Papers › Initial Characterization of Stellar Photometry of Roman images from the OpenUniverse...

Initial Characterization of Stellar Photometry of Roman images from the OpenUniverse Simulations

4 Jun 2025arXiv:2506.04332links table onlyarchive 2025-07-28

Lauren Aldoroty, Daniel Scolnic, Arun Kannawadi, Rob Knop, Benjamin Rose, Rebekah Hounsell, Michael Troxel

The archive published only this paper's code-link row. Authors, date and abstract are from arXiv's metadata (CC0), read from the Kaggle arXiv metadata snapshot of 2026-09-12 where its title matched the archive's; the title is the archive's.

NASA's Nancy Grace Roman Space Telescope (Roman) will provide an opportunity to study dark energy with unprecedented precision and accuracy using several techniques, including measurements of high-z Type Ia Supernovae (SNe Ia, z ≲3.0) via the High-Latitude Time Domain Survey (HLTDS). In this work, we do an initial "benchmark" characterization of the photometric repeatability of stellar fluxes, which must be below 1% when sky noise is subdominant in order to enable a number of calibration requirements. Achieving this level of flux precision requires attention to Roman's highly-structured, spatially-varying, undersampled PSF. In this work, we build a library of effective PSFs (ePSFs) compatible with the OpenUniverse HLTDS simulations. Using our library of ePSFs, we recover stellar flux to between 0.6 - 1.2% photometric precision, finding that redder bands perform better by this metric. We also find that flux recovery is improved by up to 20% when a chip (sensor chip assembly; SCA) is divided into 8 sub-SCAs in order to account for the spatial variation of the PSF. With our optimized algorithm, we measure non-linearity due to photometry (magnitude dependence) of |s_(NL)| < 1.93 ×10⁻³ per dex, which is still larger than stated requirements for detector effects and indicates that further work is necessary. We also measure the dependence of photometric residuals on stellar color, and find the largest possible dependence in R062, implying a color-dependent PSF model may be needed. Finally, we characterize the detection efficiency function of each OpenUniverse Roman filter, which will inform future studies.

PaperPDFCode

Code

roman-supernova-pit/pub-aldoroty-2025a officialmentioned in paper report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

Not run by Syntology. Nothing on this page verifies that the listed code works.

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections