CESRA science nuggets

Particle Acceleration and heating by turbulent reconnection by L. Vlahos, T. Pisokas, H. Isliker, V. Tsiolis and A. Anastasiadis

August 9, 2016

Fermi (1949) introduced a fundamental stochastic process to solve the problem of particle energization (heating and/or acceleration) in space and astrophysical plasmas. The initial idea of Fermi with randomly moving scatterers (magnetic clouds), was soon replaced with a spectrum of low amplitude (δΒ/Β<<1) waves and termed particle acceleration by MHD (weak) turbulence. In the other extreme, isolated turbulent shock waves or isolated unstable current sheets (UCS) were studied. The regime […]

Observation of a Quasi-periodic Pulsation in Hard X-Ray, Radio, and Extreme-ultraviolet Wavelengths by Pankaj Kumar, Valery M. Nakariakov and Kyung-Suk Cho

August 2, 2016

Quasi-periodic pulsations (QPPs) with periods from a few seconds to several minutes are often observed during solar/stellar flares in X-ray, radio, and optical wavelength bands. The study of QPPs is useful to understand the physical mechanism for the energy release, plasma heating, and particle acceleration during solar flares…

Radio emission and relativistic proton acceleration in the large solar particle event of 20 Jan 2005 by Karl-Ludwig Klein and Sophie Masson

January 16, 2015

Energetic particle acceleration Enhanced fluxes of solar energetic particles (SEP) – so-called SEP events – result from processes of explosive energy conversion in the corona, notably flares and coronal mass ejections. The highest energies of solar energetic nucleons detected in space or through gamma-ray emission in the solar atmosphere are in the GeV range. Where and how the particles are accelerated is still controversial. The most debated candidate processes are […]

Signatures of Magnetoacoustic Wave Trains in Solar Decimetric Radio Type IV Bursts by Hana Mészárosová, Marian Karlický, Ján Rybák, and Karel Jiricka

November 9, 2009

It has been theoretically predicted (Roberts et al. 1983, 1984) that the periodicity of magnetoacoustic modes can be modified by the time evolution of an impulsively generated signal. One of the obvious sources of such a disturbance is the impulsive flare process. These magnetoacoustic waves are trapped in regions with higher density (e.g., in coronal loops) acting as waveguides. The impulsively generated wave in such a coronal waveguide exhibits three […]

Sixty-five years of solar radioastronomy – review paper published by Monique Pick and Nicole Vilmer

March 18, 2009

A review paper presenting the input of 65 years of radio observations has been published in the journal Astronomy and Astrophysics Review, October 2008 issue. The authors, Monique Pick and Nicole Vilmer, present first the historical context starting from the early 1940s and then proceed to show how radio astronomy has contributed to our knowledge in solar and solar-terrestrial physics. The review is focused on radio emission from flares and […]