Solar Radio Burst Associated with a Falling Bright EUV Blob
by M. Karlický et al.*

2018-06-12 474 views

In several papers the thermal conduction front formed between hot and cold plasmas was studied (Brown et al. 1979, McKean et al 1990, Arber & Melnikov 2009). Karlický (2015) has studied the thermal front using a 3-D particle-in-cell electromagnetic code and found that the thermal front can produce radio emission. Here we present a very rare radio burst which we interpreted as generated by the thermal conduction front formed in […]

Properties of Decameter IIIb–III Pairs
by V. Melnik et al.*

2018-05-29 228 views

A large number of Type IIIb–III pairs, in which the first component is a Type IIIb burst and the second one is a Type III burst, are often observed during decameter Type III burst storms. From the beginning of their detection, the question of whether the components of these pairs are the first and the second harmonics of radio emission or not has remained open. We discuss properties of decameter […]

Modeling of Solar Atmosphere Parameters Above Sunspots Using RATAN-600 Microwave Observations
by A.G. Stupishin et al.*

2018-05-15 402 views

Models of the upper transition region of sunspots have been derived based on the observed radio spectrum between 3 and 18 GHz from Radio Astronomical Telescope of the Academy of Sciences 600 (RATAN-600) observations. Our objective is to match the spectrum to show that, within the limits of the one-dimensional observations and modeling, we have obtained a reasonable description of the upper transition-region structure of sunspots. We have developed a diagnostic […]

LOFAR observations of Fine Fundamental and Harmonic Structures in Solar Radio Bursts
by Xingyao Chen et al*

2018-05-01 512 views

Type III solar radio bursts are believed to be the most sensitive signatures of near-relativistic electron beam propagation in the corona. These intense bursts of solar radio emissions sometimes appear in the dynamic spectrum as a chain of several elementary bursts, which are known as striae, so an individual burst is composed of myriad of such stria (de La Noe & Boischot, 1972). Although there are several generation mechanisms of […]

Solar Type-IIIb Radio Bursts as Tracers for Electron Density Fluctuations in the Corona
by V. Mugundhan et al.*

2018-04-17 226 views

Type III bursts are generated when an electron accelerated close to speed of light excite the layers of coronal plasma they encounter when travelling away from the sun. These bursts are seen in a time-frequency-intensity image (called dynamic spectrum, as the time variation of the spectrum is visualized by it) as a bright patch, drifting from high to low frequencies on short time-scales ($\approx$ few-seconds). At times, along the path […]

New evidence for a coronal mass ejection driven fast drifting type II radio burst
by K. Anshu et al.

2018-04-03 556 views

Type II solar radio bursts are considered to originate from plasma waves excited by magnetohydrodynamic (MHD) shocks and converted into radio waves at the local plasma frequency and its harmonics. Type II radio bursts are mostly associated with coronal mass ejections (CMEs) and flares Nindos et al. (2008). We studied a seldom occurring high frequency type II burst on 4th Novemeber 2015, which had both fundamental and harmonic components. The […]

Association of radio polar cap brightening with bright patches and coronal holes
by C. L. Selhorst et al.*

2018-03-20 296 views

The purpose of this work is to model the emission of 17 GHz polar bright patches, which are frequently observed by the Nobeyama Radioheliograph (NoRH) in association with coronal holes. Although these bright regions have been observed for a few decades, their nature remains unclear. Our simulations were based on the temperature and density profiles from the SSC atmospheric model (Selhorst et al., 2005), with modifications to include a coronal […]

Dressing the Coronal Magnetic Extrapolations of Active Regions with a Parameterized Thermal Structure
by Gelu M. Nita et al.

2018-03-06 359 views

The study of time-dependent solar active region morphology and its relation to eruptive events requires analysis of imaging data obtained in multiple wavelength domains with differing spatial and time resolutions, ideally in combination with 3D physical models. To facilitate this goal, we have undertaken a major enhancement of our IDL-based simulation tool, GX Simulator, originally developed for modeling microwave and X-ray emission from flaring loops (Nita et al. 2015), to […]

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