论文标题
灾难性变量中的白矮人光时丰度-II。带有和没有口罩的白色矮人
White Dwarf Photospheric Abundances in Cataclysmic Variables -- II. White Dwarfs With and Without a Mask
论文作者
论文摘要
利用现在可用的GAIA EDR3视差，我们进行了档案{\ it Hubble Space望远镜}（HST）对10个灾难性变量系统的远紫外线光谱分析，包括5个精心挑选的封闭系统。我们获得了准确的白矮人（WD）质量和温度，与4种黯然失色的系统非常吻合。对于样本中的三个系统，即BD PAV，HS 2214和TT CRT，我们报告了其WDS的第一个健壮质量。我们建模了吸收系，以得出十个系统中每个系统的WD化学丰度和旋转速度。如预期的那样，对于五个较高的倾斜度（$ i \ gtrsim 75^{\ circ} $）系统，随着将冷吸收板（用$ n _ {\ rm h} \ rm h}^{20} {20} {20} -10} -10^{22} $ cm $ cm $ cm $ cm cm} $ n _ _ {\ rm h}} $ n _ _ {\ rm h}^$ cm^} $ n _ {\ rm h}^= 2}的模型得到改善。 HST光谱中金属线的建模表明，这10个系统中有7个具有明显的碳丰度，而6个具有硅的硅丰度，从而提供了进一步的证据，表明CV WDS表现出碳和硅的亚层丰富度。我们建议，在某些CV WD（例如IR com）的光谱中，强铝吸收线（和铁吸收特征）可能是由于存在{\ it Thin}铁幕（$ n _ {\ rm h} \ rm h} \ 10^{19} {19} $ cm $ cm $^{-2} $，而不是to photoseance and to photy to phosecans and sumulum and and and and and and and and of to and of to nod and of to nod of to and of to and of to and of to nod and of to nof word and。派生的WD（投影）旋转速度均在$ \ $ \ \ \ 100-400 $〜km/s的范围内，所有的亚算法都与早期研究中获得的值相似。
Taking advantage of the now available Gaia EDR3 parallaxes, we carry out an archival {\it Hubble Space Telescope} (HST) far ultraviolet spectroscopic analysis of 10 cataclysmic variable systems, including 5 carefully selected eclipsing systems. We obtain accurate white dwarf (WD) masses and temperatures, in excellent agreement with the masses for 4 of the eclipsing systems. For three systems in our sample, BD Pav, HS 2214, and TT Crt, we report the first robust masses for their WDs. We modeled the absorption lines to derive the WD chemical abundances and rotational velocities for each of the ten systems. As expected, for five higher inclination ($i \gtrsim 75^{\circ}$) systems, the model fits are improved with the inclusion of a cold absorbing slab (an iron curtain masking the WD) with $N_{\rm H} \approx 10^{20}-10^{22}$cm$^{-2}$. Modeling of the metal lines in the HST spectra reveals that 7 of the 10 systems have significant subsolar carbon abundance, and six have subsolar silicon abundance, thereby providing further evidence that CV WDs exhibit subsolar abundances of carbon and silicon. We suggest that strong aluminum absorption lines (and iron absorption features) in the spectra of some CV WDs (such as IR Com) may be due to the presence of a {\it thin} iron curtain ($N_{\rm H}\approx 10^{19}$cm$^{-2}$) rather than to suprasolar aluminum and iron abundances in the WD photosphere. The derived WD (projected) rotational velocities all fall in the range $\approx 100-400$~km/s, all sub-Keplerian similar to the values obtained in earlier studies.
