Do we still need to search
for supernovae ?
Enrico Cappellaro
Osservatorio Astronomico di Padova
Istituto Nazionale di Astrofisica
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
Talk Outline
• SN Ia are the best luminosity distance
indicators on cosmological scale
o for precision cosmology we need to
understand SN Ia diversity
• Stars with mass >8 M end their life as core
collapse supernovae
o stripped-envelope SNe and GRBs
o progenitor mass and explosion outcome
o mass loss history in massive stars
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
Basic SN classification
max.
+10 months
Ia
Ib
II
52° Congresso SAIt
Scenario
3 - 8 M Thermonuclear
explosion of WD in binary
system
30 - 60 M core-collapse of
massive star after strong mass
loss
8 - 40 M core-collapse of
massive star after
low/moderate mass loss
Teramo, 4 - 8 Maggio 2008
Precision cosmology
with SN Ia
SNAP collaboration
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia, are they standard candles
?
Δm15
1.5 mag
52° Congresso SAIt
< 1.0
1.0 - 1.3
1.0 - 1.7
> 1.7
Teramo, 4 - 8 Maggio 2008
absolute magnitude
SN Ia, are they standard candles
?
-20
max
Δm15
-18
15d
-16
0
40
days from maximum
52° Congresso SAIt
Altavilla et al. 2004 MNRAS 349, 1344
Teramo, 4 - 8 Maggio 2008
SN Ia, are they standard candles
?
Prieto et al. 2006 ApJ 647, 501
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia explosion models:
carbon deflagration in a C-O white dwarf
(W7)
Branch etal.1985
AGB
Nomoto etal. 1984
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
Modeling SN Ia
ejecta tomography
Mazzali et al. 2008 MNRAS in
press
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
Modeling SN Ia
ejecta tomography
2004eo
W7
Mazzali et al. 2008
MNRAS in press
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
stratification
SN Ia diversity
Benetti et al 2005 ApJ 623, 1001
Ni mass
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia diversity
The
orro mark
vs m15(B)  σ~0.13M
+ 54Fe & 58Ni  σ~0.09M
56Ni
outer vel NSE ≈ inner vel IME
IME shell encloses ≥ 1.05±0.09 M
irrespective of m15(B)
~0.09Msun
~0.13Msun
 less 56Ni corresponds to more
IME for a similar total mass
Mazzali et al. 2007 Science 315, 825
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia explosion models
Ropke et al. 2007
Deflagration
spots
5
20
800
M(NSE)
1.14
0.83
0.64
M(IME)
0.22
0.44
0.55
Weak deflagration
leaves fuel at high
density which is
burned to NSE by
detonation
52° Congresso SAIt
Strong deflagration
exhausts fuel and
expands the star.
Detonation at lower
density makes IME
Teramo, 4 - 8 Maggio 2008
Not the end of the story ….
The type Ia supernova SNLS-03D3bb from a
super-Chandrasekhar mass white dwarf star (2 M)
Howell et al 2006 Nature 433, 308
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia precursor scenarios
single or double degenerate ?
The collapse of a stripped-envelope massive star in a dense environment ?
Benetti et al. 2006 ApJ 653, L129
SN2002ic: evidence for an
asymptotic giant branch star in the
progenitor system of a type Ia SN
(Hamuy et al 2003 Nature 424, 651)
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia precursor scenarios
single or double degenerate ?
Patat et al. 2007, Science 317, 924
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia precursor scenarios
single or double degenerate ?
