论文标题
恒星光谱中TIO同位素学的分析
Analysis of the TiO isotopologues in stellar optical spectra
论文作者
论文摘要
这项研究基于使用新的Exomol Tio rovibronin Lines列表来识别和建模M-dwarfs光谱中的TIO同位素学特征。 我们的目的是通过对晚期型星的光谱进行建模并确定其Ti同位素丰度，以比较使用不同作者的行列表计算的TIO同位素光谱来研究涉及TIO不同同位素的电子带的计算的问题。 我们将理论合成光谱拟合到观察到的TIO的恒星分子带。我们对两个M少量的光谱进行建模：GJ 15A（M1V）和GJ 15B（M3 V），以确定其大气中的Ti同位素比。 我们演示了TIO差异化的Exomol {\ sc Toto}行列表的准确性，以及确定光谱范围内精确的Ti同位素丰度的可能性。 7580--7594Å的光谱范围似乎特别有用，有两个原子线路和$^{50} ti $ O，$^{49} ti $ O，$^{49} ti $ o，$^{48} ti $ o，$^{48} ti $ o，$^{47} ti $ o在我们的两种M-dwarf中清楚地观察到。 We determine non-solar Ti isotopic ratios of $^{46}Ti$ : $^{47}Ti$ : $^{48}Ti$ : $^{49}Ti$ : $^{50}Ti$ = 7.9 : 5.2 : 72.8 : 7.9 :6.2 for GJ 15A and 7.4 : 4.2 : 76.6 : 5.8 : 6.0 for GJ 15B with accuracy订单$ \ pm $ 0.2。 [Ti] = 0.040和0.199在准确性$ \ pm $ 0.10中也分别确定了GJ 15A和GJ 15B。 我们发现exomol {\ sc toto} tio行列表：a）比其他可用的TIO线列表更好地描述了线路位置的细节和M-Dwarf光谱的强度； b）正确地重现在M-warf光谱中观察到的TIO同位素学带的位置和强度； c）可用于确定M-Star大气中的Ti同位素丰度。
This study is based on the use of the new ExoMol TiO rovibronic line lists to identify and model TiO isotopologue features in spectra of M-dwarfs. We aim to investigate problems involving the computation of electronic bands for different isotopologues of TiO by modelling optical spectra of late-type stars and to determine their Ti isotopic abundances, to compare the TiO isotopologues spectra computed using line lists by different authors. We fit theoretical synthetic spectra to the observed stellar molecular bands of TiO. We model spectra of two M-dwarfs: GJ 15A (M1V) and GJ 15B (M3 V) to determine Ti isotopic ratios in their atmospheres. We demonstrate the accuracy of the ExoMol {\sc Toto} line list for differentisotopologues of TiO and the possibility of determining accurate Ti isotope abundances in a numberof spectral ranges. The 7580--7594 Å spectral range seems particularly useful, with two atomic linesof Fe I and molecular band heads of $^{50}Ti$O, $^{49}Ti$O, $^{48}Ti$O, $^{47}Ti$O clearly observable in our two M-dwarf spectra. We determine non-solar Ti isotopic ratios of $^{46}Ti$ : $^{47}Ti$ : $^{48}Ti$ : $^{49}Ti$ : $^{50}Ti$ = 7.9 : 5.2 : 72.8 : 7.9 :6.2 for GJ 15A and 7.4 : 4.2 : 76.6 : 5.8 : 6.0 for GJ 15B with accuracy of order $\pm$ 0.2. [Ti] = 0.040 and 0.199 within accuracy $\pm$ 0.10 were also determined for GJ 15A and GJ 15B, respectively. We find that the ExoMol {\sc Toto} TiO line list: a) describes the fine details in line position and intensities of the M-dwarf spectra better than other available TiO line lists; b) correctly reproduces the positions and intensities of the TiO isotopologue band heads observed in M-dwarf spectra; c) can be used to determine Ti isotope abundances in atmospheres of M-stars.
