Magnetic field value in the weak energy release region of the solar corona

Spectrographic data from observations of the polarized weak steplike (with relatively sharp growth t 3 sec and slow decay t 10² sec) solar continuum radioemission are analyzed below. The main results are found using a sweeping spectrograph in the 8–12 GHz frequency range (sweep rate 1 sample per second and frequency resolution 120 MHz) and using the RT-22 radio telescope at the Crimean Astrophysical Observatory (angular resolution 4–6). In a series of events at the leading edge of the continuum a narrow-band frequency drifting emission termed blip-type is found. The degree of continuum circular polarization (p<10%) is low compared to that of the narrow-band component (p20%). Both components of the aforementioned events should be radiating on the second harmonic of the local plasma frequency in the context of a plasma generating mechanism. Based on the model proposed and using the observed degree of circular polarization of each component, we can estimate the strength of the magnetic field within the area of the source and the width of the angular spectrum from the radiating plasma turbulence. The results of analysis of the real microwave events are given below.Radiophysical Research Institute, Nizhnii Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 7, pp. 874–882, July, 1994.     

Bayesian calibration

Two methods of analyzing calibration data are compared: the familiar least-squares method and an empirical Bayes method. The least-squares method uses the information obtained from the current calibration run but ignores all information obtained from previous runs. The empirical Bayes method uses the current information plus summarized information from past calibration runs, e.g., estimates of the means and variances of the parameters. Both methods are applied to simulated and real data. The empirical Bayes method is defined for any number of calibration standards, while the definition of the least-squares method requires modification when the number of standards is less than the number of parameters. The absolute error in predicting unknown analyte concentrations is used as a measure of goodness of calibration. When only one or two standards are used, the Bayes method results in better calibration than the least-squares method; e.g., with one standard, the average error with the Bayes method is at least 30% less than that with the least-squares method. The Bayes method is most useful when (i) run-to-run variation in calibration parameters is small (yet large enough to warrant regular calibration), (ii) residual error is significant, and (iii) it is desirable to use few calibration standards.     

The Results of Studying Nonstationary Processes on the Sun by Radioastronomical Methods

This paper presents the results of studies of solar phenomena performed at the Radiophysical Research Institute (NIRFI) in the last years and based on the data of measuring the solar microwave radiation. We obtained new results concerning fragmentation of the regions of initial energy release during solar flares, their spatial and temporal dynamics, the physical conditions in flaring loops, the dynamics of energetic particles accelerated during flares, and the characteristics of sporadic radio emission during the formation and propagation of coronal mass ejections in the lower layers of the solar atmosphere.     

A study of preflare situations using spectral data on fluxes of solar radio emission in the period from 1970 to 1994

We present the results of observations performed at “Zimenki” facility at six radio frequencies over a broad spectral interval in the period that covers more than two 11-year cycles of the solar activity. In the analysis we have determined the laws of the spectral-time development of the preflare situations for the proton and non-proton events, which differ by the duration and range of spectral composition of the phenomena. The phenomenon of the “directivity” of precursor radiation is studied depending on the location of sources on the solar disc.     

Solar microwave precursors and coronal mass ejection: Possible connection

Radiophysical Research Institute (NIRFI), Nizhny Novgorod (Gorky), Russia. Published in Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 7, pp. 883–886, July, 1994.