Timeline for The two channels of Type Ia SNe and their use as standard candles
Current License: CC BY-SA 4.0
16 events
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| Jan 26, 2022 at 20:52 | history | edited | ProfRob | CC BY-SA 4.0 |
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| Jan 26, 2022 at 10:24 | comment | added | zibadawa timmy | For what it's worth, here's a 2016 paper about super Chandrasekhar mergers of white dwarfs. The ones they modeled don't end in supernovas, but end up collapsing into a neutron star or possibly other forms of dwarf remnant. Basic idea seems to be that off-center burning initiates before the core ignites and does not trigger explosive run-away fusion (then there's a sequence of core burning to off-center burning etc.). Neat. | |
| Jan 26, 2022 at 10:05 | history | edited | ProfRob | CC BY-SA 4.0 |
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| Jan 26, 2022 at 9:49 | comment | added | zibadawa timmy | @ProfRob Ah, I somehow missed the prominent "super Chandrasekhar" blob right at the top. | |
| Jan 26, 2022 at 9:48 | comment | added | ProfRob | There are outliers in the plot - the one discussed in the New Scientist article is in the top-left group of 3. But none of these outliers are conclusively explained. Since most people believe DDs form a large fraction of type Ia SNe then a corollary is that most DD supernovae must look very similar to SD supernovae. @zibadawatimmy I believe a possible problem with your scenario is that it could undergo accretion induced collapse to a neutron star, rather than a thermonuclear type Ia SN - but "super Chandrasekhar" candidates are labelled on the plot - there are 6 of them. | |
| Jan 26, 2022 at 9:36 | comment | added | zibadawa timmy | I thought there was supposed to be a scenario, and I think it's the one YiFan is thinking of one way or another, where two white dwarfs collide essentially intact. So instead of one accreting until hitting the limit, they just form one "giant" white dwarf that's well above the limit and then promptly goes boom. | |
| Jan 26, 2022 at 9:33 | comment | added | ProfRob | @YiFan statements in wikipedia should be backed up with references to the original literature - which should be cited if the specific information is used. If they are not, then beware! In this case the relevant paragraph only contains citations to some junior-level lecture notes and a New Scientist article from 2007 both discussing one unusually bright supernova that is an outlier. | |
| Jan 26, 2022 at 9:32 | vote | accept | YiFan | ||
| Jan 26, 2022 at 9:31 | comment | added | YiFan | Well, I mean, it's generally a reasonable starting point for most topics. I guess not in this case. Thanks! | |
| Jan 26, 2022 at 9:30 | comment | added | ProfRob | Wikipedia isn't a source. @YiFan I am not saying there cannot be outliers. You can see there are in the plot. However, my understanding is that there is more scope for sub-Chandrasekhar mass ignition in DD supernovae. | |
| Jan 26, 2022 at 9:29 | history | edited | ProfRob | CC BY-SA 4.0 |
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| Jan 26, 2022 at 9:29 | comment | added | YiFan | I see, so it's not actually true that the DD scenario is not constrained by the Chandrasekhar limit? (That's what I've seen a lot of online sources such as Wikipedia claim.) | |
| Jan 26, 2022 at 9:27 | comment | added | ProfRob | Because the higher mass WD in the pair accretes from the tidally disrupted secondary WD until it reaches the Chandrasekhar limit. @YiFan | |
| Jan 26, 2022 at 9:25 | comment | added | YiFan | Thanks for the insight! What is the reason why the DD scenario still has tightly constrained luminosities? I would have expected that the DD case could reach higher masses than the SD case (because of much more rapid mass accumulation), exceeding the Chandrasekhar mass and causing higher luminosities. Why is this incorrect? | |
| Jan 26, 2022 at 8:15 | history | edited | ProfRob | CC BY-SA 4.0 |
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| Jan 26, 2022 at 7:58 | history | answered | ProfRob | CC BY-SA 4.0 |