Meredith L. Rawls, PhD

Developing software for a firehose of telescope data and using binary stars to study the cosmos

I work with the Rubin Observatory Legacy Survey of Space and Time (LSST) Data Management group at the University of Washington. I am a Research Scientist in the Department of Astronomy and a DIRAC Fellow. The LSST will collect frames for a decade-long movie of the sky beginning in 2022. My team develops software to process terabytes of nightly data. I'm also an active researcher in stellar astrophysics and a relentless science communicator.

My CV in PDF form is available here.

Software by and for astronomers

Astronomy has come a long way since sketching the view through a handheld telescope, and modern-day astronomers use a wide array of software to study digital images of the sky.

panoramic rendering of the finished LSST at Cerro Pachon in Chile

Things that go bump in the night

LSST's Data Management team at the University of Washington focuses on Alert Production. We are writing algorithms to process huge images from the LSST camera in real time, identify objects in the night sky that have changed, and issue an appropriate alert so these interesting targets can be followed up.
Learn more about our work here.

cartoon of difference imaging showing new image, template image, and difference image

Difference imaging precursor datasets

LSST will subtract a reference template image from a new image fresh off the telescope, and anything that changes or moves may be interesting. I work to measure and reduce false positives in difference images for precursor datasets, and I develop visualization tools for large-scale difference imaging.

astronomers collaborating on programming around circular tables in a conference room

Building tools for the community

The software being designed for LSST images is open source and works with popular python packages like astropy. Astronomers worldwide can use our tools to analyze data from their favorite telescope too.
Check out the LSST Science Pipelines here.

Stars are not always predictable

But when stars come in pairs (or more!), or pulse or flicker in unusual ways, we can reveal stellar secrets by observing how they vary in brightness.

illustration of comet and dust debris blocking thie light from a star

Searching for mysterious dippers

I am collaborating with researchers in UW's DIRAC Institute to search new data from the Zwicky Transient Facility for strange variable stars similar to Boyajian's Star. I co-wrote an Astrobite about this mysterious sytem when it was first discovered.

multi-color image of the DECam field of view with a difference imaging cartoon overlaid

Comparing difference imaging pipelines

I am working with UW undergrad Thomas Waters to compare variable sources classified in the High Cadence Transient Survey (HiTS) data release with the same data processed with LSST software. HiTS is an LSST precursor we can use to improve LSST software before the 10-year survey begins. Thomas is particularly interested in analyzing difference imaging light curves of variable Active Galactic Nuclei. Courtney Hooks also worked on this project with us in Fall 2019 with the Pre-MAP 15 Cohort.

illustration of the portion of the sky APOGEE observed that includes the Kepler field

Pairing data from APOGEE and Kepler

I led a research collaboration to identify and model eclipsing binary systems observed by both the Kepler space telescope and the APOGEE spectrograph. The main result was a paper by Joni Marie Clark Cunningham for whom this project comprised the majority of her Master's Thesis. We measured precise masses and radii for seven binary pairs and modeled their evolutionary histories. The collaboration had team members from Fisk-Vanderbilt, New Mexico State University, and UW.

cartoon of a red giant binary with oscillations being eclipsed by a main sequence star

Eclipsing binaries and asteroseismology

Because there are many more oscillating stars than eclipsing binaries, my PhD thesis modeled binaries as a benchmark for measuring stellar properties with asteroseismology. My team and I revealed that some evolved red giants in binary systems don't oscillate at all. Read about one particularly interesting binary.

Beyond research and programming

I am involved in a variety of important projects in addition to my work with LSST and stellar astronomy.

Publications

  • APOGEE/Kepler Overlap Yields Orbital Solutions for a Variety of Eclipsing Binaries
    J. M. C. Cunningham, M. L. Rawls, D. Windemuth, A. Ali, et al. 2019, AJ, 158, 106
  • An Overview of the LSST Image Processing Pipelines
    J. Bosch, [24 alphabetized co-authors], M. L. Rawls, [8 alphabetized co-authors]. 2018, ADASS XXVIII
  • DMTN-039: A Prototype Alert Production Pipeline
    M. L. Rawls 2017, LSST Data Management Technical Note, dmtn-039.lsst.io
  • Testing the Asteroseismic Scaling Relations for Red Giants with Eclipsing Binaries Observed by Kepler
    P. Gaulme, J. McKeever, J. Jackiewicz, M. L. Rawls, et al. 2016, ApJ, 832, 121
  • Red Giants in Eclipsing Binaries as a Benchmark for Asteroseismology
    M. L. Rawls 2016, PhD Thesis
    Committee: J. Jackiewicz (chair), L. Boucheron, P. Gaulme, T. Harrison, & R. Walterbos
  • KIC 9246715: The Double Red Giant Eclipsing Binary With Odd Oscillations
    M. L. Rawls, P. Gaulme, J. McKeever, J. Jackiewicz, et al. 2016, ApJ, 818, 108
  • Red Giants in Eclipsing Binary and Multiple-Star Systems: Modeling and Asteroseismic Analysis of 70 Candidates from Kepler Data
    P. Gaulme, J. McKeever, M. L. Rawls, J. Jackiewicz, et al. 2013, ApJ, 767, 82
  • Refined Neutron Star Mass Determinations for Six Eclipsing X-Ray Pulsar Binaries
    M. L. Rawls, J. A. Orosz, J. E. McClintock, M. A. P. Torres, et al. 2011, ApJ, 730, 25
View my publications on ADS

CV