Headshot of Brian DiGiorgio Zanger

I'm a physics and astronomy professor who values the liberal arts

I teach physics and astronomy at all levels at Swarthmore College, focusing on active learning, interdisciplinary connections, and student participation. My research models irregularities in galaxy rotation using Bayesian techniques, and I have mentored undergraduates as they have learned the basics of astrophysics research. I also publish on teaching, with my articles appearing in the American Journal of Physics in 2026, and The Physics Teacher.

Work

Image showing an example barred velocity field with the Nirvana model of it, the residuals of the fit, and an image of the galaxy.

Nirvana

Nirvana is a nonparametric Bayesian forward modeling package for fitting bisymmetric disturbances in galaxy kinematics. It also includes a catalog of 1000+ kinematic models of barred galaxies from the MaNGA survey.

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A diagram showing the differential effects of lensing shear on a galaxy's kinematic and photometric information.

Kinematic Weak Lensing

Kinematic information is affected differently by weak lensing shear compared to photometric information. By modeling both the shear on the velocity field and the discrepancy between kinematics and photometry, we can significantly increase lensing information per galaxy.

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Handwritten class notes and diagrams.

Teaching

I teach introductory physics and astronomy for majors and nonmajors as well as upper-level electives, built around active learning, Universal Design, and hands-on practice. I also publish peer-reviewed work on physics pedagogy.

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Three panels showing the first- and second-order components of a galaxy's modeled velocity field.

Research with Students

I design research projects that undergraduates can carry from start to finish in a year or two. Four students have worked with me so far at Colby and Swarthmore, on bar kinematics, stellar populations, and the Tully-Fisher relation.

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A question mark with a space background.

Outreach

I run observatory public nights, taught Python and data science to summer REU students, and led UC Observatories' "Ask an Astronomer" team for five years.

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A plot comparing second-order rotational mode strengths in barred and unbarred galaxies.

Publications

Refereed papers in The Astrophysical Journal, the American Journal of Physics, and The Physics Teacher, plus work in preparation and a list of recent talks.

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