2016/04/08 by Hannah Kwak, Jongchul Chae, Donguk Song +3 · 2 citations
Physics and Astronomy · #Amplitude #Atmosphere (unit) #Chromosphere #Event (particle physics) #Scientific Research and Discoveries #Solar and Space Plasma Dynamics #Solar telescope #Spectrograph #Stellar, planetary, and galactic studies #Sunspot #astro-ph.SR
paper · pdf · doi:10.3847/2041-8205/821/2/l30
13 pages, 4 figures, accepted for publication in ApJ Letters
arxiv created 2016/04/08 · openalex publication_date 2016/04/19 · arxiv updated 2016/04/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
ABSTRACT 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 −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 & Goode.