Dr. Sarah Pearson

Astrophysicist, Science Communicator & Public Speaker

-PhD commencement 2018, Columbia

Academic career

Sarah has published scientific papers [see ADS link] in numerous journals, and her science covers a broad range of topics such as galactic collisions, stellar streams, stellar explosions and dark matter. Her publications have been cited more than 500 times, and she has given invited talks at Harvard, MIT, the Institute for Advanced Study, Princeton and several other institutions. Additionally, she has also won awards for her research one of which was the Danish Women in Physics Prize.


Sarah obtained her Bachelor’s degree in Physics from the University of Copenhagen in 2012, after which she acquired her Master’s and PhD degrees in Astronomy from Columbia University in 2015 and 2018, respectively. Currently, she holds a NASA Hubble Fellowship at New York University, where she studies galactic dynamics, dark matter and the Galactic bar.

Research interests

Stellar streams
Stellar streams emerge, in part, from disrupting clusters of stars. Sarah showed that the shape of the dark matter mass distribution in the Milky Way can be distinguished based on the morphology of stellar streams. Streams spread much further in space on mildly chaotic orbits. Sarah dubbed this mechanism stream-fanning in her Pearson et al. (2015) article in the Astrophysical Journal. Sarah has since shifted her interest to extragalactic stellar streams and what these can teach us about dark matter. In Pearson et al. (2022b), she developed a novel extragalactic stream-fitting technique and used the straight stream near Cen A, to place limits on Cen A's dark matter halo mass. In Pearson et al. (2019), Sarah and her collaborators demonstrated that thin stellar streams from globular cluster will be observable in at least 200 nearby galaxies with NASA's Nancy Grace Roman Space Telescope, and in Pearson et al. (2022a), she developed the "Hough Stream Spotter" code to find these thin streams in external galaxies. These thin extragalactic streams can hopefully help in the quest for the nature of dark matter.

Colliding galaxies
Sarah has been involved in observational (Pearson et al. (2016), Privon, Pearson+ 2017, Luber, Pearson+ 2022) and theoretical (Pearson et al. 2018, Besla, Pearson+ 2018) studies on the nature of collisions between dwarf galaxies. The motivation for investigating this population of galaxies, is to better understand how galaxies build up their mass in the early Universe, and how they cycle through their matter today.

The Galactic Bar
In recent years, Sarah has become interested in galactic bars. In her Pearson et al. (2017) publication in Nature Astronomy, she showed that bars can punch holes in stellar streams. The signature of those events, is similar to the signature predicted from dark matter subhalos passing close by stellar streams. She is now working on several projects related to understanding the formation and evolution of galactic bars (see e.g. Lucey, Pearson et al. 2022, Bonaca, Pearson et al. 2020).

Scientific journal articles

First & second author [ADS link]

24. Mapping Dark Matter with Extragalactic Stellar Streams: the Case of Centaurus A
Pearson, S., Price-Whelan, A., Hogg, D. et al. 2022, Accepted to ApJ, arXiv: 2205.12277

23. Constraining the length and pattern speed of the Milky Way bar from direct orbit integration of APOGEE and Gaia data
Lucey, M., Pearson, S., Hunt, J. et al. 2022, submitted to MNRAS, arXiv: 2206.01798

22. Bar formation and destruction in the FIRE2 simulations
Ansar, S., Pearson, S., Sanderson, R. et al. 2022, submitted to AAS journals

21. Walter: A Tool for Predicting Resolved Stellar Population Observations with Applications to the Roman Space Telescope
Lancaster, L., Pearson, S., Williams, B. et al. 2022, AJ, 164, 4, 142, arXiv: 2207.02208

20. Investigating the Baryon Cycle in Interacting Dwarfs with the Very Large Array and Pan-STARRS
Luber, N., Pearson, S., Putman, M. E., Besla, G. et al. 2022, AJ, 163, 49 arXiv: 2111.04795

19. The Hough Stream Spotter: A new method for detecting linear structure in resolved stars and application to the stellar halo of M31
Pearson, S., Clark, S. E., Dimirjian, A. J., Johnston, K. V. et al. 2022, ApJ, 926, 166 arXiv: 2107.00017

18. Variations in the width, density, and direction of the Palomar 5 tidal tails
Bonaca, A., Pearson, S., Price-Whelan, A. et al. 2020, ApJ, 889, 70, arXiv: 1910.00592

17. Detecting Thin Stellar Streams in External Galaxies: Resolved Stars & Integrated Light
Pearson, S., Starkenburg, T., Johnston, K. V., Williams., B., and Ibata., R., 2019, accepted to ApJ, arXiv: 1906.03264

