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Creators/Authors contains: "Das, Kaustav Kashyap"

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  1. Free, publicly-accessible full text available November 7, 2025
  2. Abstract One of the open questions following the discovery of GW170817 is whether neutron star (NS) mergers are the only astrophysical sites capable of producingr-process elements. Simulations have shown that 0.01–0.1Mofr-process material could be generated in the outflows originating from the accretion disk surrounding the rapidly rotating black hole that forms as a remnant to both NS mergers and collapsing massive stars associated with long-duration gamma-ray bursts (collapsars). The hallmark signature ofr-process nucleosynthesis in the binary NS merger GW170817 was its long-lasting near-infrared (NIR) emission, thus motivating a systematic photometric study of the light curves of broad-lined stripped-envelope (Ic-BL) supernovae (SNe) associated with collapsars. We present the first systematic study of 25 SNe Ic-BL—including 18 observed with the Zwicky Transient Facility and 7 from the literature—in the optical/NIR bands to determine what quantity ofr-process material, if any, is synthesized in these explosions. Using semi-analytic models designed to account forr-process production in SNe Ic-BL, we perform light curve fitting to derive constraints on ther-process mass for these SNe. We also perform independent light curve fits to models without ther-process. We find that ther-process-free models are a better fit to the light curves of the objects in our sample. Thus, we find no compelling evidence ofr-process enrichment in any of our objects. Further high-cadence infrared photometric studies and nebular spectroscopic analysis would be sensitive to smaller quantities ofr-process ejecta mass or indicate whether all collapsars are completely devoid ofr-process nucleosynthesis. 
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