SHAO Astrophysics Colloquium

Title: Applications of Simulations of Strong Lensing in Astrophysics and Cosmology
Speaker: Nan Li  (University of Chicago and Argonne National Lab)

Time: 3:00 pm, December 19th (Thursday)

Location: Lecture Hall, 3rd floor

Abstract: 

Cosmological strong gravitational lensing probes the properties of the dense cores of dark matter halos and offers the opportunity to study the distant Universe at flux levels and spatial resolutions otherwise unavailable. However, non-linear effects in strong lenses due to substructures and line of sight structures are still unsettled.  To understand the impacts thoroughly, we have developed an image simulation pipeline, Pipeline for Images of Cosmological Strong lensing (PICS), to generate realistic strong gravitational lensing signals in galaxies, galaxy groups, and galaxy clusters. In this presentation, I will first describe the construction of PICS, then introduce several applications of PICS in astrophysics and cosmology, including 1) lensing effects on the morphological properties of background source galaxies, 2) influence of the line of sight structures on the strong lensing cross-section in galaxy clusters, and 3) how to calibrate H0 that measured by using strong lensing time-delays. Moreover, PICS is also employed to deal with "big data problems" in the era of LSST, Euclid, and CSST. I will present how to search and model strong lenses automatically and efficiently in the upcoming enormous datasets, such as tens of billions of objects, and quantify the performance of our approaches with mock data created by using PICS.