Type Ic core-collapse supernova explosions evolved from very massive stars

Abstract

We investigate the possibility of a super-luminous Type Ic core-collapse supernovae producing a large amount of 56 Ni. Very massive stars with a main-sequence mass larger than 100 M ⊙ and a metallicity 0.001 < Z 0.004 are expected to explode as super-luminous Type Ic supernovae. Stars with ∼ 110 − 150 M ⊙ and Z 0.001 would explode as Type Ic pulsational pair-instability supernovae if the whole H and He layers has been lost by the mass loss during pulsational pair-instability. We evaluate the total ejecta mass and the yields of 56 Ni, O, and Si in core-collapse supernovae evolved from very massive stars. We adopt 43.1 and 61.1 M ⊙ WO stars with Z = 0.004 as supernova progenitors expected to explode as Type Ic core-collapse supernovae. These progenitors have masses of 110 and 250 M ⊙ at the zero-age main sequence. Spherical explosions with an explosion energy larger than 2 × 10 52 erg produce more than 3.5 M ⊙ 56 Ni, enough to reproduce the light curve of SN 2007bi. Asphericity of the explosion affects the total ejecta mass as well as the yields of 56 Ni, O, and Si. Aspherical explosions of the 110 and 250 M ⊙ models reproduce the 56 Ni yield of SN 2007bi. These explosions will also show large velocity dispersion. An aspherical core-collapse supernova evolved from a very massive star is a possibility of the explosion of SN 2007bi.

Neutrino-driven explosions of ultra-stripped Type Ic supernovae generating binary neutron stars

“…To make initial conditions for hydrodynamics simulations, we first perform stellar evolutionary simulations of CO cores with masses of 1.45, 1.5, 1.6, 1.8, and 2.0 M⊙ supposing that stellar mass loss has already occurred by their hypothetical companion NSs. By removing stellar envelope, the stellar evolutionary simulations are done with a code described in Umeda et al (2012); Takahashi et al (2013); Yoshida et al (2014). The nuclear reaction network consists of 300 species of nuclei (Takahashi et al 2013;Yoshida et al 2014).…”

“…By removing stellar envelope, the stellar evolutionary simulations are done with a code described in Umeda et al (2012); Takahashi et al (2013); Yoshida et al (2014). The nuclear reaction network consists of 300 species of nuclei (Takahashi et al 2013;Yoshida et al 2014). Schwarzschild criterion is employed as the convection criterion and the convective mixing of the chemical composition is evolved using diffusion equation.…”

Mass ejection by pulsational pair instability in very massive stars and implications for luminous supernovae

“…In metal-poor stars, the mass range strongly depends on mass-loss rate. A part of very massive stars with the metallicity Z 0.004 experience the PPI (Yoshida & Umeda 2011;Yoshida, Okita & Umeda 2014). Recently, evolution of metal-poor very mas-⋆ E-mail: tyoshida@astron.s.u-tokyo.ac.jp sive stars has been investigated (e.g.…”

“…Recently, evolution of metal-poor very mas-⋆ E-mail: tyoshida@astron.s.u-tokyo.ac.jp sive stars has been investigated (e.g. Langer et al 2007;Yungelson, et al 2008;Yoshida & Umeda 2011;Yusof, et al 2013;Yoshida, Okita & Umeda 2014) for superluminous supernovae (SLSNe) (Smith et al 2007;Gal-Yam et al 2009) and new findings of very massive stars (Crowther et al 2010).…”

“…Several possibilities of emission processes such as the interaction between circumstellar medium (CSM) released by eruptive massloss and the SN ejecta, mass ejection from nascent magnetars (e.g. Maeda et al 2007;Kasen & Bildsten 2010), PISNe (Gal-Yam et al 2009), and core-collapse (CC) SNe after PPI (Moriya et al 2010;Yoshida, Okita & Umeda 2014) have been proposed. Another class of candidates of PPI events are bright optical transients which were found in a few years before SN explosion for some SNe such as SN 2006jc (Pastorello et al 2007) and SN 2009ip (Pastorello et al 2013).…”