Related papers: Incoherent Solar Radio Emission
Microwave emission of solar flares is formed primarily by incoherent gyrosynchrotron radiation generated by accelerated electrons in coronal magnetic loops. The resulting emission depends on many factors, including pitch-angle distribution…
The quiet Sun, i.e. in its non-flaring state or non-flaring regions, emits thermal radiation from radio to ultraviolet. The quiet Sun produces also non-thermal radiation observed in gamma rays due to interactions of Galactic Cosmic Rays…
Observations in the sub-THz range of large solar flares have revealed a mysterious spectral component increasing with frequency and hence distinct from the microwave component commonly accepted to be produced by gyrosynchrotron (GS)…
With the invention of new far-infrared (FIR) and radio mm and sub-mm instruments (DESIR on SMESE satellite, ESO-ALMA), there is a growing interest in observations and analysis of solar flares in this so far unexplored wavelength region. Two…
The first evidence of the gamma-ray emission from the quiescent Sun was found in the archival EGRET data that was later confirmed by Fermi-LAT observations with high significance. This emission is produced by Galactic cosmic rays (CRs)…
The radio emission of the quiet Sun in the metric and decametric bands has not been well studied historically due to limitations of existing instruments. It is nominally dominated by thermal brehmsstrahlung of the solar corona, but may also…
Recent solar flare observations in the sub-THz range have provided evidence of a new spectral component with fluxes increasing for larger frequencies, separated from the well-known microwave emission that maximizes in the GHz range.…
The Letter takes up a question of what radio emission is produced by electrons at the very acceleration site of a solar flare. Specifically, we calculate incoherent radio emission produced within two competing acceleration…
At radio wavelengths, solar-type stars emit thermal free-free and gyroresonance, gyrosynchrotron, and impulsive coherent emission. Thermal free-free emission originates at layers where the optical depth is close to unit, while high…
The spectrum of gyrosynchrotron emission from solar flares generally peaks in the microwave range. Its optically-thin, high-frequency component, above the spectral peak, is often used for diagnostics of the nonthermal electrons and the…
Cosmic ray air showers have been known for over 30 years to emit pulsed radio emission in the frequency range from a few to a few hundred MHz, an effect that offers great opportunities for the study of extensive air showers with upcoming…
Recently, in a few case studies we demonstrated that gyrosynchrotron microwave emission can be detected directly from the acceleration region when the trapped electron component is insignificant. For the statistical study reported here, we…
During solar flares fast electron beams generated in the solar corona are non-thermal radio sources in terms of type III bursts. Sometimes they can enter into the interplanetary space, where they can be observed by in-situ measurements as…
During Type III solar radio bursts, electromagnetic waves are radiated at plasma frequency $\omega_p$ and its harmonics by electrostatic wave turbulence generated by electron beams ejected by Sun in randomly inhomogeneous solar wind and…
The dynamics of the partially ionized solar atmosphere is controlled by the frequent collision and charge exchange between the predominant neutral Hydrogen atoms and charged ions. At signal frequencies below or of the order of either of the…
Extensive air showers (EAS) have been known for over 30 years to emit pulses of radio emission at frequencies from a few to a few hundred MHz, an effect that offers great opportunities for the study of EAS with the next generation of…
Solar flares and coronal mass ejections (CMEs) can accelerate electrons, causing bursts such as type IV emissions in the solar radio continuum. Although radio spectroscopy is a powerful diagnostic tool for the corona, the origin and…
Numerous magnetic hot stars exhibit gyrosynchrotron radio emission. The source electrons were previously thought to be accelerated to relativistic velocities in the current sheet formed in the middle magnetosphere by the wind opening…
This paper investigates the incidence of coherent emission in solar radio bursts, using a revised catalog of 3800 solar radio bursts observed by the Nobeyama Radio Polarimeters from 1988 to 2023. We focus on the 1.0 and 2.0 GHz data, where…
Coherent radio emission mechanism of solar radio bursts is one of the most complicated and controversial topics in solar physics. To clarify the mechanism(s) of different types of solar radio bursts, (radio) wave excitation by energetic…