Year: 2012
Type: dissertation
Abstract: Starting with a concise introduction on gravitational lensing, time delays between lensed quasars and its importance as a cosmological probe to estimate the Hubble constant, we present our contribution to this domain. In a first part, we explain the details of the Numerical Model Fit, a method to estimate time delays between two or more lensed quasar images. We apply this technique to the light curves of 11 lensed quasars with known time delays in order to analyse these published delays in a more homogeneous way. Some results can be confirmed, but others prove to be unreliable. The second part is devoted to the most recent results of our contribution to the COSMOGRAIL collaboration. We briefly summarize the data reduction and analysis tools before the presentation of the photometry and time delay analysis of 6 lensed quasars. On top of the confirmation of time delays in two objects, SDSS J1206+4332 and SDSS J1650+4251, we are the first to measure the time delay in three doubly lensed quasar systems: HS 2209+1914, SDSS J0903+5028, and SDSS J1155+6346. The time delay analysis of the well-known quadruply lensed quasar PG 1115+080 reveals interesting elements, and asks for further investigation of longer light curves.
Authors: E. Eulaers, Pierre Magain, Sandrine Sohy
Institution: University of Liège
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1589557826