FLASH Talks: Brenda Frye (Steward) & TBA

Viernes, 12 Abril 2024 mediodía — 1 p.m. MST

NOIRLab Headquarters | 950 North Cherry Ave., Tucson, AZ 85719

Brenda Frye (Steward Observatory) & TBA ()

Brenda Frye, Steward Observatory

Measuring Hubble's Constant with James Webb Space Telescope JWST Observations of the Type Ia Supernova H0pe


A brief review of cluster lensing in the first 18 months of JWST PEARLS-Clusters observations is presented, ranging from the spectacle of the publicly-available "first light" images to the galaxy cluster fields that uncover unprecedented levels of lensing evidence in the form of giant arcs and image multiplicities. A point-source was discovered in the JWST image of one galaxy cluster field, PLCK G165.7+67.0 (G165), that is bright and appears in three different locations as a result of the strong lensing effects. Additional JWST observations confirm this source to be a normal Type Ia supernova (SN) at a redshift of 1.783 that we call "SN H0pe," making it the highest redshift lensed standard candle. In a strictly-observed "double-blind" approach, time delays between the images were measured, and seven independent lens models were constructed. During the unblinding event, the time delays were converted into a value for Hubble's constant by a scaled fit to the lens models. This is only the second measurement of Hubble's constant by the method of a multiply-imaged supernova, and the first by the JWST. With JWST, Rubin, and Roman observatories coming on-line soon, this approach has a promising future.