The brightness temperatures of the main Galactic radio-loops at 22 MHz

TL;DR

This study measures the brightness temperatures of the four main Galactic radio-loops at 22 MHz, analyzes their spectra, and finds non-thermal spectral indices, contributing to understanding their emission mechanisms.

Contribution

It provides new measurements of brightness temperatures at 22 MHz and presents spectral indices for the Galactic radio-loops, enhancing previous spectral data.

Findings

Brightness temperatures at 22 MHz for all loops.

Non-thermal spectral indices confirmed for all loops.

Spectral indices are slightly shallower than previous measurements.

Abstract

The average brightness temperatures and surface brightnesses at 22 MHz are derived for the four main Galactic radio-continuum loops (Loops I, II, III and IV, hereafter radio-loops). Also the radio-continuum spectra for the radio-loops are presented. Adding the average brightness temperatures at 22 MHz derived here with the average brightness temperatures derived from spectra published previously at 408, 820 and 1420 MHz we obtained clearly non-thermal spectral indices for all radio-loops. Our derived spectral indices are slightly shallower than those measured by previous works.