The mid-infrared Leavitt law for classical Cepheids in the Magellanic Clouds
Abstract
The Cepheid Leavitt Law (LL), also known as the Period-Luminosity relation, is a crucial tool for assembling the cosmic distance ladder. By combining data from the OGLE-IV catalogue with mid-infrared photometry from the Spitzer Space Telescope, we have determined the 3.6 and 4.5 $\mu$m LLs for the Magellanic Clouds using ~5000 fundamental-mode classical Cepheids. Mean magnitudes were determined using a Monte Carlo Markov Chain (MCMC) template fitting procedure, with template light curves constructed from a subsample of these Cepheids with fully phased, well-sampled light curves. The dependence of the Large Magellanic Cloud LL coefficients on various period cuts was tested, in addition to the linearity of the relationship. The zero-point of the LL was calibrated using the parallaxes of Milky Way Cepheids from the Hubble Space Telescope and Gaia Data Release 2. Our final calibrated relations are M[3.6] = -3.246(±0.008)(log (P) - 1.0) - 5.784(±0.030) and M[4.5] = -3.162(±0.008)(log (P) - 1.0) - 5.751(±0.030).
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 2021
- DOI:
- 10.1093/mnras/staa3186
- arXiv:
- arXiv:2010.09784
- Bibcode:
- 2021MNRAS.500..817C
- Keywords:
-
- stars: variables: Cepheids;
- Magellanic Clouds;
- infrared: stars;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted by MNRAS, the full Cepheid catalogue accompanying this article will be available soon