Bibcode
Riess, Adam G.; Fliri, Jürgen; Valls-Gabaud, David
Referencia bibliográfica
The Astrophysical Journal, Volume 745, Issue 2, article id. 156 (2012).
Fecha de publicación:
2
2012
Revista
Número de citas
115
Número de citas referidas
97
Descripción
We present measurements of 68 classical Cepheids, most detected from the
Canada-France-Hawaii Telescope POMME Survey, with periods from 10 to 78
days observed in the near-infrared by the Panchromatic Hubble Andromeda
Treasury Program using the Wide Field Camera 3 (WFC3) on the Hubble
Space Telescope (HST). The combination of HST's resolution and the use
of near-infrared measurements provide a dramatic reduction in the
dispersion of the period-luminosity relation over the present optical,
ground-based data. Even using random phase magnitudes we measure a
dispersion of just 0.17 mag, implying a dispersion of just 0.12 mag for
mean magnitudes. The error in the mean for this relation is 1% in
distance. Combined with similar observations of Cepheids in other hosts
and independent distance determinations, we measure a distance to M31 of
μ0 = 24.38 ± 0.06(statistical) ±
0.03(systematic), 752 ± 27 kpc, in good agreement with past
measurements though with a better, 3% precision here. The result is also
in good agreement with independent distance determinations from two
detached eclipsing binaries allowing for an independent calibration of
the Cepheid luminosities and a determination of the Hubble constant.
Based on observations with the NASA/ESA Hubble Space Telescope, obtained
at the Space Telescope Science Institute, which is operated by AURA,
Inc., under NASA contract NAS 5-26555.