Jump to ContentJump to Main Navigation
Show Summary Details
More options …

Open Astronomy

formerly Baltic Astronomy

Editor-in-Chief: Barbuy, Beatriz

IMPACT FACTOR 2018: 0.350

CiteScore 2018: 0.24

SCImago Journal Rank (SJR) 2018: 0.202
Source Normalized Impact per Paper (SNIP) 2018: 0.144

ICV 2018: 120.66

Open Access
See all formats and pricing
More options …
Volume 25, Issue 2


Depressed Emission between Magnetic Arcades near a Sunspot

B. I. Ryabov / K. Shibasaki
Published Online: 2017-02-01 | DOI: https://doi.org/10.1515/astro-2017-0124


The locations of the depressed emission in microwaves, EUV and soft X-rays are compared with each other and with the location of the plasma outflow in the active region (AR) 8535 on the Sun. We found that two open-field regions overlap the regions of depressed emission near the AR's sunspot. These two open-field regions are simulated with the potential-field source-surface (PFSS) model under radial distances of RSS = 1.8 R and RSS = 2.5 R. Each open-field region is located between the arcades of the loops of the same magnetic polarity. The former open-field region covers the region of the plasma outflow, which is thus useful for the tests on connection to the heliosphere. The utmost microwave depression of the intensity in the ordinary mode (the Very Large Array 15 GHz observations) also overlaps the region of the plasma outflow and thus indicates this outflow. The lasting for eight days depression in soft X-rays and the SOHO EIT 2.84×10−8 m images are attributed to the evacuation of as hot coronal plasma as T ≥ 2 × 106 K from the extended in height (“open”) magnetic structures. We conclude that the AR 8535 presents the sunspot atmosphere affected by the large-scale magnetic fields.

Keywords: Sun: sunspots; radio radiation; EUV; X-rays; magnetic fields


About the article

Received: 2016-02-15

Accepted: 2016-04-21

Published Online: 2017-02-01

Published in Print: 2016-06-01

Citation Information: Open Astronomy, Volume 25, Issue 2, Pages 225–235, ISSN (Online) 2543-6376, DOI: https://doi.org/10.1515/astro-2017-0124.

Export Citation

© 2016 B. I. Ryabov et al., published by De Gruyter Open. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. BY-NC-ND 3.0

Citing Articles

Here you can find all Crossref-listed publications in which this article is cited. If you would like to receive automatic email messages as soon as this article is cited in other publications, simply activate the “Citation Alert” on the top of this page.

B. I. Ryabov and A. Vrublevskis
Solar Physics, 2020, Volume 295, Number 1

Comments (0)

Please log in or register to comment.
Log in