James Webb Space Telescope Feed Post

Harvard ADS: The JADES Transient Survey: Discovery and Classification of Supernovae in the JADES Deep Field

Paper abstract: The JWST Advanced Deep Extragalactic Survey (JADES) is a multi-cycle JWST program that has taken among the deepest near-infrared images to date (down to ~30.5 ABmag) over ~25 arcmin^2 in the GOODS-S field in two sets of observations with one year of separation. This presented the first opportunity to systematically search for transients, mostly supernovae (SNe), out to z>2. We found 79 SNe: 38 at z<2, 23 at 2 < z < 3, 8 at 3 < z < 4, 7 at 4 < z < 5, and 3 with undetermined redshifts, where the redshifts are predominantly based on spectroscopic or highly reliable JADES photometric redshifts of the host galaxies. At this depth, the detection rate is ~1-2 per arcmin^2 per year, demonstrating the power of JWST as a supernova discovery machine. We also conducted multi-band follow-up NIRCam observations of a subset of the SNe to better constrain their light curves and classify their types. Here, we present the survey, sample, search parameters, spectral energy distributions (SEDs), light curves, and classifications. Even at z>=2, the NIRCam data quality is such that we can perform multi-epoch light-curve fitting to classify supernovae with a reasonable degree of confidence. The multi-epoch SN sample includes a Type Ia SN at z_{spec}= 2.91, Type IIP SN at z_{spec}= 3.61, and a Type Ic-BL SN at z_{spec}= 2.845. We also found that two z~16 galaxy candidates from the first imaging epoch were actually transients that faded in the second epoch, illustrating the possibility that moderate/high-redshift SNe could mimic high-redshift dropout galaxies.