The Connection between Gamma-Ray Bursts and Extremely Metal-Poor Stars: Black Hole-forming Supernovae with Relativistic Jets

Long-duration gamma-ray bursts (GRBs) are thought to be connected to luminous and energetic supernovae (SNe), called hypernovae (HNe), resulting from the black-hole (BH) forming collapse of massive stars. For recent nearby GRBs~060505 and 060614, however, the expected SNe have not been detected. The upper limits to the SN brightness are about 100 times fainter than GRB-associated HNe (GRB-HNe), corresponding to the upper limits to the ejected ${}^{56}$Ni masses of $M({}^{56}\mathrm{N}\mathrm{i})\sim {10}^{-3}{M}_{\odot }$. SNe with a small amount of ${}^{56}$Ni ejection are observed as faint Type II SNe. HNe and faint SNe are thought to be responsible for the formation of extremely metal-poor (EMP) stars. In this Letter, a relativistic jet-induced BH forming explosion of the 40 $M_{\odot }$ star is investigated and hydrodynamic and nucleosynthetic models are presented. These models can explain both GRB-HNe and GRBs without bright SNe in a unified manner. Their connection to EMP stars is also discussed. We suggest that GRBs without bright SNe are likely to synthesize $\text{Mni}\sim {10}^{-4}$ to ${10}^{-3}{M}_{\odot }$ or $\sim {10}^{-6}{M}_{\odot }$.