James Webb Space Telescope Feed Post

The first fireworks: A roadmap to Population III stars during the Epoch of Reionization through Pair Instability Supernovae

Paper abstract: With the launch of JWST and other scheduled missions aimed at probing the distant Universe, we are entering a new promising era for high-z astronomy. One of our main goals is the detection of the first population of stars (Population III or Pop III stars), and models suggest that Pop III star formation is allowed well into the Epoch of Reionization (EoR), rendering this an attainable achievement. In this paper, we focus on our chance of detecting massive Pop IIIs at the moment of their death as Pair-Instability Supernovae (PISNe). We estimate the probability of discovering PISNe during the EoR in galaxies with different stellar masses (7.5 <= \mathrm{Log}(M_*/\mathrm{M_\odot}) <= 10.5) from six dustyGadget simulations of 50h^{-1} cMpc per side. We further assess the expected number of PISNe in surveys with JWST/NIRCam and Roman/WFI. On average, less than one PISN is expected in all examined JWST fields, while ~eq 1.5 \, \eta_\mathrm{III} PISNe may be found in a ~ 1 deg^2 Roman field, with potential for increased discoveries when considering more optimistic choices for the Pop III initial mass function and formation efficiency \eta_\mathrm{III}, and when including the contribution of coarsely-resolved environments. JWST/NIRCam and Roman/WFI allow the detection of massive-progenitor (~ 250 \mathrm{M_\odot}) PISNe throughout all the optimal F200W-F356W, F277W-F444W, and F158-F213 colors. PISNe are also predominantly located at the outskirts of their hosting haloes, facilitating the disentangling of underlying stellar emission thanks to the spatial-resolution capabilities of the instruments.