Zhang, Jinge;
Reid, Hamish AS;
Krupar, Vratislav;
Zucca, Pietro;
Dabrowski, Bartosz;
Krankowski, Andrzej;
(2023)
Deriving Large Coronal Magnetic Loop Parameters Using LOFAR J Burst Observations.
Solar Physics
, 298
(1)
, Article 7. 10.1007/s11207-022-02096-0.
Preview |
Text
s11207-022-02096-0.pdf - Published Version Download (1MB) | Preview |
Abstract
Large coronal loops around one solar radius in altitude are an important connection between the solar wind and the low solar corona. However, their plasma properties are ill-defined, as standard X-ray and UV techniques are not suited to these low-density environments. Diagnostics from type J solar radio bursts at frequencies above 10 MHz are ideally suited to understand these coronal loops. Despite this, J-bursts are less frequently studied than their type III cousins, in part because the curvature of the coronal loop makes them unsuited for using standard coronal density models. We used LOw-Frequency-ARray (LOFAR) and Parker Solar Probe (PSP) solar radio dynamic spectrum to identify 27 type III bursts and 27 J-bursts during a solar radio noise storm observed on 10 April 2019. We found that their exciter velocities were similar, implying a common acceleration region that injects electrons along open and closed magnetic structures. We describe a novel technique to estimate the density model in coronal loops from J-burst dynamic spectra, finding typical loop apex altitudes around 1.3 solar radius. At this altitude, the average scale heights were 0.36 solar radius, the average temperature was around 1 MK, the average pressure was 0.7mdyncm−2, and the average minimum magnetic field strength was 0.13 G. We discuss how these parameters compare with much smaller coronal loops.
| Type: | Article |
|---|---|
| Title: | Deriving Large Coronal Magnetic Loop Parameters Using LOFAR J Burst Observations |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/s11207-022-02096-0 |
| Publisher version: | https://doi.org/10.1007/s11207-022-02096-0 |
| Language: | English |
| Additional information: | Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, Energetic particles, Electrons, Magnetic fields, Corona, Radio emission, Radio bursts, SOLAR RADIO-BURSTS, ELECTRON ACCELERATION |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10164461 |
Archive Staff Only
 |
View Item |
