Primordial Stars in Cosmic Mirages

Sammanfattning

The very first generation of chemically pristine (Population III) stars remains elusive. However, the deep imaging provided by the James Webb Space Telescope (JWST) now probes further into cosmic history than ever before, opening new possibilities for their detection. This report explores the prospects of detecting Population III stars near the critical curves of gravitationally lensing galaxy clusters in ten JWST/NIRCam (Near Infra-Red Camera) filters. This is done by adopting state-of-the-art stellar evolutionary tracks, and exploring several initial mass function (IMF) prescriptions. The results show lower probabilities than earlier studies, with only the most top-heavy IMFs yielding observationally feasible prospects. The effects of microlensing on the magnification distribution and its implication for detectability are also discussed.