Diagnostics of Flare Loop Parameters in Shrinkage and Ascent Stages Using Radio, X-ray, and UV Emission
Abstract
:1. Introduction
2. Loop Shrinkage in Terms of an Equivalent Electric Circuit
3. An Oscillating Loop as an Equivalent RLC Circuit
4. Dynamics of Flare Loop Parameters Inferred from Multi-Wavelength Observations
4.1. Loop in the Flare on 24 August 2002
- (i)
- In the shrinking phase (00:53–01:02 UT), an increase in the plasma temperature by more than a factor of 2.5 is observed, as well as an increase in the plasma density in the loop, approximately by a factor of three. These changes in the parameters are accompanied by a relative increase in the electric current , approximately by the factor of 1.48.
- (ii)
- At the stage of loop ascent (01:02–01:10 UT), accompanied by relatively small oscillations at 17 and 35 GHz, the plasma density inside the loop continues to increase approximately by a factor of 1.6, and the temperature decreases from 27.6 MK to 17.7 MK. Therefore, the above estimate of the magnitude of the electric current (14) reflects a certain average value at the stage of the loop expansion because the parameters that determine the period of oscillations: plasma density and the electric current magnitude, change during oscillations.
- (iii)
- The total electric current of about 1011 A contained a flare loop with r = 3.5 × 106 m means a current density of j ≈ 10−2 Am−2. This value agrees with estimates of the density of the vertical electric current found using the vector magnetograms (e.g., [21,22]). In more powerful flares, the value of j can be an order of magnitude larger.
4.2. Loop in the Flare on 16 April 2002
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
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Flare Phase | /109 cm | R/10−2 | EM/1049 cm−3 | V/1027 cm3 | T MK | n/1010 cm−3 | I/1010 A |
---|---|---|---|---|---|---|---|
Flare start 00:49 UT | 2.3 | 7.0 | 0.38 | 2.80 | 9.4 | 3.70 | - |
Shrink start 00:53 UT | 2.3 | 13.3 | 0.78 | 2.80 | 11.0 | 5.28 | 8.6 |
Shrink end 01:02 UT | 1.6 | 50.0 | 5.2 | 1.93 | 27.6 | 16.4 | 12.7 |
Oscillations 01:00–01:10 UT | 2.45 | 31.7 | 22.0 | 2.96 | 17.7 | 27.0 | 15.9 |
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Zaitsev, V.; Stepanov, A. Diagnostics of Flare Loop Parameters in Shrinkage and Ascent Stages Using Radio, X-ray, and UV Emission. Universe 2023, 9, 261. https://doi.org/10.3390/universe9060261
Zaitsev V, Stepanov A. Diagnostics of Flare Loop Parameters in Shrinkage and Ascent Stages Using Radio, X-ray, and UV Emission. Universe. 2023; 9(6):261. https://doi.org/10.3390/universe9060261
Chicago/Turabian StyleZaitsev, Valery, and Alexander Stepanov. 2023. "Diagnostics of Flare Loop Parameters in Shrinkage and Ascent Stages Using Radio, X-ray, and UV Emission" Universe 9, no. 6: 261. https://doi.org/10.3390/universe9060261