Type: Talk
Session: Transient and Variable Star Science II
Author: Brenda Frye

Abstract: The z=1.78 "SN H0pe" is one of the two most distant lensed Type Ia supernovae (SNe). SN H0pe is lensed by a foreground galaxy cluster into three different images which represent three different stages during its explosion. The delay in the SN image arrival times is presented by both photometric and (for the first time) also a spectroscopic approach. In parallel, seven independent lens models were constructed each using the same identical set of lensing constraints. The work of all these subgroups was strictly blinded from each other. After the live unblinding event, no changes were made thereafter to the image, spectral, or model analysis unless. The model-predicted time delays were computed given a fiducial value for H0, which were scaled to the photometric and spectroscopically-measured values to obtain the H0 inference. Our JWST/NIRSpec spectroscopy shows the host galaxy to be a massive (5.0 +/- 0.1) x 10^11 Msun) and somewhat dusty galaxy that sustains star formation at a rate of 30-60 Msun/yr, and to be surrounded by smaller, star-forming or starbursting satellites that make up a compact galaxy group. There is also a second compact galaxy group at z=2.24 within the strongly lensed region. The total (unobscured and obscured) star-formation rate of these two groups exceeds 200 Msun/yr) in the observed-frame, implying a SN rate ~0.7 SN/yr that is comparable to all six Hubble Frontier Fields combined. Therefore, additional monitoring of this field may be well-rewarded with new SN discoveries.