TY - JOUR
T1 - Sub-Chandrasekhar-mass detonations are in tension with the observed t0-MNi56 relation of type Ia supernovae
AU - Kushnir, Doron
AU - Wygoda, Nahliel
AU - Sharon, Amir
N1 - We thank Stan Woosley, Stéphane Blondin, Ken Shen, Eduardo Bravo, and Stuart Sim for sharing their ejecta profiles with us and for useful discussions. We thank Boaz Katz, Subo Dong, Dean Townsley, and Borxton Miles for useful discussions. DK is supported by the Israel Atomic Energy Commission – The Council for Higher Education – Pazi Foundation – and by a research grant from The Abramson Family Center for Young Scientists. We thank K. Shen for providing us with the results of the lower resolution calculations.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Type Ia supernovae (SNe Ia) are likely the thermonuclear explosions of carbon–oxygen (CO) white-dwarf (WD) stars, but their progenitor systems remain elusive. Recent studies have suggested that a propagating detonation within a thin helium shell surrounding a sub-Chandrasekhar mass CO core can subsequently trigger a detonation within the core (the double-detonation model, DDM). The outcome of this explosion is similar to a central ignition of a sub-Chandrasekhar mass CO WD (SCD). While SCD is consistent with some observational properties of SNe Ia, several computational challenges prohibit a robust comparison to the observations. We focus on the observed t0−MNi56 relation, where t0 (the γ-rays’ escape time from the ejecta) is positively correlated with MNi56 (the synthesized 56Ni mass). We apply our recently developed numerical scheme to calculate SCD and show that the calculated t0−MNi56 relation, which does not require radiation transfer calculations, converges to an accuracy of a few per cent. We find a clear tension between our calculations and the observed t0−MNi56 relation. SCD predicts an anticorrelation between t0 and MNi56, with t0≈30d for luminous (MNi56≳0.5M⊙) SNe Ia, while the observed t0 is in the range of 35−45d. We show that this tension is larger than the uncertainty of the results, and that it exists in all previous studies of the problem. Our results hint that more complicated models are required, but we argue that DDM is unlikely to resolve the tension with the observations.
AB - Type Ia supernovae (SNe Ia) are likely the thermonuclear explosions of carbon–oxygen (CO) white-dwarf (WD) stars, but their progenitor systems remain elusive. Recent studies have suggested that a propagating detonation within a thin helium shell surrounding a sub-Chandrasekhar mass CO core can subsequently trigger a detonation within the core (the double-detonation model, DDM). The outcome of this explosion is similar to a central ignition of a sub-Chandrasekhar mass CO WD (SCD). While SCD is consistent with some observational properties of SNe Ia, several computational challenges prohibit a robust comparison to the observations. We focus on the observed t0−MNi56 relation, where t0 (the γ-rays’ escape time from the ejecta) is positively correlated with MNi56 (the synthesized 56Ni mass). We apply our recently developed numerical scheme to calculate SCD and show that the calculated t0−MNi56 relation, which does not require radiation transfer calculations, converges to an accuracy of a few per cent. We find a clear tension between our calculations and the observed t0−MNi56 relation. SCD predicts an anticorrelation between t0 and MNi56, with t0≈30d for luminous (MNi56≳0.5M⊙) SNe Ia, while the observed t0 is in the range of 35−45d. We show that this tension is larger than the uncertainty of the results, and that it exists in all previous studies of the problem. Our results hint that more complicated models are required, but we argue that DDM is unlikely to resolve the tension with the observations.
U2 - https://doi.org/10.1093/mnras/staa3017
DO - https://doi.org/10.1093/mnras/staa3017
M3 - مقالة
SN - 0035-8711
VL - 499
SP - 4725
EP - 4747
JO - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
JF - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
IS - 4
ER -