CALLISTO Facilities in Peru: Spectrometers Commissioning and Observations of Type III Solar Radio Bursts

TL;DR

This paper reports on the commissioning of CALLISTO spectrometers in Peru, their performance in observing Type III solar radio bursts, and their potential to study solar dynamics from an equatorial location.

Contribution

It introduces two new radio spectrometer stations in Peru, evaluates their site suitability, and demonstrates their capability to observe and analyze Type III solar radio bursts.

Findings

Characterized Type III bursts with mean drift rate of -25.8 MHz/s

Measured burst durations of approximately 2.6 seconds

Observed bandwidths around 35 MHz in the 114-174 MHz range

Abstract

The Astrophysics Directorate of CONIDA has installed two radio spectrometer stations belonging to the e-CALLISTO network in Lima, Peru. Given their strategic location near the Equator, it is possible to observe the Sun evenly throughout the whole year. The receiver located at Pucusana, nearby the capital city of Lima, took data from October 2014 until August 2016 in the metric and decimetric bands looking for radio bursts. During this period, this e-CALLISTO detector was unique in its time-zone coverage. To assess the suitability of the sites and the performance of the antennas we analyzed the radio ambient background and measured their radiation pattern and beam-width. To show the capabilities of the facilities to study solar dynamics in these radio frequencies we have selected and analyzed type III Solar Radio Bursts. The study of this kind of bursts helps to understand the electron beams traversing the solar corona and the solar atmospheric density. We have characterized the most common radio bursts with the following mean values: a negative drift rate of -25.8 $\pm$ 3.7 MHz/s, a duration of 2.6 $\pm$ 0.3 s and 35 MHz bandwidth in the frequency range of 114 to 174 MHz. In addition, for some events, it was possible to calculate a global frequency drift which on average was 0.4 $\pm$ 0.1 MHz/s.