English

Comparative Bayesian SED Fitting of PEARLSDG

Astrophysics of Galaxies 2026-04-07 v1

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±0.00012z = 0.02843 \pm 0.00012 (D124D \approx 124\,Mpc) within a galaxy group, revising the distance from 30\,Mpc to \sim124\,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)=0.440.06+0.35\log(Z/Z_\odot) = -0.44^{+0.35}_{-0.06}, stellar mass log10(M/M)=9.253.73+0.02\log_{10}(M_*/M_\odot) = 9.25^{+0.02}_{-3.73}, and dust attenuation τ^V=0.670.05+0.02\hat{\tau}_V = 0.67^{+0.02}_{-0.05}. 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.

Keywords

Cite

@article{arxiv.2604.03761,
  title  = {Comparative Bayesian SED Fitting of PEARLSDG},
  author = {Barış Bayraktar and Timothy Carleton and Rogier A. Windhorst and S. P. Willner and Christopher N. A. Willmer},
  journal= {arXiv preprint arXiv:2604.03761},
  year   = {2026}
}