CLASS B1152+199 and B1359+154: Two New Gravitational Lens Systems Discovered in the Cosmic Lens All-Sky Survey
Abstract
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 (alpha^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 (alpha^14.94_8.46=-0.9) suggests that B1359+154 will not exhibit strong variability and is therefore unlikely to be useful for determining H_0 from measured time delays.
- Publication:
-
The Astronomical Journal
- Pub Date:
- June 1999
- DOI:
- 10.1086/300875
- arXiv:
- arXiv:astro-ph/9905043
- Bibcode:
- 1999AJ....117.2565M
- Keywords:
-
- COSMOLOGY: GRAVITATIONAL LENSING;
- Astrophysics
- E-Print:
- accepted for publication in The Astronomical Journal