Colloquium on Jan. 7, 2021

Accurate Weak Lensing Measurement

Speaker: Jun Zhang (SJTU)

Venue: Video Conference

Time: 15:00 PM, Thursday, Jan. 7, 2021

Abstract:

Accurate measurement of the weak gravitational lensing signal is one of the key subjects of large scale galaxy surveys these days, as it is a direct probe of the density fluctuation of our Universe on cosmic scales. I will start by briefly reviewing the history of this subject, and the current status of the field according to my understanding. I will then introduce the Fourier_Quad pipeline, an almost full-fledged imaging processing tool right now, which can automatically generate shear catalog directly from almost raw CCD images. The Fourier_Quad algorithm is model-independent, and therefore much faster than typically model-fitting methods. I will talk about our very recent progress regarding selection effect, and present some preliminary results from the CFHTLenS and DECaLS (DR8) data.

Report PPT:  SWIFAR_Jun Zhang.ppt