Measuring Infrared Surface Brightness Fluctuation Distances with HST WFC3: Calibration and Advice

TL;DR

This paper provides new near-infrared surface brightness fluctuation calibrations for HST WFC3/IR, enabling precise distance measurements to elliptical galaxies up to 80 Mpc, and discusses population effects on calibration scatter.

Contribution

It introduces new IR SBF calibrations for WFC3/IR based on a diverse galaxy sample, improving distance measurement accuracy and applicability.

Findings

Calibration scatter is about 0.10 mag, corresponding to 5% distance error.

Distance measurement precision allows for 80 Mpc reach with single-orbit observations.

Population differences affect calibration scatter, especially in dwarf galaxies.

Abstract

We present new calibrations of the near-infrared surface brightness fluctuation (SBF) distance method for the F110W (J) and F160W (H) bandpasses of the Wide Field Camera 3 Infrared Channel (WFC3/IR) on the Hubble Space Telescope. The calibrations are based on data for 16 early-type galaxies in the Virgo and Fornax clusters observed with WFC3/IR and are provided as functions of both the optical (g-z) and near-infrared (J-H) colors. The scatter about the linear calibration relations for the luminous red galaxies in the sample is approximately 0.10 mag, corresponding to a statistical error of 5% in distance. Our results imply that the distance to any suitably bright elliptical galaxy can be measured with this precision out to about 80 Mpc in a single-orbit observation with WFC3/IR, making this a remarkably powerful instrument for extragalactic distances. The calibration sample also includes much bluer and lower-luminosity galaxies than previously used for IR SBF studies, revealing interesting population differences that cause the calibration scatter to increase for dwarf galaxies.