Modulation of radio emission, fast magnetoacoustic waves and magnetic field measurements in the solar corona with LOFAR
by Kolotkov et al*

2018-08-21 569 views

Fast magnetoacoustic wave trains are a promising seismological probe of the corona, revealing the magnetic connectivity and providing the estimation of the absolute value of the coronal magnetic field. Low-frequency radio observations allow for the detection of fast wave trains in middle and upper corona, above the field-of-view of EUV imagers and spectrographs, via the modulation of the radio emission by the variations of the electron concentration. We present the […]

Topical issue “Solar radio physics from the chromosphere to near Earth” published
by E.P Kontar and A. Nindos

2018-06-26 588 views

The 2016 CESRA workshop (http://cesra2016.sciencesconf.org) had a special emphasis on the complementarity of current and future space-based observations with ground-based radio observations. It was the place to discuss the new exciting science opportunities that arise from radio instruments such as the Atacama Large Millimeter/submillimeter Array (ALMA), the Expanded Owens Valley Solar Array (EOVSA), the Expanded Very Large Array (EVLA), the Low Frequency array (LOFAR), the Mingantu Spectral Radioheliograph (MUSER), and […]

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

2018-05-15 602 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 […]

Estimation of a CME magnetic field strength using observations of gyrosynchrotron radiation
by E. P. Carley et al.*

2018-01-09 763 views

Despite many years of study, the dominant driver and energy source of coronal mass ejections (CMEs) is still under investigation. Observational studies have indicated that magnetic energy represents the largest part of the total energy budget of the eruption (Emslie et al., 2012, Carley et al., 2012). However, despite having such a dominant influence on CME dynamics, little is known about CME magnetic field. This is due to the scarcity […]

VLA Measurements of Faraday Rotation through Coronal Mass Ejections
by Jason E. Kooi et al*

2017-11-21 458 views

Coronal mass ejections (CMEs) are large-scale eruptions of ionized gas (or plasma) from the Sun. The ejected material of a CME is associated with strong magnetic fields, which can cause substantial geomagnetic storms at Earth that enhance the radiation space environment and affect global communications and geolocation. Remote-sensing techniques such as Faraday rotation (FR), the rotation of the plane of polarization of linearly polarized radiation as it propagates through a […]

Acceleration and Storage of Energetic Electrons in Magnetic Loops in the Course of Electric Current Oscillations
by V.V. Zaitsev and A.V. Stepanov

2017-10-31 594 views

There are long-lived radio events on the Sun and stars like in type IV solar radio bursts with sudden reductions and pulsating type III bursts (Slottje, 1972; Huang et al. 2016) as well as intriguing intense radio emission from ultracool stars that lasts for several rotation periods (Hallinan et al. 2007). This can be the result of the multiple injections of accelerated electrons into the coronal magnetic loops. The idea […]

Solar plasma radio emission and inertial Alfvén turbulence
by O. Lyubchyk et al.*

2017-09-26 547 views

We study the influence of kinetic-scale Alfvénic turbulence on the generation of plasma radio emission in the solar coronal regions where the plasma/magnetic pressure ratio $\beta $ is smaller than the electron/ion mass ratio $m_{e}/m_{i}$. The present study is motivated by the phenomenon of solar type I radio storms associated with the strong magnetic field of active regions. The measured brightness temperature of the type I storms can be up […]

Combining radio and optical observations for coronal magnetic field determination
by Henry Aurass

2006-02-15 184 views

We present a method newly developed at the Astrophysikalisches Institut Potsdam (AIP) for determining the structure and the strength of coronal magnetic fields during the late phase of solar flares. Fiber bursts Fiber bursts are a spectral fine structure occuring in some type IV radio burst continua. Here we assume that the fiber bursts are excited by whistler waves and their interaction with nonthermal electrons trapped in a magnetic loop. […]