Robyn Sanderson

Robyn Sanderson
Standing Faculty

Assistant Professor


Research Areas: Astrophysics



I am an assistant professor in the Physics & Astronomy department and an Associate Research Scientist in the Center for Computational Astrophysics at the Flatiron Institute in Manhattan. My research focuses on ways to infer the dark matter distribution in galaxies by studying the orbits of their stars. I completed my Ph.D. in Physics at MIT in 2011, spent three years as a postdoc at the Kapteyn Institute in the Netherlands, and held an NSF Astronomy and Astrophysics Postdoctoral Fellowship at Columbia, NYU, and then Caltech before joining UPenn and Flatiron.


Massachusetts Institute of Technology  Cambridge, Massachusetts, USA, 2004–2011
Ph.D., Physics, 25 January 2011.
Thesis advisor: Edmund Bertschinger. Thesis Committee: Alan Guth, Paul Schechter.

University of Maryland  College Park, Maryland, USA 1999–2003
B.S., Physics, High Honors and magna cum laude
B.S., Astronomy, High Honors and magna cum laude


Research Interests

I am interested in the end-to-end connection between predictions from different particle models for the distribution of dark matter in galaxies and the observations of these galaxies that we can make today and in the future, particularly observations of the dynamics of stars in galaxy outskirts where dark matter should dominate. I am currently working with data from the Gaia mission for this purpose, and have produced mock Gaia surveys of high-resolution cosmological-hydrodynamical simulations to explore the best strategies for using this information to map the dark matter in the Milky Way. Looking to the future, I am a member of the SDSS-V consortium and the WEAVE project, whose programs will add a wealth of velocity and chemical-abundance information to Gaia's catalog, and co-chair of a working group on astrometry (measuring the positions and motions of objects on the sky) using the future Nancy Grace Roman Space Telescope (formerly WFIRST). I look forward to creating realistic projections for how we can test dark matter theories with the enormous amounts of new information promised by the next generation of observations.

Courses Taught

Fall 2021: ASTR001, Survey of the Universe
Fall 2020: ASTR001, Survey of the Universe
Fall 2018: PHYS 533, Galactic Dynamics with Gaia

Selected Publications

Sanderson, R. E., A. Wetzel, S. Loebman, S. Sharma, P.F. Hopkins, S. Garrison-Kimmel, C.-A. Faucher-Giguère, D. Kereš, and E. Quataert (2018). Synthetic Gaia surveys from the FIRE cosmological simulations of Milky-Way-mass galaxies. arXiv:1806.10564. Data from the public surveys is available on YT hub.

Sanderson, R. E., S. Garrison-Kimmel, A. Wetzel, T. Keung Chan, P. F. Hopkins, D. Kereš, I. Escala, C.-A. Faucher-Giguère, and X. Ma (2017). Reconciling observed and simulated stellar halo masses. arXiv:1712.05808. 

Sanderson, R. E., A. Bellini, & the WFIRST Astrometry Working Group (2017). Astrometry with the WFIRST Wide-Field Imager. arXiv:1712.05420. 

Sanderson, R. E., A. Secunda, K. V. Johnston, and J. J. Bochanski (2017). New views of the distant stellar halo. MNRAS 470, 5014–5031. 

Sanderson, R. E., A. Helmi, and D. W. Hogg (2015). Action-space Clustering of Tidal Streams to Infer the Galactic Potential. ApJ 801, 98. 

Sanderson, R. E. and A. Helmi (2013). An analytical phase-space model for tidal caustics. MNRAS 435, 378– 399. 

For a complete list of publications search for my ORCID: 0000-0003-3939-3297.



Associate Research Scientist, Center for Computational Astrophysics, Flatiron Institute, New York, NY



CV (file)