[MRF99] CLASS B1152+199 C , the SIMBAD biblio

The third phase of the Cosmic Lens All-Sky Survey (CLASS) has recently been completed, bringing the total number of sources imaged to over 15,000 in the CLASS and Jodrell-VLA Astrometric Survey combined survey. In the VLA observations carried out in 1998 March and April, two new candidate lensed systems were discovered: CLASS B1152+199 and B1359+154. B1152+199 is a 1".6 double, with a background quasar at z=1.019 lensed by a foreground galaxy at z=0.439. The relatively flat radio spectra of the lensed images (α^14.94_8.46=-0.32), combined with a previous ROSAT detection of the source, make B1152+199 a strong candidate for time delay studies at both radio and X-ray wavelengths. B1359+154 is a quadruply lensed quasar at z=3.235, with a maximum image separation of 1".7. As yet, the redshift of the lensing object in this system is undetermined. The steep spectral index of the source (α^14.94_8.46=-0.9) suggests that B1359+154 will not exhibit strong variability and is therefore unlikely to be useful for determining H₀ from measured time delays.