| Imaging spectropolarimetry of Ti I 2231 nm in a sunspot | |
Penn, MJ1,2; Cao WD(曹文达)3,4 ; Walton, SR2; Chapman, GA1; Livingston, W1; Penn, MJ (reprint author), Natl Opt Astron Observ, Natl Solar Observ, 950 N Cherry Ave, Tucson, AZ 85719 USA.
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| 发表期刊 | SOLAR PHYSICS
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| 2003-07 | |
| 卷号 | 215期号:1页码:87-97 |
| DOI | 10.1023/A:1024858706915 |
| 产权排序 | 第3完成单位 |
| 收录类别 | SCI |
| 摘要 | Spectro-polarimetric observations at 2231 nm were made of NOAA 10008 near the west solar limb on 29 June 2002 using the National Solar Observatory McMath-Pierce Telescope at Kitt Peak and the California State University Northridge - National Solar Observatory infrared camera. Scans of spectra in both Stokes I and Stokes V were collected; the intensity spectra were processed to remove strong telluric absorption lines, and the Stokes V umbral spectra were corrected for instrumental polarization. The sunspot temperature is computed using the continuum contrast and umbral temperatures down to about 3700 K are observed. A strong Ti I line at 2231.0 nm is used to probe the magnetic and velocity fields in the spot umbra and penumbra. Measurements of the Ti I equivalent width versus plasma temperature in the sunspot agree with model predictions. Zeeman splitting measurements of the Stokes I and Stokes V profiles show magnetic fields up to 3300 G in the umbra, and a dependence of the magnetic field on the plasma temperature similar to that which was seen using Fe I 1565 nm observations of the same spot two days earlier. The umbral Doppler velocity measurements are averaged in 16 azimuthal bins, and no radial flows are revealed to a limit of +/- 200 m s(-1). A Stokes V magnetogram shows a reversal of the line-of-sight magnetic component between the limb and disk center sides of the penumbra. Because the Ti I line is weak in the penumbra, individual spectra are averaged in azimuthal bins over the entire penumbral radial extent. The averaged Stokes V spectra show a magnetic reversal as a function of sunspot azimuthal angle. The mean penumbral magnetic field as measured with the Stokes V Zeeman component splitting is 1400 G. Several weak spectral lines are observed in the sunspot and the variation of the equivalent width versus temperature for four lines is examined. If these lines are from molecules, it is possible that lines at 2230.67, 2230.77, and 2231.70 nm originate from OH, while the line at 2232.21 nm may originate from CN. |
| 语种 | 英语 |
| 学科领域 | Astronomy & Astrophysics |
| 文章类型 | Article |
| ISSN | 0038-0938 |
| URL | 查看原文 |
| WOS记录号 | WOS:000184251900006 |
| WOS研究方向 | Astronomy & Astrophysics |
| WOS类目 | Astronomy & Astrophysics |
| 关键词[WOS] | SOLAR MAGNETIC FEATURES ; INFRARED LINES ; TEMPERATURE ; PROBES ; FIELD ; COOL |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.ynao.ac.cn/handle/114a53/4159 |
| 专题 | 其他 |
| 通讯作者 | Penn, MJ (reprint author), Natl Opt Astron Observ, Natl Solar Observ, 950 N Cherry Ave, Tucson, AZ 85719 USA. |
| 作者单位 | 1.National Solar Observatory, 950 N Cherry Av, Tucson, AZ , 85719, U.S.A 2.Department of Physics and Astronomy, California State University Northridge, 18111 Nordhoff St, Northridge, CA, 91330-8268, U.S.A 3.National Astronomical Observatories, CAS, Yunnan Observatory, PO Box 110 4.Center for Solar Research, New Jersey Institute of Technology, 323 Martin Luther King Blvd, Newark, NJ, 07102, U.S.A |
| 推荐引用方式 GB/T 7714 | Penn, MJ,Cao WD,Walton, SR,et al. Imaging spectropolarimetry of Ti I 2231 nm in a sunspot[J]. SOLAR PHYSICS,2003,215(1):87-97. |
| APA | Penn, MJ,Cao WD,Walton, SR,Chapman, GA,Livingston, W,&Penn, MJ .(2003).Imaging spectropolarimetry of Ti I 2231 nm in a sunspot.SOLAR PHYSICS,215(1),87-97. |
| MLA | Penn, MJ,et al."Imaging spectropolarimetry of Ti I 2231 nm in a sunspot".SOLAR PHYSICS 215.1(2003):87-97. |
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| Imaging Spectropolar（211KB） | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | 浏览 请求全文 | |
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