What can ELT add to what we are learning about galaxy evolution with JWST? Answering that question is one of our goals this week in Ringberg Castle during a workshop organized by @maxplanck.de

We find several candidates with very blue spectral energy distributions. Those would point to very young stars, maybe Pop III and/or with many very massive stars, and/or also with low escape fractions of ionizing photons.

What must be happening in those dark matter halos at z>12? We don’t know in detail, but we tried to constrain the number of UV photons that halos of different mass es should produce (with stars or with super-massive black holes).

We compare with some of the latest galaxy formation simulations, and we find that the efficiency of star formation at z>12 should increase, at least up to z~17. At z~25, no model predicts that we should be finding any galaxy. If those guys are confirmed, how they got there?!

We are witnessing the rise of the galactic empire, when galaxies started their journey in the Universe. From z~12, where we already have several confirmed galaxies , to z~17, the cosmic UV luminosity density decreases by a factor of 4, and by a factor of 25 up to z~25.

We estimate luminosity functions at z~17 and z~25. We are consistent with all previously estimated upper limits, and a bit below the numbers obtained by recent works at z~17. At z~25, we are the first ones to find candidates.

This work has only been possible thanks to all the folks in MIDIS and NGDEEP. Adding both datasets we have 40-80 hours exposure time per band, reaching magnitude 31.5 in all the relevant filters! (F200W through F444W).