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High-frequency oscillations in small chromospheric bright features observed with Atacama Large
J C Guevara Gómez1,2, S Jafarzadeh1,2, S Wedemeyer1,2
1Rosseland Centre for Solar Physics, University of Oslo, PO Box 1029 Blindern, 0315 Oslo, Norway.
Summary
High-cadence observations detected oscillations in small solar chromosphere features. These findings suggest the presence of fast sausage-mode and possibly Alfvénic waves, crucial for energy transport in the Sun's outer atmosphere.
Area of Science:
- Solar Physics
- Plasma Astrophysics
- Wave Phenomena
Background:
- The solar chromosphere is a dynamic region where energy is transported and dissipated.
- Understanding wave phenomena in the chromosphere is key to comprehending energy transfer to the outer solar atmosphere.
Purpose of the Study:
- To detect and characterize oscillations in small-scale features within the solar chromosphere.
- To investigate the nature of these oscillations and their implications for wave propagation.
Main Methods:
- Utilized high temporal resolution observations (2s cadence) from the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 3 (100 GHz).
- Analyzed brightness temperature, size, and horizontal velocity of three small bright features in a plage/enhanced-network region.
- Identified oscillatory behavior and periods ranging from approximately 66s to 110s.
Main Results:
- Detected oscillations in brightness temperature, size, and horizontal velocity of three small chromospheric features.
- Observed anti-correlations between perturbations, suggesting fast sausage-mode waves.
- Evidence for transverse oscillations indicates potential Alfvénic (kink) waves.
Conclusions:
- High-cadence ALMA observations are effective for diagnosing high-frequency magnetohydrodynamic waves in the solar chromosphere.
- These detected waves may play a significant role in channeling energy into the Sun's outer atmosphere.
- The study highlights the potential of ALMA for advancing our understanding of solar atmospheric dynamics.
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