilling the log$(L_\mathrm{X,CSPN}/L_\mathrm{bol})\approx-7$ relation for self-shocking winds in hot stars. The X-ray detection of the CSPN helps explain the presence of high-ionisation species detected in the UV spectra as predicted by stellar atmosphere models.
