Quasi-periodic pulsations (QPP)

X-ray/Radio Quasi-periodic Pulsations Associated with Plasmoids in Solar Flare Current Sheets by Kumar, Karpen, and Dahlin

April 15, 2025

Plasmoids (or magnetic islands) are believed to play an important role in the onset of fast magnetic reconnection and particle acceleration during solar flares and eruptions. Direct imaging of flare current sheets and formation/ejection of multiple plasmoids in extreme ultraviolet (EUV) images, along with simultaneous X-ray and radio observations, provides significant insights into the mechanisms driving particle acceleration in solar flares. Previous studies have proposed that decimetric radio bursts and […]

The physics of solar spectral imaging observations in dm-cm wavelengths and space weather by Tan et al.

January 17, 2024

Recent years, several new generation solar radio telescopes operating in the centimeter decimeter (dm-cm) wavelengths have emerged in the world, including the Mingantu Spectral Radioheliograph (MUSER, 0.4-15GHz) (Yan et al. 2021), the Expanded Owens Valley Solar Array (EOVSA, 1-18GHz) (Gary et al. 2018), and the Siberian Radio Heliograph (SRH, 3-24GHz) (Altyntsev et al. 2020). Due to the fact that the solar radio emission in dm-cm wavelengths mainly originates from the […]

Imaging preflare broadband pulsations in the decimetric-metric wavelengths by Lv et al

July 4, 2023

Solar radio pulsations represent (quasi-)periodic or irregular short fluctuations observed from the radio flux curves or the dynamic spectra, in almost all wavelength ranges from metric to microwave (See the review by Nindos & Aurass 2007). They can be classified as broadband pulsations (BBPs) and narrowband pulsations (NBPs). Most earlier studies have focused on pulsations taking place during the impulsive or decay phases of solar flares. During the preflare stage, […]

Microwave imaging of quasi-periodic pulsations at flare current sheet by Yuankun Kou et al.

January 3, 2023

Quasi-periodic pulsations (QPPs; also known as quasi-periodic oscillations, i.e., QPOs) are phenomena that electromagnetic emissions vary quasi-periodically with time. They appear in celestial transient events with different temporal/spatial scales, such as stellar flares, gamma ray bursts and fast radio bursts, and etc. The Sun is a normal but the closest star from us, where flares with QPPs appear frequently (e.g. Zimovets et al. 2021 as a review). In the standard […]