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Arxiv: JWST Photometric Time-Delay and Magnification Measurements for the Triply-Imaged Type Ia "Supernova H0pe" at z = 1.78 Published: 3/27/2024 8:57:15 PM Updated: 7/23/2024 12:18:33 AM

Paper abstract: Supernova (SN) H0pe is a gravitationally lensed, triply-imaged, Type Ia SN(SN Ia) discovered in James Webb Space Telescope imaging of the PLCKG165.7+67.0 cluster of galaxies. Well-observed multiply-imaged SNe provide arare opportunity to constrain the Hubble constant (H_0), by measuring therelative time delay between the images and modeling the foreground massdistribution. SN H0pe is located at z=1.783, and is the first SN Ia withsufficient light curve sampling and long enough time delays for an H_0inference. Here we present photometric time-delay measurements and SNproperties of SN H0pe. Using JWST/NIRCam photometry we measure time delays of\Delta t_{ab}=-116.6^{+10.8}_{-9.3} and \Delta t_{cb}=-48.6^{+3.6}_{-4.0}observer-frame days relative to the last image to arrive (image 2b; alluncertainties are 1\sigma), which corresponds to a ~5.6\% uncertaintycontribution for H_0 assuming 70 \rm{km s^{-1} Mpc^{-1}}. We also constrainthe absolute magnification of each image to \mu_{a}=4.3^{+1.6}_{-1.8},\mu_{b}=7.6^{+3.6}_{-2.6}, \mu_{c}=6.4^{+1.6}_{-1.5} by comparing theobserved peak near-IR magnitude of SN H0pe to the non-lensed population of SNeIa.