An Empirical Calibration of the Tip of the Red Giant Branch Distance Method in the Near Infrared. I. HST WFC3/IR F110W and F160W Filters

Understand

The Tip of the Red Giant Branch (TRGB)-based distance method in the I band is one of the most efficient and precise techniques for measuring distances to nearby galaxies (D <= 15 Mpc).

• The TRGB in the near infrared (NIR) is 1 to 2 magnitudes brighter relative to the I band, and has the potential to expand the range over which distance measurements to nearby galaxies are feasible.
• Using Hubble Space Telescope (HST) imaging of 12 fields in 8 nearby galaxies, we determine color-based corrections and zero points of the TRGB in the Wide Field Camera 3 IR (WFC3/IR) F110W and F160W filters.
• First, we measure TRGB distances in the I band equivalent Advanced Camera System (ACS) F814W filter from resolved stellar populations with the HST.