Fast Prograde Coronal Flows in Solar Active Regions

Abstract

We report the discovery and characterization of high-speed (>100 km/s) 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 behavior does not depend upon active-region latitude or solar cycle, with similar behavior in Cycles 24 and 25.

References in corpus (7)

• Solar UV and X-Ray Spectral Diagnostics
• Full-Sun observations for identifying the source of the slow solar wind
• Temperature and Emission-Measure Profiles Along Long-Lived Solar Coronal Loops Observed with TRACE
• Asymmetries of solar coronal extreme ultraviolet emission lines
• Multiple Component Outflows in an Active Region Observed with the EUV Imaging Spectrometer on Hinode
• The coronal source of extreme-ultraviolet line profile asymmetries in solar active region outflows
• Doppler speeds of the hydrogen Lyman lines in solar flares from EVE