Determination of plasma parameters in solar zebra radio sources

0449312 - ASÚ 2016 RIV FR eng J - Journal Article
Karlický, Marian - Yasnov, L. V.
Determination of plasma parameters in solar zebra radio sources.
Astronomy & Astrophysics. Roč. 581, September (2015), A115/1-A115/6. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR GAP209/12/0103
Grant - others:EC(XE) 606862
Program: FP7
Institutional support: RVO:67985815
Keywords : Sun * flares * radio radiation
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 5.185, year: 2015

We present a new method for determining the magnetic field strength and plasma density in the solar zebra radio sources. Using the double plasma resonance (DPR) model of the zebra emission, we analytically derived the equations for computing the gyroharmonic number s of selected zebra lines and then solved these equations numerically. The method was successfully tested on artificially generated zebras and then applied to observed ones. The magnetic field strength and plasma density in the radio sources were determined. Simultaneously, we evaluated the parameter L-nb = 2(Lb/)(2(Ln)-L-b), where L-n and L-b are the characteristic scale-heights of the plasma density and magnetic field strength in the zebra source, respectively. In models with smaller density gradients, such as those with a barometric density profile, the microwave zebras cannot be produced owing to the strong bremsstrahlung and cyclotron absorptions. We also show that our DPR model is able to explain the zebras with frequency-equidistant zebra lines.
Permanent Link: http://hdl.handle.net/11104/0250903