Spectral and luminosity classification for the cool components in symbiotic stars
文献类型：期刊论文
| 作者 | Zhu, ZX ; Friedjung, M; Zhao, G; Hang, HR; Huang, CC
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| 刊名 | ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES
 |
| 出版日期 | 1999-11-01 |
| 卷号 | 140期号:1页码:69-78 |
| 关键词 | stars : binaries : symbiotic stars : fundamental parameters stars : individual : TX CVn, T CrB, AG Dra infrared : stars |
| ISSN号 | 0365-0138 |
| 英文摘要 | The near infrared spectra of 12 S-type symbiotic stars and 78 comparison stars have been observed with moderate dispersion in five runs from 1992 to 1997, the resolving power being R = lambda/Delta lambda > 2000, with a signal to noise ratio SIN > 100. The triple-headed absorption band of TiO (lambda lambda 8432, 8422 and 8452 Angstrom) emerges when a star is later than M2, and the depth of the TiO absorption band is very sensitive to the spectral type (ST) and insensitive to the luminosity class of the star. We fit a curve of spectral type against the index of the absorption depth of this band with a standard deviation sigma = 0.37 of a subdivision of one spectral type. The IR all triplet (lambda lambda 8498, 8542, 8662 Angstrom); Fe I 8689 Angstrom: and Fe I 8675 Angstrom are good luminosity indicators although the equivalent widths (EWs) of these lines clearly decrease fora star later than M3. When the star is a supergiant the lines have a smaller central residual intensity and broader wings than in the case of a normal giant. The Ca II 8662 Angstrom/Fe I 8675 Pi and Fe I 8689 Angstrom/Fe I 8675 A ratios are also good luminosity indicators for Ii-type giants. The latter is particularly useful when there are abundance anomalies. The metal-poor symbiotic star AG Dra is classified as a Ib or II giant, as is TX CVn, on the basis of Fe I 8689 Angstrom/Fe I 8675 Angstrom. 9 other symbiotic stars containing M-type cool components are classified as giants by direct comparison and quantitative analysis. Due to there being no known good ratio indicator of luminosity for M-type stars in the band studied and because there is no metal abundance data for the symbiotic stars studied by us except for AG Dra, the results for these 9 symbiotic stars are only preliminary. The infrared Ca II triplet of most symbiotic stars clearly varies between the different observing runs. The different luminosity classes given to the same symbiotic star are probably caused by the variability of the lines of ionized elements,: while in some cases they are affected by a low metal abundance. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 学科主题 | Astronomy & Astrophysics |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | ABUNDANCES ; PHOTOMETRY |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000083979500006 |
| 公开日期 | 2013-02-01 |
| 源URL | [http://libir.pmo.ac.cn/handle/332002/8304]  |
| 专题 | 紫金山天文台_南极天文中心 |
| 作者单位 | 1.Acad Sinica, Purple Mt Observ, Nanjing 210008, Peoples R China 2.Inst Astrophys, F-75014 Paris, France 3.Beijing Astron Observ, Beijing 100012, Peoples R China 4.Chinese Acad Sci, Natl Astron Observ, Beijing 100864, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhu, ZX,Friedjung, M,Zhao, G,et al. Spectral and luminosity classification for the cool components in symbiotic stars[J]. ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES,1999,140(1):69-78. |
| APA | Zhu, ZX,Friedjung, M,Zhao, G,Hang, HR,&Huang, CC.(1999).Spectral and luminosity classification for the cool components in symbiotic stars.ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES,140(1),69-78. |
| MLA | Zhu, ZX,et al."Spectral and luminosity classification for the cool components in symbiotic stars".ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES 140.1(1999):69-78. |
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来源：紫金山天文台
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