The Bayesian Asteroseismology data Modeling pipeline and its application to $\it K2$ data

TL;DR

The BAM pipeline automates the analysis of photometric time-series data to extract asteroseismic parameters, especially tailored for K2 data, and successfully identifies solar-like oscillators with high accuracy.

Contribution

We introduce BAM, a novel automated pipeline for asteroseismology that effectively processes K2 light curves and determines stellar oscillation parameters with high precision.

Findings

BAM achieves ~1.5% accuracy in oscillation parameters.

Identifies 104 new red giant solar-like oscillators in K2 data.

Estimates high purity in dwarf star selection among proposals.

Abstract

We present the Bayesian Asteroseismology data Modeling (BAM) pipeline, an automated asteroseismology pipeline that returns global oscillation parameters and granulation parameters from the analysis of photometric time-series. BAM also determines if a star is likely to be a solar-like oscillator. We have designed BAM to specially process ${\it K2}$ light curves, which suffer from unique noise signatures that can confuse asteroseismic analysis, though it may be used on any photometric time series --- including those from ${\it Kepler}$ and ${\it TESS}$. We demonstrate the BAM oscillation parameters are consistent within $\sim 1.53\%\ (\mathrm{random}) \pm 0.2\%\ (\mathrm{systematic})$ and $1.51\%\ (\mathrm{random}) \pm 0.6\%\ (\mathrm{systematic})$ for $\nu_{\mathrm{max}}$ and $\Delta \nu$ with benchmark results for typical ${\it K2}$ red giant stars in the ${\it K2}$ Galactic Archaeology Program's (GAP) Campaign 1 sample. Application of BAM to $13016$ ${\it K2}$ Campaign 1 targets not in the GAP sample yields $104$ red giant solar-like oscillators. Based on the number of serendipitous giants we find, we estimate an upper limit on the average purity in dwarf selection among C1 proposals is $\approx 99\%$, which could be lower when considering incompleteness in BAM detection efficiency, and proper motion cuts specific to C1 Guest Observer proposals.