Community of European Solar Radio Astronomers – Page 5

Two-element interferometer for millimeter-wave solar flare observations, by Yu et al.

2023-08-29

Solar radio emission can be significantly influenced by Earth’s atmosphere when transmitting towards the Earth’s surface, due to atmospheric turbulence and the absorption of vapor and oxygen molecules etc. Consequently, antennas receive signals with a ‘dither’ component, indicating a noise signal exhibiting random variations. As a result, the sensitivity of observing systems distorts severely , especially for weaker radio bursts in the millimeter passband. Weak bursts can be usually observed […]

Solar electron beam velocities that grow Langmuir waves in the inner heliosphere by C. Y. Lorfing et al.

2023-08-15

Solar accelerated electron beams interact with the background plasma of the solar wind to locally generate Langmuir waves and subsequently produce radio emission (Ginzburg and Zhelezniakov 1958). Numerous observations at different distances from the Sun by spacecrafts like Solar Orbiter (0.5AU) and ACE (1AU) show different energy ranges of electrons interacting with the plasma to produce Langmuir oscillations. At 0.5AU, non-thermal electrons in the deca-keV range arrive co-temporal to the […]

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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