A New Cepheid Distance Measurement and Method for NGC 6822
Abstract
We present a revised distance to the nearby galaxy NGC6822 using a new multi-band fit to both previously published and new optical, near- and mid-infrared data for Cepheid variables. The new data presented in this study include multi-epoch observations obtained in 3.6\um and 4.5\um with the \emph{Spitzer Space Telescope} taken for the Carnegie Hubble Program. We also present new observations in J, H and \kswith FourStar on the Magellan Baade telescope at Las Campanas Observatory. We determine mean magnitudes and present new period-luminosity relations in V, I, J, H, \ks, IRAC 3.6\um and 4.5\um. In addition to using the multi-band distance moduli to calculate extinction and a true distance, we present a new method for determining an extinction-corrected distance modulus from multi-band data with varying sample sizes. We combine the distance moduli and extinction for individual stars to determine and a true distance modulus .
Keywords
Cite
@article{arxiv.1409.6830,
title = {A New Cepheid Distance Measurement and Method for NGC 6822},
author = {Jeffrey A. Rich and S. E. Persson and Wendy L. Freedman and Barry F. Madore and Andrew J. Monson and Victoria Scowcroft and Mark Seibert},
journal= {arXiv preprint arXiv:1409.6830},
year = {2015}
}
Comments
Accepted for publication in ApJ, 25 pages, 18 figures, 1 table