Simulating radio emission from Low Mass Stars

TL;DR

This paper introduces a novel model that predicts radio emission from low-mass stars by simulating electron cyclotron maser instability based on observed magnetic maps, aiding understanding of stellar magnetism and space weather.

Contribution

The first model to predict stellar radio emission from magnetic maps using electron cyclotron maser instability, validated against real observations of V374 Peg.

Findings

Successfully fit radio observations of V374 Peg

Supported the electron cyclotron maser as the emission mechanism

Model can be extended to other stars with magnetic maps

Abstract

Understanding the origins of stellar radio emission can provide invaluable insight into the strength and geometry of stellar magnetic fields and the resultant space weather environment experienced by exoplanets. Here, we present the first model capable of predicting radio emission through the electron cyclotron maser instability using observed stellar magnetic maps of low-mass stars. We determine the structure of the coronal magnetic field and plasma using spectropolarimetric observations of the surface magnetic fields and the X-ray emission measure. We then model the emission of photons from the locations within the corona that satisfy the conditions for electron cyclotron maser emission. Our model predicts the frequency, and intensity of radio photons from within the stellar corona. We have benchmarked our model against the low-mass star V374 Peg. This star has both radio observations from the Very Large Array and a nearly simultaneous magnetic map. Using our model we are able to fit the radio observations of V374 Peg, providing additional evidence that the radio emission observed from low-mass stars may originate from the electron cyclotron maser instability. Our model can now be extended to all stars with observed magnetic maps to predict the expected frequency and variability of stellar radio emission in an effort to understand and guide future radio observations of low-mass stars.