Amanda Quirk

M31 image credit: Robert Gendler


    I am a third year PhD candidate in the Astronomy & Astrophysics department at UCSC. I’m 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 and the velocity ellipsoid 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 with a focus on increasing accessibility for students. 


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   For my first project at UCSC, I used Hubble Space Telescope 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 found 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 now have data from stars across the entire disk of the Triangulum Galaxy (M33) and aim to do a comparison study to the work above. The data I have been using and have collected myself comes from the summit of Mauna Kea. I want to acknowledge the significance and the importance of this land to the Hawaiian community and say I am appreciative of being able to use data from such a sacred place. 

    One of my larger science 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 the Illustris simulation that have a wide range of merger histories. I am looking at how trends with asymmetric drift change based on various merger history parameters. The plot below summarizes my findings. I’ve found that M31-like analogs that have experienced a major merger recently have higher asymmetric drift than analogs that have not had a recent major merger. In fact, the asymmetric drift I observed in M31’s disk nicely matches the analogs with mergers, which is a potential piece of evidence that M31 has had a major merger within the past 4 billion years! You can read more about this result here.

    With Prof. Ostriker and Dr. Choi during my undergrad, 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.


    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 have also been 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 left picture below, we conducted a strawberry DNA extraction with fifth graders at Elkhorn Elementary. Through Skype a Scientist (picture below on the right) and Letters to a Pre-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 now am co-director of the program.

    I think the most important role of scientists is to be able to convey information to others. Thus, I am committed to increasing both intellectual and physical accessibility in science.  I spent time as a graduate student assistant at UCSC’s Disability Research Center, where I created campaigns and community programs for students who identify as having a disability. Through this role, I created and run the Graduate Disability Community Group, which gives grad students a safe space to discuss their experiences as someone with a disability, gain support, and develop a community that was previously missing from campus. 

    I am also the PI of an Osterbrock Leadership Program sponsored grant to create a workshop on accessible teaching and best classroom practices. As a part of my project, I am educating myself about Universal Design for Learning (UDL) and what resources are available to educators to make classrooms more accessible to students. Here is a presentation I made with some UDL guidelines and online resources (some are specific to UCSC). I practice implementing UDL through my TAing and teaching with PIE. I am continuing to develop my teaching through UCSC’s Center for Innovation in Teaching and Learning’s Graduate Pedagogy Fellowship Program (GPF). As a fellow, I am being trained on how to teach and conduct TA training courses with a focus on inclusion and equity. I am working with the Astronomy Department to update their TA training course and will be the instructor for the course Fall 2020. 


    I am also working with several undergraduate students at UCSC. In 2018 and 2019 I co-mentored a group of students for the Astronomy Department’s 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. That summer, I worked with these students and a group of high schoolers as a part of UCSC’s Science Internship Program (SIP). They continued to look at the properties of rare stars in M33. This work is now being conducted by a UCSC undergraduate in his second year.

    I have also been involved with teaching Python to high schoolers and undergraduate students. For the past two summers, I have conducted a Python bootcamp for SIP students. This winter, I also helped the Lamat Summer Program students learn Python before their internship. Additionally, Prof. Guha Thakurta and I have been expanding a Python tutorial through an astronomy research paper to students around the world. We estimate we’ve reached over 300 students ages middle school to masters programs with Python and Research (PyAR - website coming soon!). We aim to continue to expand this tutorial to other schools and subjects.


*Asymmetric Drift in Andromeda Analogs in the Illustris Simulation: A. C. N. Quirk & E. Patel

    submitted to MNRAS (arXiv:2001.00931)

*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)

*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 2019 – MNRAS (arXiv:1809.02136) 

*Asymmetric Drift in M31: A. C. N. Quirk, P. Guhathakurta, L. Chemin, et al. 2019 – ApJ  vol 871

    (arXiv: 1811.07037

*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)

Life Outside of Work

    When I’m not working, I enjoy traveling and exploring Santa Cruz. I draw and paint when I have the time and swim to relax. My favorite activity in the world is snorkeling. I am lucky to be able to squeeze in some hours snorkeling while on observing trips. Below is a picture of a sea turtle I saw during my last trip to Hawaii! Through my travels, I have picked up some Turkish. I try to maintain my Spanish language knowledge through grad communities and outreach events run in Spanish. 


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