I'm Kate Storey-Fisher (she/her), a Kavli Fellow at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford. I am in Prof. Risa Wechsler's Galaxy Formation & Cosmology group, and will also collaborate with researchers across KIPAC and the university. Previously I was a postdoc at the Donostia International Physics Center (DIPC) in Donostia-San Sebastián, Spain, working with Prof. Raúl Angulo. I completed my PhD advised by Prof. David W. Hogg at the Center for Cosmology and Particle Physics at New York University where I was a NASA FINESST fellow.

I study the large-scale structure of the universe—how we can use observations of galaxies and other astronomical objects to understand fundamental cosmological properties. More broadly, I’m interested in the application of data science and statistics to astrophysical problems.

I am also a writer, a public science educator, an open source advocate, a labor organizer, a half-marathoner, a cyclist (for commuting and for fun), and a vocal proponent of getting enough sleep.

Research

I primarily work on developing new data science methods for large-scale structure analysis, to better constrain cosmological parameters and understand the galaxy–halo connection. You can find my publications on SAO/NASA ADS and the arXiv. These are a few of my current and recent projects:

The Quaia Quasar Catalog
The Gaia mission incidentally observed 6.6 million quasar candidates! Combining this with WISE data, we contructed a quasar catalog for large-scale structure cosmology, Quaia. Check out our analyses with Quaia, including measuring S8 and the matter-radiation equality scale in cross-correlation with CMB lensing. And check out this nifty animation.
Emulation of Clustering Statistics
With the Aemulus collaboration, I have developed Gaussian process emulators to model galaxy clustering statistics in order to extract small-scale information. I investigated emulating beyond-standard statistics, such as the marked correlation function, to further constrain the growth of structure (spoiler, we get more precise constraints!). Check out our paper.
SBI for Galaxy Clustering
With the BACCO group at DIPC, I am generating a library of mock galaxy catalogs for simulation-based inference (SBI) for galaxy clustering. We are using the map2map full-field emulator and the hybrid bias expansion to model galaxy bias, which we will marginalize over to infer cosmology. The goal is to quantify the information in the galaxy field; stay tuned!
Anomalous Galaxies with GANs
I applied generative adversarial networks (GANs) to detect anomalous images in the Hyper-Suprime Cam survey. Using a novel method for anomaly characterization, we found galaxy mergers, tidal features, extreme star-formers, and even some unexplainable objects. Read about it here, and find more https://weirdgalaxi.es yourself!
Equivariant ML for Cosmology
My collaborators have developed a new approach for enforcing physical symmetries in machine learning tasks by constructing invariant scalars from geometric objects, which greatly improves performance. We are currently applying the approach to DM halos in cosmological simulations to learn their relationship to galaxy properties.
Continuous 2-Point Functions
I developed a new estimator for galaxy clustering that is continuous in galaxy separation, and any other property (binning is sinning!). It is a generalization of the 2-point correlation function that projects the pairs onto any set of basis functions, inspired by linear least-squares fitting. Check out the paper and the code, suave.

Updates

Upcoming

Recent

  • April 2025: Our paper on measuring primordial non-Gaussianity in Quaia, led by my collaborators Giulio Fabbian and David Alonso, was posted to arXiv!
  • April 2025: I made the arduous journey over to UC Berkeley and gave the BCCP Cosmology Seminar.
  • April 2025: I visited the University of Washington and gave the Astronomy Colloquium.
  • February 2025: I gave an invited talk at the Cosmology on the Steep Rise conference at the Sexten Center for Astrophysics.
  • January 2025: I gave a KIPAC tea talk on our work on Quaia.
  • December 2024: I joined DESI and attended the Collaboration Meeting in Cancún!
  • December 2024: I gave the Cosmology Seminar at the McWilliams Center at Carnegie Mellon University.
  • October 2024: Our paper on measuring the matter-radiation equality scale in Quaia, led by my collaborator David Alonso, was posted to arXiv!
  • October 2024: I helped organize, and gave a talk at, the inaugural Stanford Center for Decoding the Universe forum.
  • September 2024: I moved to the Bay Area and started as a Kavli Fellow at KIPAC at Stanford!
  • August 2024: I wrapped up my position at DIPC—but will keep collaborating with the BACCO group!
  • June 2024: I gave the seminar at IFAE, and visited both IFAE and ICE-CSIC in Barcelona.
  • May 2024: I gave the DIPC Seminar on our work on the Quaia quasar catalog.
  • February 2024: I gave the Astro Seminar at Cardiff.
  • February 2024: I gave the Cosmology Seminar at Oxford.
  • December 2023: I gave the GRAPPA colloquium at the University of Amsterdam.
  • November 2023: I attended the IX Meeting on Fundamental Cosmology in La Laguna in the Canary Islands, and visited Instituto de Astrofísica de Canarias.
  • October 2023: I started my postdoc at the Donostia International Physics Center (DIPC) with Prof. Raúl Angulo!
  • July–August 2023: I took a much-needed post-PhD break! Highly recommend.
  • June 2023: We submitted our papers on the Quaia quasar catalog and a cosmological analysis with it!
  • May 2023: I defended my PhD and became a doctor! I am so grateful to my entire community who got me here—especially my advisor, David W. Hogg. Check out my full acknowledgements (and the rest of my thesis, if you’re so inclined) here.
  • May 2023: I was invited to give a talk at the Cosmic Connections Symposium on Astrophysics x ML at the Flatiron Institute.
  • May 2023: I attended the Cosmology with the Large-Scale structure of the Universe (CosmoLSS) workshop at the Donostia International Physics Center in Donostia–San Sebastián, Spain (my future institution!).
  • April 2023: I gave a CfA seminar at the Harvard Center for Astrophysics.

