Talk presented at a workshop on gravitational waves hosted by the Instituto de Cosmologia y Fisica de las Americas (COFI) in San Juan, Puerto Rico

1. Chris&an
D.
O-
TAPIR,
California
Ins&tute
of
Technology
Simula&ng
eXtreme
Space&mes
(SXS)
Collabora&on
Sherman
Fairchild
Founda0on
Simula0on
and
Modeling
of
Gravita0onal
Wave
Sources

2. C.
D.
O-
@
COFI,
2015/12/05
2
Gravita&onal
Wave
Emission
• GWs
(in
GR!)
are
to
lowest-­‐order
quadrupole
waves.
• Emi-ed
by
accelerated
aspherical
bulk
mass-­‐energy
mo&ons.
• “Slow-­‐mo&on”
“weak-­‐field”
quadrupole
approxima&on:
mass
quadrupole
moment
dimensionless
GW
“strain”
(displacement)
G
c4
⇡ 10 49
s2
g 1
cm 1
First
Numerical
Es&mate:
Ijk =
Z
⇢xjxkd3
x
d2
dt2
I ⇠ O(Mv2
) h ⇠
2G
c4D
Mv2
M = 1M
D = 10 kpc
v = 0.1c
h ⇠ 10 19
M ⌘ ”aspherical mass”
(adv.
LIGO:
~4
x
10-­‐24
@
200
Hz)

3. C.
D.
O-
@
COFI,
2015/12/05
3
GW
Emission
• GWs
are
very
weak
and
interact
weakly
with
ma-er.
• No
human-­‐made
sources
(of
detectable
GWs):
M = 1000 kgExample:
~⌦
R = 10 m
⌦ = 100 Hz
D = 100 m
(detector
distance)
h ⇠ 10 37-­‐>
GW
strain
amplitude:
(adv.
LIGO:
~4
x
10-­‐24
@
200
Hz)

4. C.
D.
O-
@
COFI,
2015/12/05
4
GW
Emission
• GWs
are
very
weak
and
interact
weakly
with
ma-er.
• No
human-­‐made
sources.
GW
generator,
TAPIR
group,
Caltech

7. C.
D.
O-
@
COFI,
2015/12/05
7
NASA,
M.
Weiss
Vela
GW
data
stream
+
mock
signal
at
SNR
10
mock
GW
signal
Need
signal
predic&ons
for:
-­‐>
Detec&on
of
weak
signals
(matched
filtering).
-­‐>
Es&ma&on
of
source
parameters
&
physics.
-­‐>
Tests
of
General
Rela&vity.
Why
Simula&on
and
Modeling?

8. 8
Simula0on
vs.
Modeling
of
GWs
NASA,
M.
Weiss
Vela
Simula0on
• From
first
principles.
• Is
self-­‐consistent
and
depends
on
few
free
parameters.
• Makes
as
few
approxima&ons
as
possible.
• Typically
involves
PDEs.
• Extremely
computa&onally
expensive.
Some&mes
prohibi&vely
expensive.
• Yields
reliable
predic&ons
(modulo
systema&cs).
Modeling
• From
phenomenological,
approx.
/
perturba&ve
model.
• Depends
on
many
free
parameters.
• Ohen
tuned
/
calibrated
based
on
simula&ons.
• Typically
involves
ODEs.
• Computa&onally
inexpensive.
• Yields
predic&ons
whose
reliability
must
be
tested
with
simula&ons.
(both
are
needed)
C.
D.
O-
@
COFI,
2015/12/05

9. C.
D.
O-
@
COFI,
2015/12/05
9
GW
Signal
Types,
Simula&on
&
Modeling
NASA,
M.
Weiss
Vela
Coalescence
Signals
(Compact
Binary
Coalescence
[CBC])
(Ohme
2012)
• (Rela&vely)
simple
signal
morphology.
• Can
be
well
modeled
/
simulated;
ideal
for
matched
filtering.
• BH+BH
(BBH),
NS+NS,
NS+BH.
(J.
Blackman)

