First Solar Radio Burst Observations by the Mexican Array Radio Telescope (MEXART) at 140 MHz

Abstract

The National Laboratory of Space Weather in Mexico (Laboratorio Nacional de Clima Espacial: LANCE) coordinates instrumentation for monitoring the space-weather impact over Mexico. Two of these instruments are the Mexican Array Radio Telescope (MEXART) and Compound Astronomical Low frequency Low cost Instrument for Spectroscopy and Transportable Observatory (CALLISTO) station from the e-CALLISTO network (CALLMEX). Both instruments are located at the same facility (Coeneo Michoacan, Mexico) and share a spectral band centered at 140 MHz. In this work we show the capabilities of the e-CALLISTO network as support to identify a solar radio burst in the signal of the MEXART radiotelescope. We identify 75 solar radio bursts in the MEXART signal: five events of Type II and 70 of Type III between September 2015 and May 2019. The analysis of solar radio bursts in the MEXART signal provide us valuable information about the development of the radio event due their high sensitivity, time resolution, and isotropic response. For the case of Type III solar radio events, we identify three characteristic phases in the dynamical evolution of the signal at 140 MHz: a pre-phase, a main peak, a decay phase, and a post-event phase. A Morlet wave transform was done of MEXART signals in the Type III solar radio busts; in their spectra it was identified a pine tree structure preceding the main event in the time series. These characteristics are not observable in the data from the e-Callisto network.