Large Magellanic Cloud Near-infrared Synoptic Survey. II. The Wesenheit Relations and Their Application to the Distance Scale
Abstract
We present new near-infrared (NIR) Cepheid period-Wesenheit (P-W) relations in the LMC using time-series observations from the Large Magellanic Cloud NIR Synoptic Survey. We also derive optical+NIR P-W relations using V and I magnitudes from the Optical Gravitational Lensing Experiment. We employ our new JHKs data to determine an independent distance to the LMC of {μ }{{LMC}}\=\18.47+/- 0.07(statistical) mag, using an absolute calibration of the Galactic relations based on several distance determination methods and accounting for the intrinsic scatter of each technique. We also derive new NIR period-luminosity and Wesenheit relations for Cepheids in M31 using observations from the Panchromatic Hubble Andromeda Treasury survey. We use the absolute calibrations of the Galactic and LMC {W}J,H relations to determine the distance modulus of M31, {μ }{{M31}}\=\24.46+/- 0.20 mag. We apply a simultaneous fit to Cepheids in several Local Group galaxies covering a range of metallicities (7.7\lt 12+{log}[{{O}}/{{H}}]\lt 8.6 dex) to determine a global slope of -3.244 ± 0.016 mag dex-1 for the {W}J,{Ks} relation and obtain robust distance estimates. Our distances are in good agreement with recent TRGB based distance estimates and we do not find any evidence for a metallicity dependence in the NIR P-W relations.
- Publication:
-
The Astronomical Journal
- Pub Date:
- April 2016
- DOI:
- 10.3847/0004-6256/151/4/88
- arXiv:
- arXiv:1510.03682
- Bibcode:
- 2016AJ....151...88B
- Keywords:
-
- Local Group;
- Magellanic Clouds;
- stars: variables: Cepheids;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 16 pages, 8 figures, Accepted for publication in The Astronomical Journal