| Issue |
A&A
Volume 598, February 2017
|
|
|---|---|---|
| Article Number | A89 | |
| Number of page(s) | 38 | |
| Section | The Sun | |
| DOI | https://doi.org/10.1051/0004-6361/201629238 | |
| Published online | 09 February 2017 | |
Solar H-alpha features with hot onsets⋆,⋆⋆
III. Long fibrils in Lyman-alpha and with ALMA
1 Lingezicht Astrophysics, ’t Oosteneind 9, 4158 CA Deil, The Netherlands
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
2 National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, 181-8588 Tokyo, Japan
Received: 4 July 2016
Accepted: 4 October 2016
Abstract
In H-alpha most of the solar surface is covered by dense canopies of long opaque fibrils, but predictions for quiet-Sun observations with ALMA have ignored this fact. Comparison with Ly-alpha suggests that the extraordinary opacity of H-alpha fibrils is caused by hot precursor events. Application of a recipe that assumes momentary Saha-Boltzmann extinction during their hot onset to millimeter wavelengths suggests that ALMA will observe H-alpha-like fibril canopies, not acoustic shocks underneath, and will yield data more interesting than if these canopies were transparent.
Key words: Sun: chromosphere / Sun: infrared
An additional file is available at the end of the PDF file of this article.
This study is offered as compliment to M.W.M. de Graauw. Our ways, objects, instruments and spectral domains parted after the 1970 eclipse but converge here.
© ESO, 2017
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.