Observational Constraints on
Progenitors and Explosions of Type Ia Supernovae
Keiichi Maeda (Kyoto U.)
Progenitors – which or even something else?
MS + MS
w/o (2nd) Common Envelope
w/ Common Envelope
Single Degenerate (SD)
WD + MS/RG
Double Degenerate (DD)
WD + WD
+ Other variants (e.g., Core-degenerate: WD + AGB)
Key point 1: “Unbiased” Summary
No consistent solution (for
normal SNe Ia) so far.
Key point 2: “Biased” Summary
It is no more like “SN Ia
progenitor style fist fight”.
Emerging diversity seems too much to be
explained by a single population.
Perhaps (more likely?) a mixture.
Progenitors – from a different viewpoint
Chandrasekhar mass WD (Ch. WD)
Density & temperature increase due to cooling and
contraction, igniting thermonuclear runaway near the center.
pros: No need of external process.
Observed “uniformity”.
cons: How to feed a WD to the Ch. WD.
Deflagration to Detonation Transition?
Observed “diversity”?
Sub-Chandrasekhar mass WD (Sub-Ch. WD)
External process to trigger the runaway.
pros: No need to glow a WD much (potentially abundant).
Observed “diversity”.
cons: Need external push.
Observed “uniformity”?
Single Degenerate (SD)
C+O WD + MS/RG
Chandrasekhar WD + MS/RG
C+O WD + He star
- Delayed Detonation
(C burn deep inside WD)
- Failed/Weak Deflagration
(only deflagration, no detonation)
- etc (e.g., pulsational detonation)
“Delayed” (e.g., spin-up/down)
Sub-Ch. WD + He star
Ch. WD + He WD
- Double Detonation
- Delayed Detonation
(He flash on the surface of WD) - Failed/Weak Deflagration
- etc.
Double Degenerate (DD)
C+O WD + C+O WD
Explosion at merging
C+O WD + He WD
- Violent merger
(C burn on the surface of WD)
“Survive”
Viscous/Thermal evolution
(100 secs to 1000 yrs)
ONe WD←envelope/disk
Sub-Ch. WD + He WD
- No SN explosion (NS formation)
- Double Detonation
(He flash on the surface
of WD)
Ch. C+O WD←envelope/disk
- Delayed Detonation?
- Failed/Weak Deflagration?
(Theories predict ONe WD, not SN:
Saio, Yoon, Shen, …)
Expected Observables
CSM
Companion
SD
DD
Delayed-SD
SD
DD
Delayed-SD
Del-Det.
MS or RG
None/He WD
CSM
Weak Def.
MS or RG
None/He WD
None
(vicinity?)
Doub.-Det.
He
None/---
Violent
---
None/---
WD mass & Explosion
SD & DD
Ejecta Structure
Del-Det.
Ch. (or Super.-Ch.)
Quasi-spherical
Weak Def.
Ch. (or Super.-Ch.)
Quasi-spherical (clumpy)
Doub.-Det. Sub.-Ch.
Quasi-spherical?
Violent
Highly Asymmetric
“Sub-Ch.” for nucleosynthesis
“Ch./Sup.-Ch.” for total mass
Explosion and Nucleosynthesis
KM+ 10
Kromer+ 13
Seitenzahl+ 13
Chandra vs. Sub-Ch.
“WD density”
Stable/unstable n-rich
Fe-peaks more abundant
in Chandra-mass WD
Fink+ 10
Tanikawa, … KM+ 15
Roepke+ 12
Many works (e.g., Khokhlov, Hoeflich, Bravo, Woosley, Kasen, Iwamoto, Nomoto, …)
Normal SNe: Companions in pre-SN/SNRs
LMC SNR 0509-67.5: Against RG/MS
Schafer & Pagnotta 2010
RG González Hernández+ 2012
SN 1006: Against
Tycho: Controversial
Ruiz-Lapuente+ 2004, …
Li+ 2011
SN 2011fe: Against RG down to ~ 1 M
SN 2014J: Against RG down to ~ 1 M
and some He donor
Kelly+ 2014
So far, seems to disfavor SD for normal SNe Ia.
No Crush of the SN ejecta w/ SD companion?
2011fe
V
Kasen 2010
(cf. Kutsuna &
Shigeyama)
2013dy
Nugent+ 2011
Zheng+ 2013
SN Ia 2012ht
Yamanaka, KM+ 2014
Liu, …, KM+, 2013
And very good limits by the Kepler (KEGS, red band: Olling+ 15)
Individual SNe and systematics search (e.g., SDSS-II: Hayden+ 10)
Crush of the SN ejecta w/ SD companion?
sub-luminous
iPTF14atg
Cao+ 2015
First detected for an
outlier, but then for
normal.
Observed only for a
specific direction?
normal
SN2012cg
Marion, … KM+ 2016
Examples with possible signatures
Back in the history of ~ 100 day x (VSN/Vmass-loss) ~ 30 yrs
(~ 0.01 pc)
No Crush into CSM (normal SNe)
Tight limit for SN 2011fe (<0.01pc):
Mdot/vw < ~10-8Myr-1/100km s-1
Radio
Chomiuk+ 2012
X-ray
Margutti+ 2012
Radio: Synchrotron
X-Ray: Inverse Compton (+ thermal)
Back in the history of ~ 100 day x (C/Vmass-loss) ~ 300 yrs
(~ 0.1 pc)
No echo by CS Environment (normal)
2006X
Symbiotic
Model (SD)
No CS-dust echo seen in (normal) SNe Ia.
