Ryosuke Hirai Waseda University
Workshop on “The Progenitor-Supernova-Remnant Connection” @Ringberg Castle, Germany 24th July 2017 Discovered by the Intermediate Palomar Transient Factory The ONLY SNIb with Pre-SN image taken by HST
Discovery 16/6/2013 Cao et al. 2013 Galaxy NGC 5806 SN type Ib
EldridgePre- SNet al. flux 2015 Folatelli et al. 2016 Cao et al. 2013
Pre-SN image! Pre-SN Allowed region for primary
+extinction, distance uncertainty
Light Curve
푀푒푗 ∼ 1.9푀⊙ ⇒ 푀푝푟표푔~3.5푀⊙ (Bersten et al.2014) Progenitor should have been
≃3.5M⊙ He star！ How was the progenitor formed? Binary interaction necessary to produce a ≃3.5M⊙He star （Wolf Rayet models ≳8M⊙）
Bersten et al.2014
A massive companion should be found 3 years after explosion!
Primary mass Final companion mass Mass ratio [M⊙] [M⊙] 푓 푖 푖 푖 23 ≲ 푀2 ≲ 45 훽 = 1 15 ≲ 푀1 ≲ 25 0.8 ≲ 푀2 푀1 ≲ 0.95 푓 18 ≲ 푀2 ≲ 45 훽 = 0.5 How does the companion look if it is heated by the ejecta? (Hirai et al. 2015)
initial Final
푀1 19 M⊙ 3.5 M⊙
푀2 18 M⊙ 33.5 M⊙ Period 2.45 d 61.7 d How does the companion look if it is heated by the ejecta? (Hirai et al. 2015)
Bound region initial Final
푀1 19 M⊙ 3.5 M⊙
푀2 18 M⊙ 33.5 M⊙ Input the progenitor into a Period 2.45 d 61.7 d hydrodynamic simulation code How does the companion look if it is heated by the ejecta? (Hirai et al. 2015)
SN
Bound region initial Final
푀1 19 M⊙ 3.5 M⊙
푀2 18 M⊙ 33.5 M⊙ Input the progenitor into a Period 2.45 d 61.7 d hydrodynamic simulation code How does the companion look if it is heated by the ejecta? (Hirai et al. 2015)
SN
initial Final
푀1 19 M⊙ 3.5 M⊙
푀2 18 M⊙ 33.5 M⊙ Input the progenitor into a Period 2.45 d 61.7 d hydrodynamic simulation code The companion expands by the heat, and may change its appearance (temperature, luminosity)
Previous Our prediction prediction
Answer should be revealed three years after the explosion!!
Hirai et al. 2015 No companion found (yet)!!
Folatelli et al. 2016
At least the companion is not an O-star large 푞 binary small 푞 binary
stable RLOF common envelope
time Pre-SN
He star + massive star He star + small star
supernova supernova 푀푒푗 ∼ 1.9푀⊙
present NS + massive star NS + small star
Bersten et al. 2014 etc Eldridge et al. 2016 etc Pre-SN Allowed region for primary
>30R⊙
+extinction, distance uncertainties Forbidden region for companion Present large 푞 binary small 푞 binary
stable RLOF common envelope
time Pre-SN
He star + massive star He star + small star
supernova supernova 푀푒푗 ∼ 1.9푀⊙
present NS + massive star NS + small star
Bersten et al. 2014 etc Eldridge et al. 2016 etc Ohlmann et al. 2016
Highly efficient ・orbital shrinkage ・envelope stripping Numerical Procedure Single-star evo. ② ① Evolve a star up to the RG phase. ① ② Remove the envelope artificially. ③ ③ Evolve up to core-collapse. Artificial CE evo.
Consistent Results with pre-SN image!! “α-formalism” (Webbink 1984)
퐺푚1푚2 퐺푚1,푐푚2 퐸푒푛푣 = 훼퐶퐸 − + 2푎푖 2푎푓
2푎푖 Common 푚 푚2 푚1,푐 2푎 푚2 1 envelope 푓
훼 : efficiency of envelope ejection 훼퐶퐸 represents the energy 퐶퐸 reservoir for envelope ejection (typically taken as ~1) 퐸푒푛푣: binding energy of the ejected envelope Pre-explosion radius large 푞 binary small 푞 binary
stable RLOF common envelope
time Pre-SN
He star + massive star He star + small star
supernova supernova 푀푒푗 ∼ 1.9푀⊙
present NS + massive star NS + small star large 푞 binary small 푞 binary
stable RLOF common envelope
time Pre-SN
He star + black hole He star + small star
supernova supernova 푀푒푗 ∼ 1.9푀⊙
present NS + black hole NS + small star Simulate binary evolution with a black hole
Parameter region
푚1 = 15 − 17Mʘ 푚2/푚1 > 0.8 푃~4 − 20d
Leaves a wide BH-NS binary
(Hirai 2017) How was the progenitor formed? black hole How was the progenitor formed? large 푞 binary small 푞 binary
stable RLOF common envelope
time Pre-SN
He star + black hole He star + small star
supernova supernova 푀푒푗 ∼ 1.9푀⊙
present NS + black hole NS + small star Let us clarify the properties of the binary we want to produce
Secondary BH(Primary) Mass: 14-17Msun Mass: >11Msun Metallicity:Z=0.02
Orbit Separation: ≳50Rsun Stellar evolution theory Heger et al. 2003
20 25 ZAMS mass (M⊙) Sukhbold et al. 2016
Supernova observations 25 40 ZAMS mass (M⊙)
Observed progenitor masses suggest
that Dostars dooo with 18 M⊙ ≲MZAMS≲25 M⊙ do not explode (?)
Stars with mass >18M⊙ Smartt et al. 2009 all collapse to BHs large 푞 binary small 푞 binary
stable RLOF common envelope time
He star + massive star He star + massive star
collapse collapse
BH+massive star BH+massive star
14 − 17Mʘ 14 − 17Mʘ time
Post-CE sep.
He core mass Post-CE and Pre-SN separation ① How was the progenitor of iPTF13bvn formed? • Common envelope scenarios are unlikely. • The progenitor was a 14-17M⊙ star and likely had a large black hole companion (ULX-like binary).
② How was the black hole of iPTF13bvn formed? • The binary separation at the onset of the XRB phase should be >50R⊙ • The binary started with a >70M⊙ primary and experienced a common envelope phase. • Such binaries only consist <0.1% of the whole stellar population so iPTF13bvn may have been a rare event.