Doppler Signature of a Possible Termination Shock in an Off-Limb Solar Flare
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2024
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866913225561341952 |
|---|---|
| author | French, Ryan J. Yu, Sijie Chen, Bin Shen, Chengcai Matthews, Sarah A. |
| author_facet | French, Ryan J. Yu, Sijie Chen, Bin Shen, Chengcai Matthews, Sarah A. |
| contents | We report striking Doppler velocity gradients observed during the well-observed September 10th 2017 solar flare, and argue that they are consistent with the presence of an above-the-looptop termination shock beneath the flare current sheet. Observations from the Hinode Extreme-ultraviolet Imaging Spectrometer (EIS) measure plasma sheet Doppler shifts up to 35 km/s during the late-phase of the event. By comparing these line-of-sight flows with plane-of-sky measurements, we calculate total velocity downflows of 200+ km/s, orientated 6-10° out of the plane of sky. The observed velocities drop rapidly at the base of the hot plasma sheet seen in extreme ultraviolet, consistent with simulated velocity profiles predicted by our 2.5D magnetohydrodynamics model that features a termination shock at the same location. Finally, the striking velocity deceleration aligns spatially with the suppression of Fe XXIV non-thermal velocities, and a 35--50 keV hard X-ray looptop source observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Together, these observations are consistent with the presence of a possible termination shock within the X8.2-class solar flare. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2402_04445 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Doppler Signature of a Possible Termination Shock in an Off-Limb Solar Flare French, Ryan J. Yu, Sijie Chen, Bin Shen, Chengcai Matthews, Sarah A. Solar and Stellar Astrophysics High Energy Astrophysical Phenomena Plasma Physics Space Physics We report striking Doppler velocity gradients observed during the well-observed September 10th 2017 solar flare, and argue that they are consistent with the presence of an above-the-looptop termination shock beneath the flare current sheet. Observations from the Hinode Extreme-ultraviolet Imaging Spectrometer (EIS) measure plasma sheet Doppler shifts up to 35 km/s during the late-phase of the event. By comparing these line-of-sight flows with plane-of-sky measurements, we calculate total velocity downflows of 200+ km/s, orientated 6-10° out of the plane of sky. The observed velocities drop rapidly at the base of the hot plasma sheet seen in extreme ultraviolet, consistent with simulated velocity profiles predicted by our 2.5D magnetohydrodynamics model that features a termination shock at the same location. Finally, the striking velocity deceleration aligns spatially with the suppression of Fe XXIV non-thermal velocities, and a 35--50 keV hard X-ray looptop source observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Together, these observations are consistent with the presence of a possible termination shock within the X8.2-class solar flare. |
| title | Doppler Signature of a Possible Termination Shock in an Off-Limb Solar Flare |
| topic | Solar and Stellar Astrophysics High Energy Astrophysical Phenomena Plasma Physics Space Physics |
| url | https://arxiv.org/abs/2402.04445 |