1. Radio Emission from Masuda Sources New Jersey Institute of Technology Sung-Hong Park

2. Contents Introduction of Masuda Sources Introduction of Masuda Sources Gyro-Synchrotron Radiation (GSR) from Masuda Sources Gyro-Synchrotron Radiation (GSR) from Masuda Sources Diffusive Synchrotron Radiation (DSR) from Masuda Sources Diffusive Synchrotron Radiation (DSR) from Masuda Sources Discussion & Summary Discussion & Summary

3. 1-1. Yohkoh SXT and HXT Specification Instrument Fourier-synthesis type collimator Energy band 15-24-35-57-100 keV (4 bands) Angular resolution ~ 5 arc sec Field of view Full solar disk Effective area ~ 70 cm 2 Time resolution 0.5 sec Instrument Modified Wolter type I grazing incident mirror Wavelength range 3-60 Å (selectable with filters) Angular resolution ~ 2.5 arc sec Field of view Full solar disk Time resolution Up to 0.5 sec

4. 1-2. X-ray Observation of Masuda Flares Image of the Soft X-ray Telescope (SXT) and the Hard X-ray Telescope (HXT) on board the Yohkoh satellite

5. 1-3. Plasma Parameters of Masuda Sources Emitting Volume, V [cm 3 ] 1.25 ·10 26 Electron Number Density, n e [cm -3 ] 10 9 Electron Temperature, T e [K] 2 ·10 7 Spectral Index of Electron Energy Distribution, δ 3 Magnetic field Strength, B [G] 40-120

6. 2-1. Gyro-Synchrotron Radiation (GSR)

7. 2-2. Klein’s Approximate numerical treatment of GSR The emissivity j and absorption coefficient k radiated by n* particles per unit volume with charge –q and mass m in a magnetic field B are then

8. 2-2. Klein’s Computation Code for GSR If the pitch-angle integration by Laplace’s method of approximate asymptotic integration and a weakly anisotropic distribution (Petrosian 1981) are considered,

9. 2-3. GSR from Masuda Sources

11. 3-1. Diffusive Synchrotron Radiation

12. 3-2. Derivation for Non-Relativistic DSR

15. 3-3. Estimation of Randomly Magnetic Field Strength

16. 3-4. Calculation of the NRDSR intensity from electrons

17. 3-5. NRDSR from Masuda Sources

18. 3-5. NRDSR from Masuda sources

19. 4. Discussion & Summary The GSR and DSR are very different for different model of the Masuda sources, which implies a way of distinguishing between the models. The GSR and DSR are very different for different model of the Masuda sources, which implies a way of distinguishing between the models. To observe the radio emissions from the Masuda sources, we need a radio telescope (or array) which has 1-10 GHz observational frequency band with high spectral resolution and at least 7 arcsec spatial resolution corresponding to the typical size of the Masuda sources. To observe the radio emissions from the Masuda sources, we need a radio telescope (or array) which has 1-10 GHz observational frequency band with high spectral resolution and at least 7 arcsec spatial resolution corresponding to the typical size of the Masuda sources.