%0 Generic %1 debennassuti2016limits %A de Bennassuti, M. %A Salvadori, S. %A Schneider, R. %A Valiante, R. %D 2016 %K Fe imf metal poor popIII stars %T Limits on Pop III star formation with the most iron-poor stars %U http://arxiv.org/abs/1610.05777 %X We study the impact of star-forming mini-haloes, and the Initial Mass Function (IMF) of Population III (Pop III) stars, on the Galactic halo Metallicity Distribution Function (MDF) and on the properties of C-enhanced and C-normal stars at Fe/H<-3. For our investigation we use a data-constrained merger tree model for the Milky Way formation, which has been improved to self-consistently describe the physical processes regulating star-formation in mini-haloes, including the poor sampling of the Pop III IMF. We find that only when star-forming mini-haloes are included the low-Fe tail of the MDF is correctly reproduced, showing a plateau that is built up by C-enhanced metal-poor (CEMP) stars imprinted by primordial faint supernovae. The incomplete sampling of the Pop III IMF in inefficiently star-forming mini-haloes (< $10^-3$ $M_ødot$/yr) strongly limits the formation of Pair Instability Supernovae (PISNe), with progenitor masses $m_\rm popIII$=140-260 $M_ødot$, even when a flat Pop III IMF is assumed. Second-generation stars formed in environments polluted at >50% level by PISNe are thus extremely rare, corresponding to $\approx$ 0.25% of the total stellar population at Fe/H<-2, which is consistent with recent observations. The low-Fe tail of the MDF strongly depends on the Pop III IMF shape and mass range. Given the current statistics, we find that a flat Pop III IMF model with $m_popIII$=10-300 $M_ødot$ is disfavoured by observations. We present testable predictions for Pop III stars extending down to lower masses, with $m_popIII$=0.1-300 $M_ødot$.

@misc{debennassuti2016limits, abstract = {We study the impact of star-forming mini-haloes, and the Initial Mass Function (IMF) of Population III (Pop III) stars, on the Galactic halo Metallicity Distribution Function (MDF) and on the properties of C-enhanced and C-normal stars at [Fe/H]<-3. For our investigation we use a data-constrained merger tree model for the Milky Way formation, which has been improved to self-consistently describe the physical processes regulating star-formation in mini-haloes, including the poor sampling of the Pop III IMF. We find that only when star-forming mini-haloes are included the low-Fe tail of the MDF is correctly reproduced, showing a plateau that is built up by C-enhanced metal-poor (CEMP) stars imprinted by primordial faint supernovae. The incomplete sampling of the Pop III IMF in inefficiently star-forming mini-haloes (< $10^{-3}$ $M_\odot$/yr) strongly limits the formation of Pair Instability Supernovae (PISNe), with progenitor masses $m_{\rm popIII}$=[140-260] $M_\odot$, even when a flat Pop III IMF is assumed. Second-generation stars formed in environments polluted at >50% level by PISNe are thus extremely rare, corresponding to $\approx$ 0.25% of the total stellar population at [Fe/H]<-2, which is consistent with recent observations. The low-Fe tail of the MDF strongly depends on the Pop III IMF shape and mass range. Given the current statistics, we find that a flat Pop III IMF model with $m_{\rm popIII}$=[10-300] $M_\odot$ is disfavoured by observations. We present testable predictions for Pop III stars extending down to lower masses, with $m_{\rm popIII}$=[0.1-300] $M_\odot$.}, added-at = {2016-10-20T09:57:13.000+0200}, author = {de Bennassuti, M. and Salvadori, S. and Schneider, R. and Valiante, R.}, biburl = {https://www.bibsonomy.org/bibtex/25af9b6e947f7daea5b69be5fad2bac69/miki}, description = {[1610.05777] Limits on Pop III star formation with the most iron-poor stars}, interhash = {69f05c0d225400df8056d7dba62f3580}, intrahash = {5af9b6e947f7daea5b69be5fad2bac69}, keywords = {Fe imf metal poor popIII stars}, note = {cite arxiv:1610.05777Comment: 15 pages, 11 figures. Accepted for publication in MNRAS}, timestamp = {2016-10-20T09:57:13.000+0200}, title = {Limits on Pop III star formation with the most iron-poor stars}, url = {http://arxiv.org/abs/1610.05777}, year = 2016 }