Rapidly Fading Supernovae from
Massive Star Explosions
Io Kleiser - Caltech
Advisor: Dan Kasen - UC Berkeley
31 October 2013

SN 2010X Discovery

Normalized Magnitude

010X: A CANDIDATE “.Ia” EXPLOSION
2010X-g
2010X-r
2010X-i
2002bj-r

0
1991T
1991bg

2L99• Extremely rapidly
declining lightcurves!
• Similar shape topeculiar SN 2002bj

1994I

46-20

020Days since Peak

40
Kasliwal et al. 2010

Spectroscopic Comparison with
SN 1994I

Spectroscopic similarity toother SNe Ic suggests asimilar origin, but the light
curves decline much morerapidly than normal Ibc SNeA Small but Growing ClassDiffusion time (Arnett1979):!

−24

45−22!

Luminous Supernovae

10SCP06F6SN2005ap SN2008es PTF09cnd
SN2006gy
PTF10cwr PTF09cwl PTF09atu

1044

SN2007bi−20

Thermonuclear
Supernovae

4310•

Suggests a smallejected mass
as in “.Ia” and similar
models!

Peak Luminosity [MV]

SN2002bj−18
PTF10bhp.Ia Explosions−16Core−Collapse
Supernovae

PTF12bho

SN2007ke
PTF11bij
PTF09dav
PTF11kmb
SN2012hn
PTF10iuv SN2005E

4210Ca−rich Transients
SN2008ha−1441

SN2008S
PTF10acbp

Intermediate
Luminosity
NGC300OT Red
Transients−1240

PTF10fqs
P60−M82OT−081119−10Classical Novae−81010M85 OT
Luminous
V838 Mon
RedNovae
M31 RV

3910P60−M81OT−071213
38−610V1309 Sco

SN 2002bj (Poznanski et al. 2010)!
SN 2010X (Kasliwal et al. 2010)!
SN 2005ek (Drout et al. 2013)−40101

10

Characteristic Timescale [day]210

Peak Luminosity [erg s−1]

•Modeling SN 2010X Light Curves &Spectra with SEDONA
Kleiser & Kasen 2013 submitted to MNRAS,Mon. Not. R. Astron. Soc. 000, 000–000 (0000)
Printed 14 October 2013
(MN L TEX style file v2.2)
arXiv:1309.4088
A

Rapidly Fading Supernovae from Massive Star Explosions
12,3IoK.
W.
Kleiser,andDanielKasen†,
1Department of Astronomy, California Institute of Technology, Pasadena, CA 91125.

2 Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720.
3 Department of Physics, University of California, Berkeley, CA 94720.

14 October 2013•••

Parameterized
1D simulations in homologous expansion!
ABSTRACTTransient surveys have recently discovered a class of supernovae (SNe) with extremelyrapidly law
declininglight curves.
These events are also often relatively faint, especiallyBroken power
density
structure!
compared to Type Ia SNe. The common explanation for these events involves a weak
explosion, producing a radioactive outflow with small ejected mass and kinetic energy
Uniform composition
layers:O/Ne-richandHe+solar)(M 0.1 M and(twoE 0.1
B, respectively),
perhapsfromthe detonation of a helium
shell on a white dwarf. We argue, in contrast, that these events may be Type Ib/cSNe with typical masses and energies (M 3 M , E 1 B), but which ejected very
little radioactive material. In our picture, the light curve is powered by the diffusionof thermal energy deposited by the explosion shock wave, and the rapid evolution isProblems with the “.Ia” Modelï12=olog density (g/cm3)

ï12.5
ï13
ï13.5
ï1400
13

10o= 1o=.10o=o=

2

ï15.5

10.
00
ï1log optical depth
0.5

1
1.5
temperature (104 K)

No radioactive tail seen
(could be below limits;
could be little -raytrapping)!

•Deep oxygen features
require a large O mass (), larger than the total“.Ia” ejected mass of1

ï14.5
ï15•

2

ï2

Different Approach: Core-Collapse
Model with Recombination•If little or no nickel ispresent, the luminosity
could be due to the
diffusion of thermal energy
deposited in the explosion
shock!

•O recombination allows
radiation to be released
more rapidly!

•This is analogous to a TypeII “plateau”(see Ensman &Woosley 1988, Dessart
et al. 2011)

Model Light Curves
SN 2010X data;
representative modelfit; Type Ic SN 1994I
for comparison

ï18absolute magnitude

ï17

ï16

Model parameters:!

ï15

ï14

ï13

ï120!

model rmodel gmodel i
94I U
94I B
94I V
94I R
94I I5!
!
101520time (days)

25

30

35

Dominantly O, Ne,Mg in composition

Model Spectrum

3

data 24 dmodel 24 dscaled flux

2.5
OI

2
1.5
1
0.5
0
4000

5000

6000

7000
wavelength (angstroms)

8000

9000

O/Ne/Mg-rich ejecta + thin He/solar outer layer

10000Spectral Time Series
18

modeldata

16
14

Color evolution isfaster in model spectrathan in data, but mostmajor features arereproduced!

