Tianqing Zhang

About Me

I am an observational cosmologist. I use large extragalactic datasets from the Subaru Telescope, Rubin Observatory, and Nancy Grace Roman Space Telescope to study the structure of the universe, nature of dark matter and dark energy. I use techniques such as the weak gravitational lensing and galaxy clustering, etc. I particularly study observational systematics that can impact these analysis, such as the Point Spread Function (PSF) and the photometric redshift (photo-z).

I am Research Assistant Professor at University of Pittsburgh and a LINCC Frameworks research scientist. Previously, I was a graduate student at McWilliams Center for Cosmology, Carnegie Mellon University. I did my undergrad at Duke University and Shanghai Jiao Tong University. I have been passionate about Astronomy since 15.

I am based in Pittsburgh, PA. Sometimes I show up in the Bay Area, California.

Outside of research, I like to hike, build Astronomy community, and play low-intensity basketball...

🎃 🎃 🎃

Tannoudji

Point Reyes, CA

Credit: Jocelyn Zhang

Research

My research studies weak gravitational lensing and utilize statistical and machine learning methods to extract information from large photometric survey dataset such as the Vera R. Observatory's LSST, the Subaru Telescope's Hyper Suprime-Cam (HSC), and Roman Space Telescope's High Latitude Imaging Survey.

Point Spread Function (PSF)

I study how the atmospheric turbulence and optical effect, normal described as the Point Spread Function (PSF), impact weak lensing measurement. Especially, I study how higher moments of the PSF impact the shear estimation.

[Paper I] [Paper II] [Paper III]

My higher moments measurement algorithm is also implemented as part of the Rubin Science Pipeline.

Image Simulation

I extensively apply image simulation based on GalSim in my research.

Weak Lensing Cosmology

I am involved in the HSC Y3 weak lensing cosmology analysis . I am in charge of the PSF-related null tests for the shear catalog, and is involved in the cosmic shear analysis. Later, I developed point-mass correction and redshift self-calibration model, and applied the method to the HSC Y3 2x2pt and 3x2pt analysis.

Bayesian Weak Lensing Inference

I developed a Bayesian weak lensing inference framework to fully marginalize the uncertainty of the photometric redshift distribution of the shear catalog.

Cosmic Proper Motion

I work with Pitt undergrad Sean Maloney on measuring the earth movement using GAIA extragalactic catalogs.

Contact

Email: tq96zhang at gmail.com