Results from numerical simulations of primordial structure formation will be presented and their implications for early pristine population III stars and the transition to the following metal-enriched popII/I regimes will be discussed. A number of observables will be used to test different population III stellar models (in terms of mass and metal yields) and to rule out non performing ones, as...
Constraining the properties of the first generation of stars is one of the key motivations of the James Webb Space Telescope. I will discuss strategies for identifying genuine Pop III stellar populations, potential contaminants, and learnings from nearly one full year of JWST data.
In recent years observations of blank fields enabled us to detect galaxies as far as z~11. However, very little is known about those galaxies, and they are mostly the most luminous representatives. Observations with James Webb Space Telescope will revolutionize this field. In particular, grism spectrograph NIRISS provides observing modes for slitless spectroscopy, which will be unique in...
Individual stars are typically not detectable beyond the local Universe, but gravitational lensing by foreground galaxy clusters can in rare cases raise the brightness of extremely distant stars to detectable levels. More than a dozen lensed stars at z~1-3 have already been detected this way using HST and JWST, along with a smaller number of candidates at z~5-6 (including the current record...
An efficient search for elusive PopIII sources/ stellar complexes at high redshift is a trade-off between different aspects related to (1) the available instrumentation (technical) and (2) the physical conditions which maximize their occurrence (physics). The necessity of reaching quite faint luminosity while keeping an elevated spatial contrast (both spectroscopy and photometry) seems the...
