Stefania Salvadori

The Pop III IMF remains a mystery. The predicted massive nature of PopIII stars implies the existence of stars exploding as pair-instability supernovae (PISN) and now the LAMOST survey claims to have discovered a pure PISN descendant. We investigate the implications of this new discovery for the Pop III IMF, by statistical comparison with the predictions of our cosmological galaxy formation model, NEFERTITI. Continue reading True PISN descendant and Pop III IMF→

Our paper “The energy distribution of the first supernovae” presenting a state-of-the-art model to limit the first stars’ properties with stellar archaeology has been accepted for publication by MNRAS. Congratulations Ioanna! Continue reading NEFERTITI model: first stars & supernovae→

Our paper on Quiescent Low-Mass Galaxies Observed by JWST was highlighted as one of the most interesting recent results published in AAS journals. Congrats Vio!!!! Continue reading Our Gelli et al. paper highlighted by AAS!→

Our senior NEFERTITI’s member, Ása Skúladóttir, has been awarded an ERC Starting Grant by the European Research Council for the project TREASURE: Digging into Dwarf Galaxies. Congratulations Ása, you deserved it!! Continue reading ERC starting for our Ása Skúladóttir!→

For the first time, we were able to identify the chemical traces of the explosions of the first stars in very distant gas clouds. This is the key result of our ApJ paper which has been featured for an ESO press release. Continue reading Distant gas clouds with leftovers of the first stars!→

The surprising JWST discovery of a quiescent low-mass galaxy at redshift z = 7.3 represent a unique opportunity to study the imprint of feedback processes on early galaxy evolution. To interpret this finding we use the SERRA suite of cosmological zoom-in simulations and built a sample of 130 low-mass galaxies, 30% of which are quiescent.
Gelli, Salvadori et al. ApJ submitted Continue reading Interpreting the first quiescent dwarf galaxy→

Can we indirectly prove the existence of Pair Instability SuperNovae (PISN)? We demonstrate that the mean [C/Fe] of first stars polluted environments decreases with the increasing contribution of PISNe, and thus with the characteristic mass of the first stars. We conclude that the dearth of C-enhanced metal-poor stars in the Galactic bulge indirectly probes the existence of elusive PISNe, and propose a novel method which exploits this lack to constrain the mass distribution of the first stars.

Pagnini, Salvadori et al. 2023 MNRAS Continue reading PISN signature in the MW Bulge?→

We show that CEMP stars with A(C) > 6 are mainly enriched by AGB Pop II stars. We identify a new class of “moderate CEMP-s stars” with A(C) ~7 and 0 < [Ba/Fe] < + 1, imprinted by winds from AGB stars. Pop III descendants have A(C) < 6 and a constant [C/Mg] with [Fe/H], in perfect agreement with observations in Böotes I and the MW halo. Rossi, Salvadori+2023, MNRAS Letter Continue reading What are C-enhanced metal-poor stars?→

We present our PISN-explorer: an innovative tool to identify in large spectroscopic surveys the elusive descendants of very massive first stars exploding as Pair Instability SuperNovae!
Aguado, Salvadori, Skuladottir et al. 2023 Continue reading Our PISN-explorer paper is out!→

In his new paper as first author, our NEFERTITI’s member David Aguado, showed that the star SMSS1605-1443 is a truly second-generation object dwelling in a binary system. The gas out of which SMSS1605-1443 formed was directly polluted by low-energy primordial supernovae. Continue reading A 2nd-generation star in a binary system→