Amanda Quirk


    I am a third year graduate student working with Prof. Puragra Guha Thakurta on the kinematics of stars and gas in the Andromeda galaxy and in the Triangulum galaxy. I am particularly interested in what asymmetric drift can tell us about the dynamical heating history of a galaxy.

I graduated with a Bachelor’s of Arts in astrophysics from Columbia University in 2017. There I worked with Prof. Jeremiah Ostriker and Dr. Ena Choi on galaxy evolution. We used zoom-in hydrodynamical simulations to study the effects of supernova feedback on low mass stellar halos and dark matter halos.

I also am an advocate for individuals with disabilities and am working on increasing awareness and accessibility in the department. I plan to have a career in STEM outreach and education and focus on increasing accessibility for more students.

M31 image credit: Robert Gendler


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    I am using HST data from the PHAT survey and spectroscopy from Keck/DEIMOS in the SPLASH survey to study asymmetric drift as a function of stellar age in M31’s disk. Asymmetric drift is the difference between the circular rotation velocity of the stars and that of the gas. I find that asymmetric drift increases with stellar age, which reflects the violent and continuous merger history that M31 is believed to have had. The figure below shows how asymmetric drift changes with stellar age. The results of this study can be found published here!

Thanks to a successful observing run  in the Fall of 2018, I aim to do a comparison study in M33. 

    One of my goals is to explore what asymmetric drift can tell us about the dynamical heating history of a galaxy, whether internal: bars, spiral waves, giant molecular clouds or external: mergers. To do this, I have turned to simulations. I am currently studying simulated galaxies from Illustris that have a wide range of merger histories. I am looking at how trends with asymmetric drift change passed on various merger history parameters.

    With Prof. Ostriker and Dr. Choi, I analyzed dark matter halos in zoom-in hydrodyamical cosmological simulations. Specifically I examined dark matter subhalos that were void of significant stellar and gas mass at redshift zero. The image below shows the location at z=0 of one of these “dark subhalos,” which is circled in white.

Here I am touring Keck II and DEIMOS before our Fall 2018 observing run of M33.


    I am involved in several outreach organizations in Santa Cruz. As a member of WiPA (Women in Physics and Astronomy), I mentor undergraduate students at UCSC about how to navigate courses, research, and life after undergrad. I am also the liaison between WiPA and WiSE (Women in Science and Engineering) and help coordinate outreach events. WiSE works with grade school students to engage them in science at an early age. As seen in the picture below, we conducted a strawberry DNA extraction with fifth graders at Elkhorn Elementary. Through Skype a Scientist, I can further spread my love of astronomy to classrooms and community programs nationwide. Additionally, I am a volunteer teacher at the Santa Cruz County Jail systems through the Project for Inmate Education (PIE). There I teach astronomy and pre-algebra to inmates for college credit.

    I think the most important role of scientists is to be able to convey information to the public. Thus, I am committed to increasing both intellectual and physical accessibility in science.  I am a graduate student assistant at UCSC’s Disability Research Center, where I am creating campaigns and community programs for students who identify as having a disability. Through this role, I created and run the Graduate Disability Community Group. I am also the PI of an Osterbrock Leadership Program-sponsored grant to create a workshop for on accessible teaching and classroom practices. Through this role, I am educating myself about Universal Design for Learning (UDL) and what resources are available to educators to make classrooms more accessible to students. I practice implementing UDL through my TAing and teaching with PIE.


    I am also working with several undergraduate students at UCSC. In 2018 and 2019 I co-mentored a group of students for Introduction to Research. In this class, students learn Python and the steps of a research project while working in small groups with a graduate student, post doc, or faculty member. Each group of students completes a research project. Below is a photo of my 2019 group standing in front of the poster they made for their project that examined rare stars in M31 and M33. 


AGN-Driven Quenching of Satellite Galaxies: G. Dashyan, E. Choi, R. S. Somerville, T. Naab, A. C. N. 

    Quirk, M. Hirschmann, J. P. Ostriker MNRAS (arXiv:1906.07431)

Nebular Spectroscopy of Kepler's Brightest Supernova: G. Dimitriadis, C. Rojas-Bravo, C. D. Kilpatrick, 

    R. J. Foley, A. L. Piro, J. S. Brown, P. Guhathakurta, A. C. N. Quirk , A. Rest, G. M. Strampelli, B. E. 

    Tucker, and A. Villar 2018 –  ApJL (arXiv:1812.00097

Asymmetric Drift in M31: A. C. N. Quirk, P. Guhathakurta, L. Chemin, et al. 2018 – ApJ  vol 871

    (arXiv: 1811.07037

Mergers in the Illustris Simulation: G. F. Snyder, V. Rodriguez-Gomez , J. M. Lotz, Paul Torrey, A. C. N.     

        Quirk, L. Hernquist, M. Vogelsberger, P. E. Freeman 2018 – MNRAS (arXiv:1809.02136)