The VMC Survey. XIII. Type II Cepheids in the Large Magellanic Cloud

V. RIPEPI + 9 COAUTORES; A.E. PIATTI; S. SUBRAMANIAN

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 446 p. 3034 - 3061

0035-8711

The VISTA survey of the Magellanic Clouds System (VMC) is collecting deep Ks ?bandtime?series photometry of the pulsating variable stars hosted in the system formedby the two Magellanic Clouds and the Bridge connecting them. In this paper we haveanalysed a sample of 130 Large Magellanic Cloud (LMC) Type II Cepheids (T2CEPs)found in tiles with complete or near complete VMC observations for which identifi-cation and optical magnitudes were obtained from the OGLE III survey. We presentJ and Ks light curves for all 130 pulsators, including 41 BL Her, 62 W Vir (12 pWVir) and 27 RV Tau variables. We complement our near-infrared photometry with theV magnitudes from the OGLE III survey, allowing us to build a variety of Period-Luminosity (P L), Period-Luminosity-Colour (P LC) and Period-Wesenheit (P W ) re-lationships, including any combination of the V, J, Ks filters and valid for BL Her andW Vir classes. These relationships were calibrated in terms of the LMC distance mod-ulus, while an independent absolute calibration of the P L(Ks ) and the P W (Ks , V )was derived on the basis of distances obtained from Hubble Space T elescope paral-laxes and Baade-Wesselink technique. When applied to the LMC and to the GalacticGlobular Clusters hosting T2CEPs, these relations seem to show that: 1) the two pop-ulation II standard candles RR Lyrae and T2CEPs give results in excellent agreementwith each other; 2) there is a discrepancy of ∼0.1 mag between population II standardcandles and Classical Cepheids when the distances are gauged in a similar way for allthe quoted pulsators. However, given the uncertainties, this discrepancy is within theformal 1σ uncertainties.