•Discrepancies may be
due to simplicity of the1D uniformcomposition model andpotentially could be
reduced with finer
tuning

10 d9d10 d12scaled flux + constant•1024 d

17 d

824 d

6436 d
31 d

247 d
0
3000

4000

5000

6000 7000 8000 9000
wavelength (angstroms)

10000 11000

Hiding Radioactive Nickel

Large Presupernova Radii

2

E. Quataert & J. Shiode

Table 1. Late Stages of Massive Stellar Evolution
StageCarbon
Neon
Oxygen
SiliconDuration (tnuc )⇧ 103 yr
⇧ 1 yr⇧ 1 yr⇧ 1 day

Lfusion (L⇥ )
⇧ 106
⇧ 109
⇧ 1010⇧ 1012

Mach (Mconv )⇤c (s)⇧ 0.003⇧ 0.01⇧ 0.02⇧ 0.05⇧ 104.5
⇧ 103
⇧ 103
⇧ 102

Fusion luminosities, durations, convective Mach numbers, and convectiveR ⌃ 1700 R⇥ , T eff ⌃ 4000 K, and Lphoton ⌃ 105.8 L⇥ ). The
evolved using the MESA 1D stellar evolution code (P2011) with no mass loss. Convective boundaries are det
the Schwarzschild criterion, and hydrogen- and non-bu
vection zones have overshooting of 1% of the local preheight.
Thisprogenitor &choice
is somewhat
Seee.g.
Quataert
Shiode2012arbitrary alikely to actually be the optimal progenitor for wave-dloss. We include this model to provide a quantitative

Summary•

SN 2010X and similar SNe (SN 2002bj, SN 2005ek, others upcoming) are
generally thought to be small-mass explosions, perhaps related to the “.Ia”
model!

•

Lack of a visible radioactive tail is difficult but not impossible to accommodatein these models!

•Particularly, prominent oxygen features suggest that a large ejected mass isneeded!

•We explore core-collapse models in which little or no radioactive material ispresent in the ejecta—recombination allows for higher masses (O plateau)!

•Parameterized radiative transfer calculations agree with the data, but moredetailed modeling is required to understand the progenitors!

•How can we avoid ejecting radioactive nickel?!

•

How can we expand progenitor radii enough to achieve observed luminosities?

Host Galaxies

OVA 2010X: A CANDIDATE “.Ia” EXPLOSION

0sorbed6 M⊙ ,c light

L101

Figure 5. Left: R-band image of NGC 1573A, the host of SN 2010X, taken withHostsof SN2010X(left)
SN 2002bj
the Large Format
Cameraon thePalomar
200 andinch telescope.
Right: sum of allavailable Deepsky (Nugent 2009; we note that the six photons in the XRT HPD(right) are both star-forming galaxies andPSF of 0.′′ 3 are likely from the galaxy nucleus) images of NGC1821, the host of
do not constrain the progenitors
SN2002bj.
(A color version of this figure is available in the online journal.)Kasliwal et al. 2010

SN 2010X Spectrum SYNOW Fit+10 days)
g−r = 1.2
SYNOW
common b
The primaand preseof SN 200
find that thfor SN 20
Fe ii impro
SN 2002b

The exc
SN 2010X
supernovathe two dtime19 (τr(τd ≈ 5 daFigure 3. SYNOW fit to the Keck spectrum (+23 days) of SN 2010X. LinesThe p
contributed by each Typeion areIcshown.
withshowing(purple) andwithout (red) iron arelight Fits
curvestrong!
L=1
peak
overplotted on the data (blue). Top panel: the dilemma of whether SN 2010X
featuresof C,O, Ca The vertical dashed lines
12,000 km
has helium or a combination ofsodium andaluminum.
accept vs ≈show helium at 9500 km s−1 . In non-LTE, the singlet transition ofλ6678 may
Kasliwal
et al. 2010
be suppressed relative to the λ7065 and λ5876 triplet transition helium lines.
The rise(A color version of this figure is available in the online journal.)Degeneracy in the Model
M ej•

These three parameters
can be adjusted to fit awide range of Ni-freelight curves!
SN 2010X can also be fit
with othercombinations of values(lower right panel)

E 51

ï16
ï14
ï12
ï10
ï8
ï18

absolute magnitude•

absolute magnitudeï181 M⊙
3 M⊙
5 M⊙
10 M ⊙

0.1 B
0.5 B
5.0 BR0

ï16
ï14

Me j = 6 M⊙
E51 = 3 B

ï12ï10ï80

R 0 = 9 × 10 1 1 cm

10 11 cm
10 12 cm
10 13 cm
1020
time (days)

rgi
30

01020
time (days)

30