Neutrino and gravitational wave signal of a delayed-detonation model of type Ia supernovae

Abstract

The progenitor system(s) and the explosion mechanism(s) of Type Ia supernovae (SNe Ia) are still under debate. Non-electromagnetic observables, in particular gravitational waves and neutrino emission, of thermonuclear supernovae are a complementary window to light curves and spectra for studying these enigmatic objects. A leading model for SNe Ia is the thermonuclear incineration of a near-Chandrasekhar mass carbon-oxygen white dwarf star in a "delayed-detonation". We calculate a three-dimensional hydrodynamic explosion for the N100 delayed-detonation model extensively discussed in the literature, taking the dynamical effects of neutrino emission from all important contributing source terms into account. Although neutrinos carry away 2 × 10 49 erg of energy, we confirm the common view that neutrino energy losses are dynamically not very important, resulting in only a modest reduction of final kinetic energy by two per cent. We then calculate the gravitational wave signal from the time evolution of the quadrupole moment. Our model radiates 7 × 10 39 erg in gravitational waves and the spectrum has a pronounced peak around 0.4 Hz. Depending on viewing angle and polarization, we find that the future space-based gravitational wave missions DECIGO and BBO would be able to detect our source to a distance of ∼1.3 Mpc. We predict a clear signature of the deflagration-to-detonation transition in the neutrino and the gravitational wave signals. If observed, such a feature would be a strong indicator of the realization of delayed-detonations in near-Chandrasekhar mass white dwarfs.

Neutrinos from type Ia supernovae: The deflagration-to-detonation transition scenario

“…The red diamonds represent all ν and ν luminosity arising from process (5). The blue, black and red lines are those computed in [67]. The agreement between the values calculated via NuLib, and the values dynamically calculated in the N100ν model, is remarkable.…”

“…The agreement between the values calculated via NuLib, and the values dynamically calculated in the N100ν model, is remarkable. The agreement is less good for ν e , which is a reflection of the fact that [67] included β ± decays in the NSE material by implementing the tables of [79]. The small differences are not worrisome because ν e emission is dominated by pair production, which has much better agreement.…”

“…The simulation we adopt is the DDT SN Ia by Seitenzahl et al [67]. We restrict our attention to this one particular model in order to explain the many details of the calculation and leave alternative explosion mechanisms for future investigation.…”

Do electron-capture supernovae make neutron stars?

“…The tables are produced by iteratively writing the abundance tables from postprocessing nuclear network calculations and simulating the deflagration in 2D (the same method as used by Fink et al 2010, for detonations andOhlmann et al 2014, for deflagrations). Thermal neutrino losses are also included in the simulations using the formulae by Itoh et al (1996), as described in Seitenzahl et al (2015).…”

Manganese spread in Ursa Minor as a proof of sub-classes of type Ia supernovae

“…In sub-Ch SNe Ia, Mn is mostly synthesised in incomplete Si-burning, and therefore the Mn yields should depend on metallicity. We include this effect as M(Mn) ∝ Z 3 as in the calculations of Seitenzahl et al (2015) and Yamaguchi et al (2015).…”