Signatures of very massive stars: supercollapsars and their cosmological rate

Abstract

We compute the rate of supercollapsars by using cosmological, N-body, hydro, chemistry simulations of structure formation, following detailed stellar evolution according to proper yields (for He, C, N, O, Si, S, Fe, Mg, Ca, Ne, etc.) and lifetimes for stars having different masses and metallicities, and for different stellar populations (population III and population II-I). We find that supercollapsars are usually associated to dense, collapsing gas with little metal pollution and with abundances dominated by oxygen. The resulting supercollapsar rate is about $10^{-2}\mathrm{y}{\mathrm{r}}^{-1}\mathrm{s}{\mathrm{r}}^{-1}$ at redshift $z=0$, and their contribution to the total rate is $<0.1$ per cent, which explains why they have never been detected so far. Expected rates at redshift $z\simeq 6$ are of the order of $\sim 10^{-3}\mathrm{y}{\mathrm{r}}^{-1}\mathrm{s}{\mathrm{r}}^{-1}$ and decrease further at higher $z$. Because of the strong metal enrichment by massive, short-lived stars, only $\sim 1$ supercollapsar generation is possible in the same star forming region. Given their sensitivity to the high-mass end of the primordial stellar mass function, they are suitable candidates to probe pristine population III star formation and stellar evolution at low metallicities.

6 pages; accepted, MNRAS. "Apri la mente a quel ch'io ti paleso" (Par. V, 40)

References in corpus (13)

• Chemical enrichment of galaxy clusters from hydrodynamical simulations
• Fragmentation of star-forming clouds enriched with the first dust
• Metal and molecule cooling in simulations of structure formation
• Metal and molecule cooling in simulations of structure formation
• Properties of Gamma-Ray Burst Progenitor Stars
• Stellar explosions powered by the Blandford-Znajek mechanism
• Formation of Massive Primordial Stars in a Reionized Gas
• Early structure formation in quintessence models and its implications for cosmic reionisation from first stars
• The host galaxies of long-duration GRBs in a cosmological hierarchical scenario
• Dark Matter Halo Environment for Primordial Star Formation
• Statistical properties of mass, star formation, chemical content and rotational patterns in early z > 9 structures
• The Potential for Detecting Gamma-Ray Burst Afterglows from Population III Stars with the Next Generation of Infrared Telescopes
• Hydrodynamical chemistry simulations of the SZ effect and the impacts from primordial non-Gaussianities

Cited by in corpus (6)

• Constraining the PopIII IMF with high-z GRBs
• The First Billion Years of a Warm Dark Matter Universe
• PopIII signatures in the spectra of PopII/I GRBs
• Can very massive Population III stars produce a super-collapsar?
• Metal enrichment signatures of the first stars on high-z DLAs
• Exploration of the high-redshift universe enabled by THESEUS