Confirmation of two extended objects along the line of sight to PKS 1830-211 with ESO-VLT adaptive optics imaging

Abstract

We report on new high-resolution near-infrared images of the gravitationally lensed radio source PKS 1830-211, a quasar at z = 2.507. These adaptive optics observations, taken with the Very Large Telescope (VLT), are further improved through image deconvolution. They confirm the presence of a second object along the line of sight to the quasar, in addition to the previously known spiral galaxy. This additional object is clearly extended in our images. However, its faint luminosity does not allow to infer any photometric redshift. If this galaxy is located in the foreground of PKS 1830-211, it complicates the modeling of this system and decreases the interest in using PKS 1830-211 as a means to determine H0 via the time delay between the two lensed images of the quasar. © ESO 2005.