Fast prograde coronal flows in solar active regions
Abstract
We report the discovery and characterization of high-speed (>100 km s-1) horizontal flows in solar active regions, making use of the Sun-as-a-star spectroscopy in the range 5-105 nm provided by the EVE (Extreme Ultraviolet Variability Experiment) spectrometers on the Solar Dynamics Observatory. These apparent flows are persistent on time-scales of days, and are well observed in lines of Mg X, Si XII, and Fe XVI for example. They are prograde, as evidenced directly by blueshifts/redshifts peaking at the east/west limb passages of isolated active regions. The high-speed flow behaviour does not depend upon active-region latitude or solar cycle, with similar behaviour in Cycles 24 and 25.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2022
- DOI:
- 10.1093/mnrasl/slac079
- arXiv:
- arXiv:2207.13461
- Bibcode:
- 2022MNRAS.515L..84H
- Keywords:
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- Sun: corona;
- Sun: X-rays;
- gamma-rays;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- doi:10.1093/mnrasl/slac079