Bumpy Light Curves of SuperluminousSupernovae
Elena SorokinaSternberg Astronomical InstituteMoscow University
in collaboration withS.BlinnikovA.TolstovK.Nomoto
Ringberg Workshop 26 July 2017
• SLSNe (Type I (no hydrogen), Type II) are brigher than -21 magnitude in any optical band at the maximum brightness
• Subclasses: SLSN I normal, SLSN I-R, SLSN I - fast, SLSN II-n, SLSN IIn-peculiar, SLSN II-L, SN Ia-CSM • Rise ~ 20-60 d, decline ~ 20-500 d, Erad ~ (1-10) .1051 erg,
rate/CC ~ 0.1%, ~ 100 SLSNe.
Superluminous supernovae (SLSNe)
Superluminous supernovae (SLSNe)
• SLSNe-II: Occur in all galaxies
SLSNe-I: Exclusively in M* < 109.2 M ⊙ , Z < 0.5 Z⊙ galaxies
Gal-Yam 2012
(Perley 2016)
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Hydrogen-poor superluminous supernovae
M.Nicholl et al. 2015 A.Papadopoulos et al. 2015griz pseudobolometric light curves
−40 −20 0 20 40 60 80 100 120Rest-frame days from maximum light
−23
−22
−21
−20
−19
−18
−17
−16
−15
Mgr
iz
2005ap2007bi2008es2010gx2011ke2011kf2012il2013dg
2013hxCSS121015iPTF13ajgLSQ12dlfLSQ14bdqLSQ14moPS1-10bzjPS1-10ky
PS1-11apPTF09cndPTF09cwlPTF10hgiPTF11rksPTF12damSCP06F6SSS120810
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Observational properties of SLSN-I
• Mmax <= − 21m; Lbol,max > 7 · 1043 erg/s.• Typically, they are very blue and emit qiute much inUV range.
• The range of Mmax is not so large (' 1m); the rangeof the slopes after max is quite large.
• V ' 10, 000km/s, starting from maximum.• Many, if not all, of SLSNe has small bump on therising part of the light curve.
• For some of SLSNe-I: H lines in nebular spectrawith v ' 4, 000km/s, R ' 4× 1016cm (iPTF13ehe;Lin+ 2015).
An ideal model must explain all the properties at once.We are still far from the ideal.
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Three scenarios proposed for SLSNe-I
• Pair instability Supernovae, PISN• “Magnetar” pumping (BUT observed magnetars areslowly rotating, and here millisecond periods areneeded)
• Shock interaction with CSM, e.g. as a result ofPulsational pair instability, PPISN
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3 outcomes of pair-instability
Here are only He-core models,labeled by “He” and the mass ofthe core. They all reach pairinstability, subsequentlyexperiencing 1) pulsations
(He48),2) complete disruption (He80), or3) direct collapse (He160).
8.5
8.6
8.7
8.8
8.9
9
9.1
9.2
9.3
9.4
9.5
9.6
9.7
9.8
9.9
10
3 4 5 6 7 8 9 10
log(T
c)
log(ρc)
Fe disintegration
Pair instability
He 48
He 80
He 160
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Bolometric light curve and “magnetar” fit for PTF 12dam,Nicholl+, 2013, simple analytical model by S.Jerkstrand,colored curves – PISN models
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Compact PISN models with Hydrogen lost; Kozyreva+ 2016
0 50 100 150 200 250 30041
42
43
44
45
Time [days]
log
Lb
ol
[erg
s−
1]
P250
PTF12dam
correctedP200
0 100 200 300
−22
−21
−20
−19
−18
−17
mag
nit
ud
e
u
P200
P250
0 100 200 300
−22
−21
−20
−19
−18
−17
gP200
P250
0 100 200 300
−22
−21
−20
−19
−18
−17
Time [days]
r
P200
P250
0 100 200 300
−22
−21
−20
−19
−18
−17
Time [days]
mag
nit
ud
e
i
P200
P250
0 100 200 300
−22
−21
−20
−19
−18
−17
Time [days]
z
P200
P250
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PISN: Kozyreva+ 2014
0 100 200 300 400 500 60041
42
43
44
45
Time, days
250M
SN2010gxslsn Ic
PS1−10bzjslsn Ic
SN2007bislsn Ic
PS1−10kyslsn Ic
PS1−10awhslsn Ic
log
Bo
lom
etr
ic L
um
ino
sit
y
It is clear that at least some SLSNe are not PISN.
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Ejecta–CSM interaction models with modest energy
PISN and magnetar models requires very high explosion energy andextremly high radioactive nickel production.
In many cases, CSM interaction scenario doesn’t require so extremeparameters.
Our Lagrangean 1D code STELLA with multigroup radiative transferallows us to get more economical models.
