Comparative Bayesian SED Fitting of PEARLSDG

Abstract

The initial distance to PEARLSDG estimated from the Tip of the Red Giant Branch suggested it was an exotic isolated quiescent dwarf galaxy. We combine recent and archival Hectospec spectroscopy to place it at $z=0.02843\pm 0.00012$ ($D\approx 124$\,Mpc) within a galaxy group, revising the distance from 30\,Mpc to $\sim$124\,Mpc. We then carry out {\sc Prospector} SED fitting using parametric and non-parametric star-formation histories sampled with \texttt{dynesty}, \texttt{nautilus}, and \texttt{emcee}, recovering metallicity $\log (Z/Z_{\odot })=-0.44_{-0.06}^{+0.35}$, stellar mass ${\log }_{10}(M_{\ast }/M_{\odot })=9.25_{-3.73}^{+0.02}$, and dust attenuation ${\hat{\tau }}_V=0.67_{-0.05}^{+0.02}$. The updated metallicity places PEARLSDG squarely on the standard mass--metallicity relation, resolving its former outlier status, with its quenched star-formation history consistent with environmental quenching in a group setting.

References in corpus (7)

• emcee: The MCMC Hammer
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• The propagation of uncertainties in stellar population synthesis modeling I: The relevance of uncertain aspects of stellar evolution and the IMF to the derived physical properties of galaxies
• Modeling the Panchromatic Spectral Energy Distributions of Galaxies
• Stellar Population Inference with Prospector
• Physical properties and environments of nearby galaxies