Coronal composition above the solar equator and the north pole as determined from spectra acquired by the SUMER instrument on Soho

被引：130

作者：

Feldman, U

Schühle, U

Widing, KG

Laming, JM

机构：

[1] USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA

[2] Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany

[3] SFA Inc, Largo, MD 20774 USA

来源：

ASTROPHYSICAL JOURNAL | 1998年 / 505卷 / 02期

关键词：

Sun : abundances; Sun : corona;

D O I：

10.1086/306195

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Using spectra obtained by the SUMER instrument on the Solar and Heliospheric Observatory (SONO) we have determined the composition of the bulk of the coronal plasma in the vicinity of the solar surface over a polar coronal hole and an equatorial region. Our measurements show that although low first ionization potential (FIP) elements are enriched by about a factor of 4 in the corona above the quiet equatorial region, little or no enrichment exists above the north polar coronal hole. These observations are in good agreement with the Ulysses in situ observations in both fast speed and slow speed winds.

引用

页码：999 / 1006

页数：8

共 42 条

[21] Electron density diagnostics for the solar upper atmosphere from spectra obtained by SUMER/SOHO [J].