A test of the asteroseismic numax scaling relation for solar-like oscillations in main-sequence and sub-giant stars

TL;DR

This study tests the validity of the asteroseismic scaling relation for $ u_{ m max}$ in solar-like stars, confirming it holds within 1.5% across a broad temperature range using Kepler data.

Contribution

The paper provides the first large-scale empirical validation of the $ u_{ m max}$ scaling relation for main-sequence and sub-giant stars, confirming its accuracy within 1.5%.

Findings

The $ u_{ m max}$ scaling relation holds within 1.5% accuracy.

No significant temperature dependence found in the scaling relation.

Results support the use of the relation for stellar property estimation.

Abstract

Large-scale analyses of stellar samples comprised of cool, solar-like oscillators now commonly utilize the so-called asteroseismic scaling relations to estimate fundamental stellar properties. In this paper we present a test of the scaling relation for the global asteroseismic parameter $\nu_{\rm max}$, the frequency at which a solar-like oscillator presents its strongest observed pulsation amplitude. The classic relation assumes that this characteristic frequency scales with a particular combination of surface gravity and effective temperature that also describes the dependence of the cut-off frequency for acoustic waves in an isothermal atmosphere, i.e., $\nu_{\rm max} \propto gT_{\rm eff}^{-1/2}$. We test how well the oscillations of cool main-sequence and sub-giant stars adhere to this relation, using a sample of asteroseismic targets observed by the NASA \emph{Kepler} Mission. Our results, which come from a grid-based analysis, rule out departures from the classic $gT_{\rm eff}^{-1/2}$ scaling dependence at the level of $\simeq 1.5\,\rm per cent$ over the full $\simeq 1560\,\rm K$ range in $T_{\rm eff}$ that we tested. There is some uncertainty over the absolute calibration of the scaling. However, any variation with $T_{\rm eff}$ is evidently small, with limits similar to those above.