Decimetric emission 500 arcseconds away from a flaring site: Possible scenarios from GMRT solar radio observations by Bisoi et al.*4 Sep 2018, 09:25 UTC
The displaced positions of radio sources away from the true source locations are usually observed in radio images at metric and decimetric wavelengths (Duncan 1979, Benz et al. 2002, Kundu et al., 2006, Kontar et al., 2017, Mann et al., 2018). The displaced radio source location is the apparent source position, that result from the scattering of radio waves (Kontar et al. 2017) or by coronal propagation effects (Mann et al., 2018). The other possibility is the wave ducting effect (Duncan 1979), wherein the ducting of radio emission, produced lower in the corona, along a density-depleted magnetic flux tube can lead to a shift in the position of the true radio source. Here we present an unusual decimetric emission located 500 arcsec away from a flaring site, as observed from the first high time cadence Giant Meterwave Radio Telescope (GMRT) solar images at 610 MHz, that we believe to be possibly due to the wave-ducting effect.
Figure 1. From left to right, the GMRT images at 610 MHz (top row) and their contour images overlaid on background SDO/HMI (middle row) and SDO/AIA 94 A (bottom row) images, respectively, at the peak times of the C1.4 and M1.0 flares and ...