X-ray
(Chandra)
Roelofs etal 2008 astro-ph/0802-2097
2003
optical
(HST)
2004
optical
(SWIFT)
X-ray
X-ray luminosity consistent with
typical super-soft source
 single degenerate, accreting
progenitor model is favored
optical
offset: 1.18±0.27”
SN2007on
Voss & Nelemans 2008 Nature 451, 802
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia progenitor population
Adopting SFR as in Hopkins & Beacon 2006
Botticella et al. 2008 A&A 479, 49
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN Ia progenitor population
Adopting SFR as in Hopkins & Beacon 2006
Botticella et al. 2008 A&A 479, 49
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SNe and GRBs
Long GRBs are linked to highly energetic SN Ic
SN 1998bw / GRB98042
SN 2003dh / GRB030329
SN 2003lw / GRB031203 1998bw
1994I
1998bw
Galama et al 1998 Nature 395, 762
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SNe and GRBs
There are high energy SN Ic without GRB
SN1997ef
SN 2002ap
SN 2003jd
SN 2004aw
Mazzali et al 2005 Science 308, 1284
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SNe and GRBs
Some long GRB do not show a SN
GRB010921
GRB060614
No SN brighter than
magV = -12.6
Gal-Yam et al 2006
Nature 44,1053
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SNe and GRBs
GRB/XRF can be associated to normal SN Ib/c
SN 2006jc / XRF060218
SN 2008D / XRF080109
20 dec 2001
16 oct 2004
A WR which had a LBV-like
outburst 2 yr before core collapse
Mazzali
etal
21
sep 2006
52° Congresso SAIt
submitted
20 oct 2006
Pastorello et al 2007 Nature 447, 829
Teramo, 4 - 8 Maggio 2008
SNII: H rich, core collapse
progenitor
M > 8MO
kinetic
energy
~1051 erg
total energy
~1053 erg
remnant
neutron star
After 1987A
ejecta
1 - 30 MO
composition O, Mg, Si, Ne, Ca
age
< 50 Myr
Progenitor radius  early light curve
realization
100%
Explosion energy  56Ni mass
Mass loss history  ejecta mass, CSM
Asymmetries  explosion mechanism
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
From core collapse to
explosion
…….. the mechanism for core collapse supernova explosions remains unknown.
Nonetheless, one-, two-, and three-dimensional simulations performed thus far have
shown that (1) neutrino transport, (2) fluid instabilities, (3)rotation, and (4) magnetic
fields, together with proper treatments of (5) the sub- and super- nuclear density stellar
core equation of state, (6) the neutrino interactions, and (7) gravity will be important.
Mezzacappa, A. (2005) ASP Conference Series, Vol. 342, p.175
One of the outstanding problems in astrophysics is the mechanism of core-collapse
supernova explosions. …..………………………. The potential roles as factors in
explosion of neutrinos, the nuclear equation of state(EOS), exotic physics, general
relativity, dimensionality, instabilities, magnetic fields, and rotation all continue to be
topical.
Burrows et. al. 2006 ApJ 640, 678
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SNII: H rich, core collapse
1 order of mag in
envelope
mass
5 mag
5 mag range at
maximum
Small spread in
nebular phases
MNI=0.07 M
1 order of mag in
progenitor radius
Turatto et al 1990
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
Faint core collapse SNe
.. fallback of material onto the collapsed
remnant of the explosion of a 25-40 M
0.3 > MNi > 0.002M
Pastorello et al 2004 MNRAS 347 ,74
Turatto et al. 1998
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
Faint core collapse SNe
The progenitor of
SN 2005cs
M = 9 ± 3 MSUN
Maund et al. 2005 MNRAS 364, L33
M = 10 ± 3 MSUN
Li et al. 2006 ApJ 641, 1060
M = 6-8 Msun
Eldridge et al 2007 MNRAS 376, 52
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
SN II modelling
92am
98bw
69L
99em
04A
03gd
87A
05ay
97D
99br
05cs
01dc
03Z
Iwamoto etal 2000
Zampieri 2007 AIPC 924, 358
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008
Very massive stars
1. Pair-instability SN, producing 15-20 Msun
of Ni56 (Smith 2007 astro-ph/0710.3431)
2. Massive shell ejection due to
pulsational pair instalibiliy (Woosley et al
2007 Nature 450,390 ApJL 671, 17)
3. High energy SN Ia in a dense shell
(2002ic–like) (Oefk 2007 ApJ 659, 13)
4. Collision of two massive stars in a
dense young cluster (Portegies & van den
Heuvel 2007 Nature 450, 388)
5. Core collapse of a massive star within
a 10 Msun shell ( η Carinae – like)
(Smith & McCray 2007 ApJL 671, 17)
Smith et al. 2008 astro-ph/0804.0042
52° Congresso SAIt
6. Quark nova
astro-ph/0708.1787)
(Leahy and Ouyed 2008
Teramo, 4 - 8 Maggio 2008
What next
o Understanding the physics of SNIa to
support future SNAP-JDEM mission:
detailed observation and modeling of nearby SN Ia
o What dictates the final fate of massive stars:
observing and modeling the UV - optical – nearIR SN SED
o Link SN progenitor to their parent population:
measure the SN rates at high redshift (z>1)
52° Congresso SAIt
Teramo, 4 - 8 Maggio 2008