Exploring the Fate of Stellar Core Collapse with Supernova Relic Neutrinos

Abstract

Core collapse of massive stars leads to different fates for various physical factors, which gives different spectra of the emitted neutrinos. We focus on the supernova relic neutrinos (SRNs) as a probe to investigate the stellar collapse fate. We present the SRN fluxes and event rate spectra at a detector for three resultant states after stellar core collapse, the typical mass neutron star, the higher mass neutron star, or the failed supernova forming a black hole, based on different nuclear equations of state. Then possible SRN fluxes are formed as mixtures of the three components. We also show the expected sensitivities at the next-generation water-based Cherenkov detectors, SK-Gd and Hyper-Kamiokande, as constraining the mixture fractions. This study provides a practical example of extracting astrophysical constraints through SRN measurement.

Non-universal stellar initial mass functions: large uncertainties in star formation rates at z ≈ 2–4 and other astrophysical probes

“…The former can be calculated as described in Section 3.3 , while a calculation of the latter is sketched here. Following Møller et al ( 2018 ) and Ashida & Nakazato ( 2022 ), we consider three possible outcomes of supernovae, depending on the mass of their stellar progenitor. Stars can either evolve into black holes or low/high-mass neutron stars.…”

Diffuse Neutrino Flux Based on the Rates of Core-collapse Supernovae and Black Hole Formation Deduced from a Novel Galactic Chemical Evolution Model

“…According to Woosley et al (2020), the NS mass distribution has a central peak near 1.35M e and the fraction of high-mass NSs at birth is far lower. 6 Thus, in the present study, we adopt the neutrino spectrum of the canonicalmass NS model with ∼1.35M e in Ashida & Nakazato (2022),…”

“…In the BH formation case, the neutrino spectrum is harder than that of the case with an NS. More details of the reference model for the neutrino spectrum in this study are described in Ashida & Nakazato (2022). We then describe the DSNB flux as…”

“…In particular, neutrinos from the core collapse of massive stars over cosmic history have accumulated to form the diffuse supernova neutrino background (DSNB), or they are referred to as supernova relic neutrinos, and they are expected to provide knowledge of not only collapsing stars, but also cosmic chemical evolution, etc. Impacts of physical and astrophysical factors on the DSNB have been studied actively in many theoretical works (e.g., Totani & Sato 1995;Totani et al 1996;Hartmann & Woosley 1997;Malaney 1997;Kaplinghat et al 2000;Ando et al 2003;Horiuchi et al 2009Horiuchi et al , 2018Horiuchi et al , 2021Lunardini 2009;Galais et al 2010;Nakazato 2013;Nakazato et al 2015;Mathews et al 2020;Kresse et al 2021;Tabrizi & Horiuchi 2021;Ashida & Nakazato 2022;Ekanger et al 2022;Ziegler et al 2022;Anandagoda et al 2023;Aoyama et al 2023). In the experimental field, an observation of the DSNB flux has yet to be accomplished; however, a recent search at the Super-Kamiokande (SK) water Cherenkov detector has excluded some optimistic models and placed upper bounds on the DSNB e n ¯flux close to many theoretical predictions, within a factor of 10 (Abe et al 2021).…”

Search for Astrophysical Electron Antineutrinos in Super-Kamiokande with 0.01% Gadolinium-loaded Water

“…The theoretical expectations for the DSNB flux depend on various parameters: the supernova rate introduced from the cosmic star formation rate depending on the redshift, the neutrino mass ordering, the equations of states for remnant neutron stars, the metallicity of the galaxy, the failed supernova rate, and the binary interaction effect of stars (Hartmann & Woosley 1997;Malaney 1997;Kaplinghat et al 2000;Ando et al 2003;Ando 2005;Horiuchi et al 2009;Lunardini 2009;Galais et al 2010;Nakazato et al 2015;Horiuchi et al 2018Horiuchi et al , 2021Kresse et al 2021;Tabrizi & Horiuchi 2021;Ekanger et al 2022). Ashida & Nakazato (2022) have investigated the fraction for the failed CCSNe forming black holes from the DSNB flux upper limit.…”