16. Modeling the Baryon Cycle in Dwarf Galaxy Encounters: the Case of NGC4490 & NGC4485
Pearson, S., Privon, G., Besla, G., Putman, M. E., Martinez-Delgado, D., Johnston, K. V., Gabany, J. R., Patton, D. R., Kallivayalil, N. 2018, MNRAS, 480, 3069, arXiv: 1807.03791

15. Gaps and Length Asymmetry in the Stellar Stream Palomar 5 as Eects of Galactic Bar Rotation
Pearson, S., Price-Whelan, A. M., Johnston, K. V. 2017, Nature Astronomy, 1, 9 arXiv: 1703.04627

14. Local Volume TiNy Titans: Gaseous Dwarf-Dwarf Interactions in the Local Universe
Pearson, S., Besla, G., Putman, M. E., Lutz, K., Fernandez, X., Stierwalt, S., Patton, D. R. et al. 2016, MNRAS, 459, 1827, arXiv: 1603.09342

13. Tidal Stream Morphology as an Indicator of Dark Matter Halo Geometry: the Case of Palomar 5
Pearson, S., Kupper, A. H. W., Johnston, K. V., A. M. Price-Whelan, 2015, ApJ, 799, 1, arXiv: 1410.3477

12. Unraveling the Origin of Overionized Plasma in the Galactic Supernova Remnant W49B
Lopez, L. A., Pearson, S., Ramirez-Ruiz, E., Castro, D., Yamaguchi, H., Slane, P., Smith, R. 2013, ApJ, 764, 50, arXiv: 1309.1464

Other journal articles

11. New Velocity Measurements of NGC 5128 Globular Clusters out to 130 kpc: Outer Halo Kinematics, Substructure and Dynamics
Hughes, Sand, [9 auhors], Pearson, S., [3 authors], 2022, submitted to ApJ, arXiv: 2208.08997

10. Separatrix Divergence II: Stream Fanning and Bifurcations: Observable Signatures of Resonances in Stellar Stream Morphology
Yavetz, T., Johnston, K. V., Pearson, S., Price-Whelan, A. et al., 2022, submitted to AAS journals

9. Once in a Blue Stream: Detection of Recent Star Formation in the NGC 7241 Stellar Stream with MEGARA
Martinez-Delgado, D., [8. authors], Pearson, S., [16. authors], 2021, submitted to MNRAS, arXiv: 2112.07029

8. Hidden Depths in the Local Universe: the Stellar Stream Legacy Survey
Martinez-Delgado, D., [4. authors], Pearson, S., [17. authors], 2021, submitted to MNRAS, arXiv: 2104.06071

7. Separatrix Divergence of Stellar Streams in Galactic Potentials
Yavetz, T., Johnston, K. V., Pearson, S., Price-Whelan, A., Weinberg, M., 2021, MNRAS, 501, 1791, arXiv: 2011.11919

6. Kinematics of the Palomar 5 stellar stream from RR Lyrae stars
Price-Whelan, A., Mateu, C., Iorio, G., Pearson, S., Bonaca, A., Belokurov, V., 2019, AJ, 158, 223, arXiv: 1910.00595

5. The Frequency of Dwarf Galaxy Multiples at Low Redshift in SDSS vs. Cosmological Expectations
Besla, G., Patton, D. R., Stierwalt, S., Rodriguez-Gomez, V., Patel, E., Kallivayalil, N. J., Johnson, K. E., Pearson, S., Privon, G. C.; Putman, M. E., 2018, MNRAS, 480, 3376, arXiv: 1807.06673

4. A Widespread, Clumpy Starburst in the Ongoing Isolated Dwarf Galaxy Merger DM1647+21
Privon, G., Stierwalt, S., Patton, D. R., Besla, G., Pearson, S., Putman, M., Johnson, K. E., Kallivayalil, N., Liss, S., 2017, ApJ, 846, 74, arXiv: 1708.02587

3. Evidence of Fanning in the Ophiuchus Stream
Sesar, B., Price-Whelan, A. M., Cohen, J. G., Rix, H. W., Pearson, S., Johnston, K. V., Bernard, E. J., Ferguson, A. M. N., Martin, N. F., Slater, C. T., Chambers, K. C., Flewelling, H., Wainscoat, R. J., Waters, C., 2016, ApJL, 816, 1, L4, arXiv: 1512.00469

2. Chaotic Dispersal of Tidal Debris
Price-Whelan, A., Johnston, K. V., Valluri, M., Pearson, S, Küpper, A. H. W., Hogg, D. W., 2016, MNRAS, 455, 1079, arXiv: 1507.08662

1. The Galactic Supernova Remnant W49B Likely Originates from a Jet-Driven Core-Collapse Explosion
Lopez, L. A., Ramirez-Ruiz, E., Castro, D., Pearson, S. 2013, ApJ, arXiv: 1301.0618