Articles by admin_cesra_editor

Energetics of compressive waves in the solar corona by Francesco Azzollini et al

2024-07-02

Inelastic scattering off moving or oscillating density fluctuations leads to broadening of radio signals propagating in the solar corona and solar wind. Using an anisotropic density fluctuation model from the kinetic scattering theory for solar radio bursts, we deduce the plasma velocities (perpendicular to the line of sight) required to explain observations of spacecraft signal frequency broadening. The kinetic energy associated with these inferred bulk velocities cascades to smaller and […]

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An Interactive Visual Tool for the Anisotropic Scattering of Solar Radio Bursts by Daniel L. Clarkson et al

2024-02-06

The turbulent heliosphere has a significant effect on the observed characteristics of radio emission produced in, or viewed through, the solar atmosphere. In particular, radio-wave scattering on density irregularities can broaden the observed decay times and source sizes, and shift the apparent source position. Both radio burst observations and simulations have demonstrated that the turbulence is anisotropic, which can explain both the observed decay times and source sizes simultaneously. Considering […]

Data-constrained Solar Modeling with GX Simulator by G. Nita et al

2023-08-08

In the dynamic realm of modern solar physics, where vast and diverse data sets challenge understanding, a critical need emerges for advanced data-constrained 3D modeling that combines photospheric magnetic fields measurements and a wide range of contextual electromagnetic radiation observations, which includes radio, X-ray, and extreme ultraviolet (EUV) emissions. Bridging all these available observational data constraints is imperative to create a comprehensive understanding of solar activity and phenomena. Addressing this […]

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

2023-07-04

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, […]

Electron acceleration efficiency during the impulsive phase of a solar flare: X-ray and microwave observations by Kontar et al

2023-06-20

Solar flares are known to be prolific electron accelerators, yet identifying the mechanism(s) for such efficient electron acceleration in magnetic reconnection events at the Sun (and similar astrophysical settings) presents a major challenge in Astrophysics (e.g. Holman et al 2011). Accelerated electrons with energies above $\sim 20$ keV are revealed by hard X-ray (HXR) bremsstrahlung emission, while accelerated electrons with even higher energies usually manifest themselves through radio gyrosynchrotron emission. […]

Radio measurements of coronal magnetic fields in fan-spine configurations on the Sun by B. Ryabov and A. Vrublevskis

2023-06-06

We are striving for more accurate coronal magnetography based on changes in radio polarization as microwaves cross magnetic field lines at nearly right angles. The theory of using quasi-transverse propagation for coronal field measurements includes weak dependence on two parameters: plasma density $N_e$ and the magnetic field divergence $L_d$ (see Alissandrakis and Gary, 2021 for a review). We evaluate coronal plasma density from local differential emission measure computed from the […]

Automated Detection and Statistical Study of Solar Radio Spikes by P.R. Lv et al

2023-04-26

Solar radio spikes’ most typical observational features are their short duration and narrow bandwidth. They appear on the solar radio dynamic spectrogram as a large number of narrow-band type-III bursts, spikes, dots, sub-second clumps, groups, chains, and other narrow-band structures from decimeter to decameter wavelengths (Feng et al.(2018), Tan et al.(2019)). We have improved the YOLOv5s network model for these characteristics by adding inclined bounding frames and attention and feature […]

Solar Radio Spikes and Type IIIb Striae Manifestations Triggered by a Coronal Mass Ejection by Clarkson et al

2023-04-11

Radio bursts are frequently emitted in the outer solar corona due to the acceleration of energetic electrons in solar flares and coronal mass ejections (CME). The shortest observed bursts are radio spikes, which have narrow spectral widths and are emitted over decades in frequency. Despite being studied for many years, imaging observations are sparse and restricted to localisation of the emission at decimetre frequencies (e.g. Benz, 2002). Recently, LOw Frequency […]

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