Related papers: The slow magnetoacoustic mode in the flaring loop
X-ray observations of solar flares routinely reveal an impulsive high-energy and a gradual low-energy emission component, whose relationship is one of the key issues of solar flare study. The gradual and impulsive emission components are…
Using the cross-spectral method, we confirm the existence of the X-ray hard lags discovered with cross-correlation function technique during a large flare of Mrk 421 observed with BeppoSAX . For the 0.1--2 versus 2--10keV light curves, both…
Using the ULTRASPEC instrument mounted on the 2.4-m Thai National Telescope, we observed two large flares, each with a total energy close to 10^34 erg with sub-second cadence. A combination of a wavelet analysis, a Fourier transform plus an…
Propagating slow magneto-acoustic waves are often observed in polar plumes and active region fan loops. The observed periodicities of these waves range from a few minutes to few tens of minutes and their amplitudes were found to decay…
Fast radio bursts (FRBs) are millisecond-duration extragalactic radio transients of unknown origin. Rotation measures (RMs) probe their local magneto-ionic environments and provide important clues to their nature. While RM variability has…
(Abridged) We report results from a comprehensive study of the nearby M dwarf Proxima Centauri with the XMM-Newton satellite. We find strongly variable coronal X-ray emission, with flares ranging over a factor of 100 in peak flux. The…
We study the properties of slow magneto-acoustic waves that are naturally excited due to turbulent convection and investigate their role in the energy balance of a plage region using three dimensional (3D) radiation-MHD simulations. We…
Spectroscopic observations covering the wavelength range 3600--4600\AA are presented for a large flare on the late type M dwarf AT Mic (dM4.5e). A procedure to estimate the physical parameters of the flaring plasma has been used which…
Context. Quasi-periodic pulsations (QPPs) typically display periodic and regular peaks in the light curves during the flare emissions. Sometimes, QPPs show multiple periods at the same wavelength. However, changing periods in various…
We report on the multi-frequency multi-epoch radio observations of the magnetar, XTE J1810-197, which exhibited a radio outburst from December 2018 after its 10-year quiescent period. We performed quasi-simultaneous observations with VERA…
Fast Radio Bursts (FRBs) are millisecond-duration radio pulses with largely unknown origins, with a subset exhibiting repeating behavior. Magnetars highly magnetized neutron stars and a leading progenitor candidate for FRBs also produce…
In this article, we measure the mean magnetic shear from the morphological evolution of flare ribbons, and examine the evolution of flare thermal and non-thermal X-ray emissions during the progress of flare reconnection. We analyze three…
Large-scale solar eruptions have been extensively explored over many years. However, the properties of small-scale events with associated shocks have been rarely investigated. We present the analyses of a small-scale short-duration event…
High frequency oscillations are observed in a neon plasma of a direct current magnetron discharge. At low discharge currents, we see highly coherent 60 MHz fluctuations. Above a distinct current threshold, secondary 5 - 10 MHz fluctuations…
FRB 180916 is a most intriguing source at 150 Mpc distance capable of producing repeating fast radio bursts with a periodic 16.35 day temporal pattern. We report on the X-ray and $\gamma$-ray observations of FRB 180916 obtained by AGILE and…
A recent study by Nakariakov et al. pointed out that the dispersion relation of MHD sausage mode oscillations has been incorrectly applied to coronal loops, neglecting the highly dispersive nature of the phase speed and the long-wavelength…
We study the nature of energy release and transfer for two sub-A class solar microflares observed during the second flight of the Focusing Optics X-ray Solar Imager (FOXSI-2) sounding rocket experiment on 2014 December 11. FOXSI is the…
We present SDO/AIA observations of an eruptive X-class flare of July 12, 2012, and compare its evolution with the predictions of a 3D numerical simulation. We focus on the dynamics of flare loops that are seen to undergo slipping…
Most studies of quasi-periodic pulsations in solar flares have identified characteristic periods in the 5 - 300s range. Due to observational limitations there have been few attempts to probe the < 5s period regime and understand the…
We analyse quasi-periodic pulsations (QPP) detected in the microwave and decimeter radio emission of the SOL2017-09-05T07:04 solar flare, using simultaneous observations by the Siberian Radioheliograph 48 (SRH-48, 4-8 GHz) and Mingantu…