Fast Lensing And Sub-minute High-accuracy photometry (FLASH) with JWST: Pipeline and Primordial Black Hole Microlensing Constraints from M31
Abstract
Minute- and sub-minute microlensing provides a direct probe of compact dark matter at asteroid-mass scales, where primordial black holes with MPBH <~ 10^-10 Msol would produce short-duration, finite-source-suppressed amplifications of stars in extragalactic fields. To enable these measurements, we present FLASH: Fast Lensing And Sub-minute High-accuracy photometry with JWST, a pipeline designed to recover such events from JWST/NIRCam imaging by preserving detector-ramp time information and performing high-precision crowded-field photometry. FLASH begins from Level 1 NIRCam data products, applies microlensing-oriented detector calibration (including improved treatment of non-linearity and position-dependent detector calibration), and extracts forced multi-band light curves in crowded fields. We apply the pipeline to two public JWST/NIRCam datasets targeting the disk of M31 with 21.5 s cadence: GO-4735 and GO-2609. Although these observations are suboptimal as a microlensing survey, they provide a stringent test of JWST time-domain performance in a high-surface-brightness, crowded stellar field. Using these data with our own microlensing simulations, we derive the first JWST-based microlensing constraints toward M31, finding fPBH <~ 100 for MPBH~ 10^-9 Msol. Our results demonstrate that JWST is a competitive platform for high-cadence microlensing and that a dedicated, continuous NIRCam monitoring program could substantially improve constraints on compact dark matter below the current ground-based frontier.
Related
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BibTeX
@misc{rubin2026fast,
title = {{Fast Lensing And Sub-minute High-accuracy photometry (FLASH) with JWST: Pipeline and Primordial Black Hole Microlensing Constraints from M31}},
author = {David Rubin and Istvan Szapudi},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.05610},
eprint = {2609.05610},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.05610},
}
RIS
TY - UNPB
TI - Fast Lensing And Sub-minute High-accuracy photometry (FLASH) with JWST: Pipeline and Primordial Black Hole Microlensing Constraints from M31
AU - David Rubin
AU - Istvan Szapudi
PY - 2026
DA - 2026/09/04
PB - arXiv
DO - 10.48550/arxiv.2609.05610
UR - https://arxiv.org/abs/2609.05610
AB - Minute- and sub-minute microlensing provides a direct probe of compact dark matter at asteroid-mass scales, where primordial black holes with MPBH <~ 10^-10 Msol would produce short-duration, finite-source-suppressed amplifications of stars in extragalactic fields. To enable these measurements, we present FLASH: Fast Lensing And Sub-minute High-accuracy photometry with JWST, a pipeline designed to recover such events from JWST/NIRCam imaging by preserving detector-ramp time information and performing high-precision crowded-field photometry. FLASH begins from Level 1 NIRCam data products, applies microlensing-oriented detector calibration (including improved treatment of non-linearity and position-dependent detector calibration), and extracts forced multi-band light curves in crowded fields. We apply the pipeline to two public JWST/NIRCam datasets targeting the disk of M31 with 21.5 s cadence: GO-4735 and GO-2609. Although these observations are suboptimal as a microlensing survey, they provide a stringent test of JWST time-domain performance in a high-surface-brightness, crowded stellar field. Using these data with our own microlensing simulations, we derive the first JWST-based microlensing constraints toward M31, finding fPBH <~ 100 for MPBH~ 10^-9 Msol. Our results demonstrate that JWST is a competitive platform for high-cadence microlensing and that a dedicated, continuous NIRCam monitoring program could substantially improve constraints on compact dark matter below the current ground-based frontier.
ER -