English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present an analysis of several Hinode EIS observations of coronal linewidths in the quiet Sun, up to 1.5 Rsun radial distances. No significantvariations are found, which indicates no damping of Alfv\'en waves in thequiescent corona.  However, the uncertainties in estimating the instrumental width mean that afirm conclusion cannot be reached. We present a discussion of various EISinstrumental issues and suggest that the strongest lines, from Fe XII at 193.5and 195.1 A, have anomalous instrumental widths. We show how line widths in EISare uncertain when the signal is low, and that the instrumental variation alongthe slit is also uncertain. We also found an anomalous decrease (up to 40%) inthe intensities of these lines in many off-limb and active region observations,and suggest that this is due to opacity effects. We find that the most reliablemeasurements are obtained from the weaker lines.

Hinode EIS line widths in the quiet corona up to 1.5 Rsun