For older updates, visit this page.

Writing

I have written for Astrobites, a site by graduate students that summarizes new astrophysics research papers and dishes out other astro-focused content. I have also written for the Cooper Square Review, a publication by the NYU Journalism Institute, where I completed the Science Communication Workshops. These are a few selected pieces:

The Algorithms That Rule Your Life: "Hello World" by Hannah Fry (CSR)
Drop It Like It’s Biased: A Step-by-Step Guide to Dropping the GRE (Astrobites)
Iterative Emulation is the Sincerest Form of Parameter Estimation (Astrobites)
Morpheus, God of Dreams and Morphological Galaxy Classification (Astrobites)
Queer Figures in Astronomy History (Astrobites)
Twelve Zoom Features That Would Actually Make Academia Better (CSR)

Teaching

Courses

Pedagogy

  • Spring 2019: Design Team Leader, Institute for Scientist & Engineer Educator’s Professional Development Program (ISEE PDP). Led a team to design and teach a workshop on galaxy spectroscopy at CCA.
  • Spring 2018: Participant, ISEE PDP. Designed and taught a workshop on Bayes Theorem at CCA.

Outreach

I am involved in outreach programs and events aimed at engaging the public in science and increasing the participation of underrepresented groups in STEM fields.

Science Writing Workshops
I co-led a workshop with Astrobites at AAS235 on effectively communicating science through writing, and am involved in other efforts using writing as a tool for outreach.
Skype a Scientist
I talk with classrooms of students, from 7th graders to high schoolers, about my experience as an astrophysicist via the Skype a Scientist program.
Public Talks
I give public talks on astronomy and science, to local astronomy groups and at observatories, as well as a talk at Astronomy on Tap. I have also been a guest on the comedy game show Astronaut Training at Caveat in NYC.

Service

  • I have served as a reviewer for The Astrophysical Journal (ApJ), the Journal of Cosmology and Astroparticle Physics (JCAP), the NeurIPS Machine Learning and the Physical Sciences (ML4PS) workshop, the Royal Astronomical Society Techniques & Instruments (RASTI), Publications of the Astronomical Society of Japan (PASJ), the Journal of Open Source Science (JOSS), and Citizen Science: Theory and Practice (CSTP).
  • I am on the organizing team for the Stanford Center for Decoding the Universe.
  • I served on the Science Organizing Committee of the special session Critical Challenges for Machine Learning in Astronomy at the European Astronomical Society meeting in June 2022.
  • I was the founding co-chair of the graduate student organization at NYU, G-PHORCE (Graduate Physics Organization for Research, Culture, and Education).
  • I co-organized the astro-ph journal club in the Center for Cosmology and Particle Physics (CCPP) at NYU.
  • I was on the board of the Women in Physics (WiPhy) group at NYU.

Contact me!

Feel free to get in touch—you could open a pull request on one of my repos, or Slack me in one of the bajillion conference or collaboration workspaces I'm in, or send a constellation of satellites in front of the Mayall Telescope on Kitt Peak spelling out your message so I'll find it in the DESI data—but probably just send me an email.

kstoreyf@stanford.edu
@kstoreyf