There is little CSM (dust) at R < 0.5pc.
KM, Nozawa, Nagao, Motohara 15
SN properties favor the delayed detonation?
Delayed-Detonation
Violent Merger
Roepke+ 12
Polarization
Bulla+ 16
Violent
Merger
Obs.
Violent merger produces too much diversity (in my opinion).
Ch. or sub-Ch. WD?
“Tomography”
suggests uniform Mej
1D, Ch. + sub-Ch.
Blondin+ 16 (conference talk)
Fe + IME ~ 1 M
+C/O ~ 1.4M
Mazzali+ 07
Brighter ⇔ Fainter
3D, delayed-det.
(Ch.)
Sim+ 13
Chandra or sub-Chandra WD?
• Chandra WD (high-ρ) produces n-rich stable/unstable Fe-peaks.
←Stable n-rich Fepeaks (e.g., 58Ni)
SN 2012cg
Generally favors
Chandra-WD.
Chandra
KM+ 10
Chandra
Mn/Fe
Unstable Fe-peaks
from late-time lum.→
(but Kerzendorf+ 17)
Sub-Ch.
Graur+ 15
SN 2011fe
Chandra
Sub-Ch.
SN Remnant
Yamaguchi+ 15
Sub-Ch.
Ni/Fe
Shappee+ 16
What about “outliers”
KM, Terada 2016
Maybe a mixuture of
different
evolutionary paths
and explosion
modes
Ia-CSM: Crush into CSM
Dilday+ 2012
Taddia+ 2012
SNe Ia colliding with CSM shells? (← Single degenerate)
Associated SNe are SN
1991T-like (bright SNe Ia)
Leloudas+ 2015
A Link between 91T-like and Ia-CSM
Ia-CSM
91T
Kepler
Kepler SN Remnsnt
Katsuda, Moti, KM+ 2015
Ejecta abundance & hist. LC
⇒SN type: bright 91T-like
CSM amount + distribution
⇒Mass loss history:
> 0.3M @ 2pc (104-5 yrs)
PTF 11kx ~ M 0.01pc
(Ia-CSM) (~ 100 – 1000 yrs)
Over-luminous Ia (Super-Chandra WD?)
2M
1.4M
SN 2006gz
KM+ 2009
Prototypical: SN
2009dc
Yamanaka, Tanaka+ 2009
Two populations?
Luminous & low-vel
SNLS-03D3bb (Howell+ 06)
SN 2009dc (Yamanaka+ 09)
Not-so-luminous & high-vel
Bright, M(56Ni) > 1M.
Mej > 1.4M: “Super Chandra WD”
SN 2006gz (Hicken+ 07)
SN 2012dn (Chakradhari+14,
Parrent+16)
Echo by CS environment (over-luminous Ia)
Yamanaka, KM+ 2016
Nagao, KM, Yamanaka 2017
100 d
Pure echo (obs – SN)
Observer
2012dn
2009dc
2001el
0.04pc
ρ∝r-2
Discovery of bright & Long-lasting NIR emission.
“Plateau-like evolution, ~ 1,000K thermal emission”
← As predicted for a CS echo (KM+ 2015)
⇒ More sophisticated model: geometry, etc (Nagao+ 2017).
~ 4 10-6 M yr-1 ⇒ SD for overluminous SNe?
Type Iax (2002cx-like)
Jha+
07
Faint, narrow lines
Li+ 03
Many works (Phillips, Foley, Stritzinger, Szalai, Tomasella, Sahu,
Yamanaka, …)
Progenitor/companion (or compact remnant)?
McCully+ 2014
SN “Iax” 2012Z: He donor? He star progenitor?
SN “Iax” 2008ha: Red source (post-SN). Foley+ 2014
Small mass & energy: Failed Deflagration?
Vsi
~1.4M
WD remnant
Foley+ 13
~0.2-1M
Eejcta
Kromer+ 13
Mej
Δm15
1.4M
Arnett-type model
See:
Evolution of
remnant WD:
Shen+ 16
1.2x1051erg
Fink+ 14
Enuc
Late-time behavior: something left?
SN 2014dt: Very nearby SN Iax.
Kawabata, Kawabata, KM+ submitted
5700K@40d
SN Iax 2014dt
NIR
IR
Late phase
3700K@>130d
λ
50
100d
Thermal continuum even in the late-phses.
Temperature stop evolving at ~ 60 days, when LC flattened.
Late-time LC follows 56Co-decay, full-trapping.
Non-expanding opaque component? Remnant WD?
See a review by KM & Terada (2016) arXiv:1609.03639
Summary & Remarks
• Diversities may reflect different paths.
– Normal SNe Ia:
• Companion/CSM favor DD, while SN properties favor
Chandrasekhar WD & delayed detonation, in observations.
• However, Chandrasekhar WD explosion from the DD is not
(yet?) successful in theory (ONe WD formation).
• Something must be missing (either theory or obs, or both).
– Outliers:
• Favors SD? CSM in Ia-CSM (and link to 91T) and in overluminous SN 2012dn. Companion/remnant WD in Iax?
• Can be accommodated in evolution theory?
– SD and DD are mutually exclusive (common envelope)!