当前位置: X-MOL 学术Astron. Lett. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
High-Resolution Optical Spectroscopy of the Post-AGB Supergiant V340 Ser ( $${\mathbf{=}}$$ IRAS 17279 $$\mathbf{-}$$ 1119)
Astronomy Letters ( IF 0.9 ) Pub Date : 2020-11-22 , DOI: 10.1134/s1063773720080010
V. G. Klochkova , V. E. Panchuk , N. S. Tavolzhanskaya , M. V. Yushkin

Abstract

Evidence of wind variability and velocity stratification in the extended atmosphere has been found in the spectra of the supergiant V340 Ser (\({=}\)IRAS 17279\(-\)1119) taken at the 6-m BTA telescope with a resolution \(R\geq 60\,000\). The H\(\alpha\) line has a P Cyg profile whose absorption component (\(V_{\odot}={+}34\) km s\({}^{-1}\)) is formed in the upper layers of the expanding atmosphere close the circumstellar medium. For four dates the mean velocity has been derived from the positions of 300–550 symmetric metal absorptions with an accuracy better than \({\pm}0.1\) km s\({}^{-1}\): \(V_{\odot}=59.30\), \(60.09\), \(58.46\), and \(55.78\) km s\({}^{-1}\). A lot of low-excitation metal lines have an inverse P Cyg profile. The mean positions of their emission components, \(V_{\odot}=46.3\pm 0.4\) km s\({}^{-1}\), differ systematically from the velocity inferred from symmetric absorptions, suggesting the presence of a velocity gradient in the supergiant’s extended atmosphere. The multicomponent profile of the Na I D lines contains the interstellar, \(V_{\odot}={-}11.2\) km s\({}^{-1}\), and circumstellar, \(V_{\odot}={+}10\) km s\({}^{-1}\), components and the component forming in the upper atmospheric layers, \(V_{\odot}={+}34.0\) km s\({}^{-1}\). The mean velocity from 20–30 diffuse interstellar bands (DIBs) identified in the spectra, \(V_{\odot}\textrm{(DIBs)}={-}11.6\pm 0.2\) km s\({}^{-1}\), agrees with the velocity from interstellar Na I and K I components. The equivalent width of the oxygen triplet \(\textrm{W(O\,I 7774)}=1.25\) Å corresponds to an absolute magnitude of the star \(Mv\approx{-}4.6^{m}\), which, given the total (interstellar \(+\) circumstellar) extinction, leads to a distance to the star \(d\approx 2.3\) kpc.



中文翻译:

AGB后Supergiant V340 Ser的高分辨率光谱($$ {\ mathbf {=}} $$ IRAS 17279 $$ \ mathbf {-} $$ 1119)

摘要

在6米BTA望远镜拍摄的超大型V340 Ser(\({=} \) IRAS 17279 \(-\) 1119)光谱中发现了扩展大气中风的可变性和速度分层的证据\(R \ geq 60 \,000 \)。H \(\ alpha \)线具有P Cyg轮廓,其吸收分量(\(V _ {\ odot} = {+} 34 \) km s \({} ^ {-1} \))形成于不断膨胀的大气层的上层封闭了星际介质。对于四个日期,平均速度是从300–550个对称金属吸收的位置得出的,其精度优于\({\ pm} 0.1 \) km s \({} ^ {-1} \)\(V_ {\ odot} = 59.30 \)\(60.09 \)\(58.46 \)\(55.78 \) km s \({} ^ {-1} \)。许多低激励金属线具有反向的P Cyg轮廓。它们的发射分量的平均位置\(V _ {\ odot} = 46.3 \ pm 0.4 \) km s \({} ^ {-1} \)与对称吸收推断的速度系统地不同,这表明存在在超巨星的扩展大气中的速度梯度。Na ID线的多分量轮廓包含星际\(V _ {\ odot} = {-} 11.2 \) km s \({} ^ {-1} \)和星际\(V _ {\ odot} = {+} 10 \) km s \({} ^ {-1} \),成分和在高层大气层中形成的成分\(V _ {\ odot} = {+} 34.0 \) km s \({} ^ {-1} \)。频谱中确定的20–30个星际漫射带(DIB)的平均速度\(V _ {\ odot} \ textrm {(DIBs)} = {-} 11.6 \ pm 0.2 \) km s \({} ^ { -1} \),与来自星际Na I和K I分量的速度一致。氧三重态的等效宽度\(\ textrm {W(O \,I 7774)} = 1.25 \) Å对应于恒星的绝对大小\(Mv \ approx {-} 4.6 ^ {m} \),给定总(星际\(+ \)绕星)灭绝,导致到恒星的距离(\ d \约2.3 \) kpc。

更新日期:2020-11-22
down
wechat
bug