Survey strategies for the first supernovae with JWST

摘要

Pair-instability supernovae (PISNe) are very luminous explosions of massive,low metallicity stars. They can potentially be observed out to high redshiftsdue to their high explosion energies, thus providing a probe of the Universeprior to reionisation. The near-infrared camera, NIRCam, on board the JamesWebb Space Telescope is ideally suited for detecting their redshiftedultraviolet emission. We calculate the photometric signature of high-redshiftPISNe and derive the optimal survey strategy for identifying their promptemission and possible afterglow. We differentiate between PISNe and othersources that could have a similar photometric signature, such as activegalactic nuclei or high redshift galaxies. We demonstrate that the optimalsurvey strategy, which maximises the visibility time of the PISN lightcurve perinvested exposure time, consists of the two wide-band filters F200W and F356Wwith an exposure time of 600s. The PISN afterglow, caused by nebular emissionand reverberation, is very faint and requires unfeasibly long exposure times tobe uniquely identified. However, this afterglow would be visible for severalhundred years, about two orders of magnitude longer than the prompt emission,rendering PISNe promising targets for future, even more powerful telescopes.