scholarly journals The number of progenitors in the core-degenerate scenario for Type Ia supernovae

2012 ◽  
Vol 428 (1) ◽  
pp. 579-586 ◽  
Author(s):  
Marjan Ilkov ◽  
Noam Soker
2018 ◽  
Vol 14 (S343) ◽  
pp. 540-541
Author(s):  
Bo Wang

AbstractWD+AGB star systems have been suggested as an alternative way for producing type Ia supernovae (SNe Ia), known as the core-degenerate (CD) scenario. In the CD scenario, SNe Ia are produced at the final phase during the evolution of common-envelope through a merger between a carbon-oxygen (CO) WD and the CO core of an AGB secondary. However, the rates of SNe Ia from this scenario are still uncertain. In this work, I carried out a detailed investigation on the CD scenario based on a binary population synthesis approach. I found that the Galactic rates of SNe Ia from this scenario are not more than 20% of total SNe Ia due to more careful treatment of mass transfer, and that their delay times are in the range of ∼90 − 2500 Myr, mainly contributing to the observed SNe Ia with short and intermediate delay times.


2020 ◽  
Vol 499 (4) ◽  
pp. 4725-4747
Author(s):  
Doron Kushnir ◽  
Nahliel Wygoda ◽  
Amir Sharon

ABSTRACT 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 $t_0\approx 30\, \textrm{d}$ for luminous ($M_\text{Ni56}\gtrsim 0.5\, \mathrm{ M}_{\odot }$) SNe Ia, while the observed t0 is in the range of $35\!-\!45\, \textrm{d}$. 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.


Author(s):  
R Pakmor ◽  
Y Zenati ◽  
H B Perets ◽  
S Toonen

Abstract Normal type Ia supernovae (SNe) are thought to arise from the thermonuclear explosion of massive (>0.8 M⊙) carbon-oxygen white dwarfs (WDs), although the exact mechanism is debated. In some models helium accretion on to a carbon-oxygen (CO) WD from a companion was suggested to dynamically trigger a detonation of the accreted helium shell. The helium detonation then produces a shock that after converging on itself close to the core of the CO-WD, triggers a secondary carbon detonation and gives rise to an energetic explosion. However, most studies of such scenarios have been done in one or two dimensions, and/or did not consider self-consistent models for the accretion and the He-donor. Here we make use of detailed 3D simulation to study the interaction of a He-rich hybrid 0.69 M⊙ HeCO WD with a more massive 0.8 M⊙ CO WD. We find that accretion from the hybrid WD on to the CO WD gives rise to a helium detonation. However, the helium detonation does not trigger a carbon detonation in the CO WD. Instead, the helium detonation burns through the accretion stream to also burn the helium shell of the donor hybrid HeCO-WD. The detonation of its massive helium shell then compresses its CO core, and triggers its detonation and full destruction. The explosion gives rise to a faint, likely highly reddened transient, potentially observable by the Vera Rubin survey, and the high-velocity (∼1000 kms−1) ejection of the heated surviving CO WD companion. Pending on uncertainties in stellar evolution we estimate the rate of such transient to be up to $\sim 10{{\ \rm per\ cent}}$ of the rate of type Ia SNe.


2015 ◽  
Vol 450 (3) ◽  
pp. 2948-2962 ◽  
Author(s):  
G. Aznar-Siguán ◽  
E. García-Berro ◽  
P. Lorén-Aguilar ◽  
N. Soker ◽  
A. Kashi

2011 ◽  
Vol 7 (S281) ◽  
pp. 72-75 ◽  
Author(s):  
Noam Soker

AbstractIn the core-degenerate (CD) scenario for the formation of Type Ia supernovae (SNe Ia) the Chandrasekhar or super-Chandrasekhar mass white dwarf (WD) is formed at the termination of the common envelope phase or during the planetary nebula phase, from a merger of a WD companion with the hot core of a massive asymptotic giant branch (AGB) star. The WD is destroyed and accreted onto the more massive core. In the CD scenario the rapidly rotating WD is formed shortly after the stellar formation episode, and the delay from stellar formation to explosion is basically determined by the spin-down time of the rapidly rotating merger remnant. The spin-down is due to the magneto-dipole radiation torque. Several properties of the CD scenario make it attractive compared with the double-degenerate (DD) scenario. (1) Off-center ignition of carbon during the merger process is not likely to occur. (2) No large envelope is formed. Hence avoiding too much mass loss that might bring the merger remnant below the critical mass. (3) This model explains the finding that more luminous SNe Ia occur preferentially in star forming galaxies.


1998 ◽  
Vol 301 (2) ◽  
pp. 405-413 ◽  
Author(s):  
D. J. R. Wiggins ◽  
G. J. Sharpe ◽  
S. A. E. G. Falle

2016 ◽  
Vol 464 (4) ◽  
pp. 3965-3971 ◽  
Author(s):  
B. Wang ◽  
W.-H. Zhou ◽  
Z.-Y. Zuo ◽  
Y.-B. Li ◽  
X. Luo ◽  
...  

1998 ◽  
Vol 492 (1) ◽  
pp. 228-245 ◽  
Author(s):  
P. Hoflich ◽  
J. C. Wheeler ◽  
A. Khokhlov

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