Universal Scaling Laws for Solar and Stellar Atmospheric Heating: Catalog of Power-law Index between Solar Activity Proxies and Various Spectral Irradiances

TL;DR

This paper presents a comprehensive catalog of power-law indices linking solar activity proxies with spectral line fluxes across various atmospheric layers, aiding the understanding of magnetic heating processes in the Sun and Sun-like stars.

Contribution

It expands previous studies by including more proxies and spectral lines, enabling detailed analysis of flux-flux scaling laws across different stellar atmospheric regions.

Findings

Catalog of power-law indices for multiple proxies and spectral lines

Enhanced understanding of magnetic heating across atmospheric layers

Data supports reconstruction of stellar spectral fluxes in the past

Abstract

The formation of extremely hot outer atmospheres is one of the most prominent manifestations of magnetic activity common to the late-type dwarf stars, including the Sun. It is widely believed that these atmospheric layers, the corona, transition region, and chromosphere, are heated by the dissipation of energy transported upwards from the stellar surface by the magnetic field. This is signified by the spectral line fluxes at various wavelengths, scaled with power-law relationships against the surface magnetic flux over a wide range of formation temperatures, which are universal to the Sun and Sun-like stars of different ages and activity levels. This study describes a catalog of power-law indices between solar activity proxies and various spectral line fluxes. Compared to previous studies, we expanded the number of proxies, which now includes the total magnetic flux, total sunspot number, total sunspot area, and the F10.7 cm radio flux, and further enhances the number of spectral lines by a factor of two. This provides the data to study in detail the flux-flux scaling laws from the regions specified by the temperatures of the corona (log(T/K)=6-7) to those of the chromosphere (log(T/K)~4), as well as the reconstruction of various spectral line fluxes of the Sun in the past, F-, G-, and K-type dwarfs, and the modeled stars.