Sorokina+ 2016, Tolstov+ 2016,2017
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Radiative shock waves: a powerful source of light in SLSNe.Cold Dense Shell, Smith et al. 2008, a cartoon
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STELLA reproduces the range of SLSNe in shock model:2 extreme cases
Explosion energy is just 2 - 4 foe12
Light curve model for SN2010gx
N0
Synthetic light curves for the model N0, one of the best for SN 2010gx,in r, g, B, and u filters compared with Pan-STARRS and PTF observations.Pan-STARRS points are designated with open squares (u, g, and R bands),
PTF points, with filled circles (B and r bands).
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14
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Many SLSNe-I have a pre-maximum bumpNicholl & Smartt 2015
0 10 20 30 40 50 60 70 80 90Rest-frame days
−26
−24
−22
−20
−18
−16
−14
Abs
olut
e m
agni
tude
+ c
onst
ant
LSQ14bdq (g - 4.5 mag)PTF09cnd (g - 3)SN1000+0216 (1600 Å)PS1-10ahf (2900Å - 1.7)
iPTF13ajg (u + 0.5)SNLS 06D4eu (2420Å + 1)PS1-10pm (2840Å + 1.8)SN 2006oz (g + 3.5)
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Some others have many bumps on the declining stage
SLSN-I PTF15esb: bumpy light curveSLSN-I PTF15esb: bumpy light curve
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SN 2015bn – another example of very bumpy SLSN(Nicholl+ 2015). Pre- and post-maximum bumps might havesimilar or differnt origin.
−100 −50 0 50 100 150 200 250Rest-frame days from maximum light
−23
−22
−21
−20
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−18
−17
Abs
olut
e m
agni
tude
z-1i-0.5rg+0.5u+1
15bn: 12dam:-1.4-1.1-0.4+0.3+1
PTF12dam
0 50 100 150 200 250 300 350Rest-frame days from first detection
43
44
log 1
0Lbo
l(e
rgs−1
)
2015bnPTF12dam
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Radioactive origin of pre-maximum bump?
Doubled peak of SLSN-I (by R. Quimby)Doubled peak of SLSN-I (by R. Quimby)
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Some more realistic explanaitions of bumps
• 1st bump - shock break-out through an extended pre-SN envelope,main max - another (whichever) main source of energy.
• Two (or more) subsequent explosions/ejections (quite natural forPPISN scenario – see recent paper by Woosley 2017, with lots ofmodels)
• Stratification of ejected elements along the radius:Innermost layes of CO-rich gas become opaque at lower T, thenphotosphere stalls waiting for helium layers to become opaque athigher T.
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Shock breakout – analytical formula
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Shock breakout looks similar for any energy sourceMagnetar inside:
0 10 20 30 40 50days since explosion
1043
1044
lum
inosi
ty (
erg
s/s)
Msn = 5 M¯
Msn = 10 M¯
Msn = 15 M¯
Msn = 20 M¯
0 10 20 30 40 50days since explosion
1043
1044
Esn =1×1051 ergs
Esn =2×1051 ergs
Esn =3×1051 ergs
0 5 10 15 20 25 30 35 40
days since explosion
1043
1044
lum
inosi
ty (
erg
s/s)
FullThermalization
shocksupernovatotal
0 5 10 15 20 25 30 35 40
days since explosion
1043
1044
InefficentThermalization
Thermal bomb:
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Shock breakout
0 50 100 150 200 250 300time since explosion (days)
43.0
43.2
43.4
43.6
43.8
44.0
44.2
44.4
log
10 b
olo
metr
ic lum
inosi
ty
LSQ14bdqmodel 1model 2
Kasen+ 2016 (Magnetar model) 23
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Two explosions details
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1st piston with E = 4B, then thermal bomb with E = 20B
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Problems with 2-explosion models
It is the easiest model for light curve calculation,BUT it is unclear if it is physically possible to produce 2 energeticexplosion or mass ejection so close in timeand WHY this time delay and brightness ratio of two maxima are sosimilar for many SLSNe.
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Post-shock-breakout cooling, then interaction(or subsequent interactions with several ejections)
Piston expands 8 Msun of He-envelope with E = 1B;density distribution in 1e7 s and 2e7 s
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Then 2nd explosion produces the whole light curve
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Opacities of CO mixture (red) and He (black)
T=7000K T=11000K
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Different composition
Helium C:O=1:1 C:O=9:1
Sorokina+ (2016)
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Pure helium vs. CO/He models
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Conclusions
• Interaction models are able to reproduce both narrow and wide LCsof SLSNe. They require quite large mass of CO-rich material ejectedwithin few months to years before the final explosion. The problemof high velocities will be discussed in the next talk.
• The origin of pre-maximum bumps still remain questionable.• Most natural explanation of the post-maximum bump is theinteraction of SCM layers or bullets.
• The combination of the SLSN scenarios is promising.• The ideal scenario have to explain ALL observational features atonce: LCs including bumps, high velocities, etc.
The work is in progress
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Thank you!
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