Non-Linear Convergence of Solar-like Stars Chromospheres using Millimeter, Sub-millimeter, and Infrared Observations

TL;DR

This paper introduces a new semiempirical modeling method using non-linear fitting to match observed spectra of solar-like stars across millimeter to infrared wavelengths, validated with ALMA observations of Alpha Centauri A.

Contribution

The study develops a novel non-linear fitting approach with the Levenberg-Marquardt algorithm to accurately model the chromospheres of solar-like stars using observational data.

Findings

Successfully reproduces observed spectra of Alpha Centauri A

Identifies temperature minima and plateaus in high chromosphere profiles

Provides a fast numerical tool for stellar chromosphere analysis

Abstract

In this work, we present a new methodology to fit the observed and synthetic spectrum of solar-like stars at millimeter, submillimeter and infrared wavelengths through semiempirical models of the solar chromosphere. We use the Levenberg-Marquardt algorithm as a Non-Linear method, PakalMPI as the semiempirical model of the solar chromosphere, and recent observations from the Atacama Large Millimeter/submillimeter Array (ALMA) of Alpha Centauri A as a test case. Our results show that we can use solar chromospheric semiempirical models as an input model to reproduce the observed spectrum of solar-like stars. The new profiles show similarities to the solar chromosphere as a minimum of temperature (without the restriction from CO emission) and a plateau in the high chromosphere. Our method provides a new fast numerical tool to estimate the physical conditions of solar-like stars.