Systematic capture of MeV electron beams by MWR

Every ~ 53 days since August 2016, Juno swings by Jupiter and as the spacecraft spins along a polar orbit, measurements of Jupiter's microwave radiation are carried out at high data rates for several hours (~ 9 hours) with the Juno Microwave Radiometer (MWR). Within ~ 6 planetary radii (Rj) and from inside/outside the magnetospheric region, the thermal and synchrotron emissions are measured at high temporal and spatial resolutions. In this paper, we present a synthesis of the spatial distributions of the microwave radiation and discuss the similarities and differences observed at six wavelengths (1.3-50 cm). In addition to the thermal emission and synchrotron radiation from Jupiter's electron belt, unexpected signatures in MWR are either systematically or sporadically reported during perijove 1 (PJ1) and PJ3-PJ6. The preliminary results of a multi-instrument analysis of radio (MWR), extreme and far-ultraviolet auroral emissions (Juno UVS), field (Juno magnetometer), keV electrons (JEDI), and background radiation signatures in Juno's ASC and SRU instruments suggest that some of these signatures are consistent with the capture by MWR of synchrotron emission radiated by MeV electron beams, which may be associated with auroral activity. We subsequently describe in detail our data analysis and effort to model the synchrotron radiation from MeV electron beams to support our findings.