Diffuse supernova neutrino background from extensive core-collapse simulations of 8–100 M⊙ progenitors

Abstract

We revisit the diffuse supernova neutrino background in light of recent systematic studies of stellar core collapse that reveal the quantitative impacts of the progenitor conditions on the collapse process. In general, the dependence of the core-collapse neutrino emission on the progenitor is not monotonic in progenitor initial mass, but we show that it can, at first order, be characterized by the core compactness. For the first time, we incorporate the detailed variations in the neutrino emission over the entire mass range 8-100M , based on (i) a long-term simulation of the core collapse of a 8.8M ONeMg core progenitor, (ii) over 100 simulations of iron core collapse to neutron stars, and (iii) half a dozen simulations of core collapse to black holes (the "failed channel"). The fraction of massive stars that undergo the failed channel remains uncertain, but in view of recent simulations which reveal high compactness to be conducive to collapse to black holes, we characterize the failed fraction by considering a threshold compactness above which massive stars collapse to black holes and below which the final remnant is a neutron star. We predict that future detections of the diffuse supernova neutrino background may have the power to reveal this threshold compactness, if its value is relatively small as suggested by interpretations of several recent astronomical observations.

Diffuse Supernova Neutrino Background Search at Super-Kamiokande

“…shown only for the signal window. Right: upper limits on the extraterrestrial electron antineutrino flux from the present work, in comparison with previous published results from SK [1,2] and KamLAND [7] and theoretical predictions from Refs [2,[8][9][10][11][12][13] (in gray).…”

Fast neutrino flavor conversion modes in multidimensional core-collapse supernova models: The role of the asymmetric neutrino distributions

“…A few representative φ ν -integrated angular distributions of ν e ,ν e and the corresponding ELN (Eqs. (10) and (11)) are presented in (expectedly) to capture the angular structures at small emission angles. In fact, as the radius gets larger, the ELN crossings get narrower because the neutrino angular distributions become more forward peaked.…”

Non-exploding and exploding core-collapse supernova models and the multimessenger predictions

“…The detection of the short-live (∼ 300 ms after bounce) neutrino signals are basically limited to Galactic events (see Mirizzi et al (2016) for a review). However, further study would be needed to clarify the contribution of these BH forming massive stars to the prediction of diffuse neutrino supernova background (e.g., Lunardini (2009); Horiuchi et al (2018)). Figure 4 shows the neutrino and GW signals (Takiwaki and Kotake (2018)) obtained in 3D core-collapse supernova simulation of a rapidly rotating 27 M star that is exploding due to the growth of the so-called low-T/|W | instability (Takiwaki et al (2016)).…”