Near-Infrared Observations of OGLE Classical and Type II Cepheid Variables in the LMC
Abstract
This poster presented results from the Large Magellanic Cloud Near-Infrared Synoptic Survey (LMCNISS) for classical and Type II Cepheid variables that were identified in the Optical Gravitational Lensing Experiment (OGLE-III) catalogue. Multi-wavelength time-series data for classical Cepheid variables are used to study light-curve structures as a function of period and wavelength. We exploited a sample of ~1400 classical and ~80 Type II Cepheid variables to derive Period-Wesenheit relations that combine both optical and near-infrared data. The new Period-Luminosity and Wesenheit relations were used to estimate distances to several Local-Group galaxies (using classical Cepheids) and to Galactic globular clusters (using Type II Cepheids). By appealing to a statistical framework, we found that fundamental-mode classical Cepheid Period-Luminosity relations are non-linear around 10-18 days at optical and near-IR wavelengths. We also suggested that a non-linear relation provides a better constraint on the Cepheid Period-Luminosity relation in Type Ia Supernovæ host galaxies, though it has a negligible effect on the systematic uncertainties affecting the local measurement of the Hubble constant.
- Publication:
-
Southern Horizons in Time-Domain Astronomy
- Pub Date:
- August 2019
- DOI:
- 10.1017/S1743921318002776
- arXiv:
- arXiv:1806.06528
- Bibcode:
- 2019IAUS..339..283B
- Keywords:
-
- Stars: variables: Cepheids;
- galaxies: Magellanic Clouds;
- cosmology: distance scale;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 4 Pages, 2 figures, Proceedings IAU Symposium No. IAUS 339, 2018, Southern Horizons in Time-Domain Astronomy, Talk @OGLE25 workshop