Abstract Details
| Name: Rathnakumar S Affiliation: ARIES, Nainital Conference ID: ASI2019_478 Title : Testing simple analytical approaches to model lensed quasars through TDLMC Authors and Co-Authors : Authors: S. Rathna Kumar (1) and Hum Chand (1) Affiliations: (1) ARIES, Nainital Abstract Type : Poster Abstract Category : Extragalactic Astronomy Abstract : Strongly lensed quasars with measured time delays offer an independent method to constrain cosmological parameters, mainly $H_0$, which is complementary to other cosmological probes. Recent studies have demonstrated that it is possible to constrain $H_0$ to 3% precision from only four time delay lenses. The number of time delay lenses is growing rapidly. As the precision on $H_0$ keeps improving, it is important to ensure that the systematic errors remain sub-dominant. With the aim of assessing the present day capabilities of lens modeling codes and assumptions and to test the level of accuracy achievable on $H_0$ inference from realistic mock datasets, a group of scientists from Dark Energy Science Collaboration (DESC) have invited community members to participate in a Time Delay Lens Modeling Challenge (TDLMC), wherein they are required to model a set of simulated Hubble Space Telescope (HST) observations of 50 mock lenses. The systems are organized in three rungs with the realism and complexity of the mock lenses increasing as one goes up the ladder. The goal of the challenge is to infer $H_0$ for each rung, given HST observations, time delay measurements, and a stellar velocity dispersion measurent of the deflector, of the mock lenses in the rung, for a fixed background cosmology. The challenge is still ongoing, with Rung1 having been completed recently. We present our results for Rung1 mock systems obtained from following a simple analytical modeling approach and explore strategies for improving the precision, while keeping the systematic errors under control. |