Oscillatory response of the solar chromosphere to a strong downflow event above a sunspot
- Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)
- Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)
- Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom)
We report three-minute oscillations in the solar chromosphere driven by a strong downflow event in a sunspot. We used the Fast Imaging Solar Spectrograph of the 1.6 m New Solar Telescope and the Interface Region Imaging Spectrograph (IRIS). The strong downflow event is identified in the chromospheric and transition region lines above the sunspot umbra. After the event, oscillations occur at the same region. The amplitude of the Doppler velocity oscillations is 2 km s{sup −1} and gradually decreases with time. In addition, the period of the oscillations gradually increases from 2.7 to 3.3 minutes. In the IRIS 1330 Å slit-jaw images, we identify a transient brightening near the footpoint of the downflow detected in the H α +0.5 Å image. The characteristics of the downflowing material are consistent with those of sunspot plumes. Based on our findings, we suggest that the gravitationally stratified atmosphere came to oscillate with a three-minute period in response to the impulsive downflow event as was theoretically investigated by Chae and Goode.
- OSTI ID:
- 22654345
- Journal Information:
- Astrophysical Journal Letters, Vol. 821, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
DYNAMICS IN SUNSPOT UMBRA AS SEEN IN NEW SOLAR TELESCOPE AND INTERFACE REGION IMAGING SPECTROGRAPH DATA
ALMA Discovery of Solar Umbral Brightness Enhancement at λ = 3 mm