Bibcode
DOI
Oscoz, Alejandro; Mediavilla, E.; Goicoechea, Luis Julian; Serra-Ricart, Miquel; Buitrago, J.
Referencia bibliográfica
Astrophysical Journal Letters v.479, p.L89
Advertised on:
4
1997
Número de citas
37
Número de citas referidas
34
Descripción
We obtain the time delay between the arrival time of the A and B images
of the QSO 0957+561. The results of applying two different methods (the
discrete cross-correlation function and the dispersion estimation
technique) to the observed light curves of the A and B images are
presented. The adopted value (time delay) is of Delta tau BA = 424 +/- 3
days (1 sigma ). We have used this time delay as well as a recent
measurement of the one-dimensional velocity dispersion of the main
lensing galaxy ( sigma gal) to estimate H0. Two H0 = H0( Delta tau BA,
sigma gal) relations based on different pictures of the lens galaxy,
lead to H0 = 64 ^{+14}_{-15} km s-1 Mpc-1 (2 sigma ) (softened power-law
sphere) and H0 = 66 ^{+15}_{-14} km s-1 Mpc-1 (2 sigma ) (King profile
plus a point-mass at the center).