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Issue A&A Volume 415, Number 3, March I 2004 Page(s) 1133 - 1139 Section The Sun DOI 10.1051/0004-6361:20034234

A&A 415, 1133-1139 (2004)
DOI: 10.1051/0004-6361:20034234

On the widths of the Mg X lines near 60 nm in the corona

K. Wilhelm¹, B. N. Dwivedi^{1, 2} and L. Teriaca<sup>1

1</sup>  Max-Planck-Institut für Aeronomie, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany
²  Department of Applied Physics, Banaras Hindu University, Varanasi-221005, India

(Received 27 August 2003 / Accepted 3 November 2003)

Abstract
We examine the line widths of both components of the Mg X doublet at 60.98 nm and 62.50 nm in the low corona of the quiet Sun, and find that the Doppler width (i.e. half 1/e width) broadens from  pm to 9.5 pm (with an estimated relative standard uncertainty of 4%) between the limb and 220 Mm above the limb in the equatorial corona. In a polar coronal hole, the Doppler width increases from 10.8 pm near 30 Mm to 11.4 pm at around 80 Mm. The analysis does not provide any evidence for a narrowing of the emission-line profiles as a function of the distance from the solar limb.

Key words: Sun: corona -- Sun: UV radiation

Offprint request: K. Wilhelm, wilhelm@linmpi.mpg.de

© ESO 2004

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