New optical surveys for gravitationally lensed quasars

This thesis describes four new optical surveys for gravitationally lensed quasars. The goal of this work has been to (1) explore new strategies for conducting optical surveys, especially in the southern hemisphere, in the hopes of "fine-tuning" the survey techniques toward finding systems of particular scientific interest; and (2) to increase the number of optically-selected lenses, and by extension, to improve future statistical analyses of lens surveys by enlarging the sample size of quasars that have been surveyed for lensing. Optical surveys for strong lenses have the potential to discover an order of magnitude more systems than radio surveys, to produce optically-bright lenses that are well-suited for long-term monitoring and followup observations, and to yield statistical constraints on the overall geometry and dynamics of the Universe. Three of these surveys take the form of traditional "targeted" searches. These include: 1) a ground-based survey targeting 173 radio-loud quasars using the 2.4 m telescope at Michigan-Dartmouth-MIT Observatory (MDM), producing one certain lens and one binary quasar; 2) a ground-based survey targeting 377 quasars in the southern hemisphere using the 1.5 m telescope at Cerro-Tololo Interamerican Observatory (CTIO), producing two certain lenses and one binary quasar; 3) a space-based snapshot survey for close separation lenses targeting 320 quasars using the Hubble Space Telescope (HST), producing three certain lenses and maybe a fourth. The MDM survey has been designed to combine the high discovery efficiency of optical surveys with the rich image morphology often found in radio-loud lenses. The CTIO survey makes use of two new catalogs of bright quasars to provide a high discovery efficiency of 0.7%.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2002

Author dc:creator

• Morgan, Nicholas D., 1975-

Advisor dc:contributor.advisor

• Paul L. Schechter.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/29306

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/29306