@article{2055b16a8603401e9e15b4341918bf2f,
title = "The carnegie-Chicago hubble program. IX. Calibration of the tip of the red giant branch method in the megamaser host galaxy, NGC 4258 (M106)",
abstract = "In the nearby galaxy NGC 4258, the well-modeled orbital motion of H2O masers about its supermassive black hole provides the means to measure a precise geometric distance. As a result, NGC 4258 is one of a few “geometric anchors” available to calibrate the true luminosities of stellar distance indicators such as the Tip of the Red Giant Branch (TRGB) or the Cepheid Leavitt law. In this paper, we present a detailed study of the apparent magnitude of the TRGB within NGC 4258, using publicly available HST observations optimally situated in the unreddened stellar halo along the minor axis, spanning distances ranging from 8 to 22 kpc in projected galactocentric radius, or 6¢ (13 kpc) to 30¢ (66 kpc) in distance along the semimajor axis. We undertake a systematic evaluation of the uncertainties associated with measuring the TRGB in this galaxy, based on an analysis of 54 arcmin2 of HST/ACS imaging. After quantifying these uncertainties, we measure the TRGB in NGC 4258 to be F814W0 = 25.347 ± 0.014 (stat) ± 0.042 (sys) mag. Combined with a recent 1.5% megamaser distance to NGC 4258, we determine the absolute luminosity of the TRGB to be MF814WTRGB = -4.050 ± 0.028 (stat) ± 0.048 (sys) mag. This new calibration agrees to better than 1% with an independent calibration presented in Freedman et al. that was based on detached eclipsing binaries (DEBs) located in the LMC.",
author = "Jang, {In Sung} and Hoyt, {Taylor J.} and Beaton, {Rachael L.} and Freedman, {Wendy L.} and Madore, {Barry F.} and Lee, {Myung Gyoon} and Neeley, {Jillian R.} and Monson, {Andrew J.} and Rich, {Jeffrey A.} and Mark Seibert",
note = "Funding Information: Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS website is www.sdss.org. Funding Information: Support for program #13691 (PI W. L. Freedman) was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. Support for this work was also provided by NASA through Hubble Fellowship grant #51386.01 awarded to R. L. B. by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. M. G. L. is supported by a grant from the National Research Foundation (NRF) of Korea, funded by the Korean Government (NRF-2019R1A2C2084019). Funding Information: Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. Publisher Copyright: {\textcopyright} 2021. The American Astronomical Society. All rights reserved.",
year = "2021",
month = jan,
day = "10",
doi = "10.3847/1538-4357/abc8e9",
language = "English (US)",
volume = "906",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",
}