10. C.
D.
O-
@
COFI,
2015/12/05
10
GW
Signal
Types,
Simula&on
&
Modeling
NASA,
M.
Weiss
Vela
Coalescence
Signals
(Compact
Binary
Coalescence
[CBC])
Bursts
• Complex
signal
morphology.
• Hard
or
impossible
to
model,
difficult
to
simulate.
• Chao&c
signal
components
(e.g.,
due
to
turbulence).
• Matched
filtering
generally
not
applicable.
(O-
2009)
Examples:
Core-­‐collapse
supernovae
Postmerger
NS+NS

11. C.
D.
O-
@
COFI,
2015/12/05
11
GW
Signal
Types,
Simula&on
&
Modeling
NASA,
M.
Weiss
Vela
Coalescence
Signals
(Compact
Binary
Coalescence
[CBC])
Bursts
Con0nuous
Waves
• Well
modeled,
highly
periodic
signals
due
to
small
deforma&ons
of
spinning
NSs.
(A.
Stuver)
(M.
Kramer)

12. C.
D.
O-
@
COFI,
2015/12/05
12
GW
Signal
Types,
Simula&on
&
Modeling
NASA,
M.
Weiss
Vela
Coalescence
Signals
(Compact
Binary
Coalescence
[CBC])
Bursts
Con&nuous
Waves
• Cosmological:
Big
Bang,
infla&on
• Astrophysical:
superposi&on
of
cosmol.
popula&on
of
CBC/burst
events.
• Stochas&c
–
no
detailed
h(t)
predic&on
possible.
Stochas0c
Backgrounds

13. C.
D.
O-
@
COFI,
2015/12/05
13
Example
1:
Coalescing
BH+BH
Pairs
NASA,
M.
Weiss
Vela
Parameter
space
(J.
Blackman)
The Binary Black Hole Parameter Space
Black hole masses m1, m2
Spin vectors ~1 and ~2, k~i k = k~Si k/m2
i < 1
Total mass M = m1 + m2 can be scaled out, leaving 7 parameters
A moderately dense covering of the parameter space would require
⇠ 107 waveforms!
Pure
gravity!
Gµ⌫
= 0
(K.
Thorne)
<-­‐
this
is
why
modeling
is
needed!

14. C.
D.
O-
@
COFI,
2015/12/05
14
Binary
Black
Hole
Coalescence
NASA,
M.
Weiss
Vela
Ohme
2012
Strong
field
limit
• Modeling:
– Post-­‐Newtonian
(PN)
approximants
(expansion
in
v/c).
Only
inspiral.
Fails
in
strong-­‐field
regime.
– Effec&ve-­‐one-­‐body
(EOB)
and
“Phenom”-­‐type
PN
models:
Fits
of
PN
inspiral,
merger,
ringdown.
Calibrated
on
NR
simula&ons.
– NR
“surrogate
models”
via
reduced-­‐order
modeling.
• Simula&on:
Numerical
Rela&vity
−
direct
integra&on
of
field
eqns.

15. C.
D.
O-
@
COFI,
2015/12/05
15
Binary
Black
Hole
Coalescence
NASA,
M.
Weiss
Vela
Buonanno
&
Sathyaprakash
14
Validity
of
methods
Extreme
Mass
Ra&o
(EMRI)
mass
ra&o
strength
of
rela&vis&c
dynamics/
gravity.
c2
v2
⇠

16. C.
D.
O-
@
COFI,
2015/12/05
16
Numerical
Rela&vity
Simula&ons
NASA,
M.
Weiss
Vela
Proceedings
of
the
GR1
Conference
on
the
role
of
gravita&on
in
physics
University
of
North
Carolina,
Chapel
Hill
[January
18-­‐23,
1957]
(via
P.
Laguna
&
D.
Shoemaker)
(K.
Thorne)
-­‐>
It
took
un&l
2005
(Pretorius,
Campanelli+,
Baker+)
to
simulate
first
BBH
merger!

17. Figure:
C.
Reisswig
Folia0on
of
space0me
3-­‐hypersurface
• 12
first-­‐order
hyperbolic
evolu&on
equa&ons.
• 4
ellip&c
constraint
equa&ons
• 4
coordinate
gauge
degrees
of
freedom:
α,
βi.
C.
D.
O-
@
COFI,
2015/12/05
17
Numerical
Rela0vity

18. C.
D.
O-
@
COFI,
2015/12/05
18
Numerical
Rela0vity
Key
issues
• Ini&al
condi&ons
must
sa&sfy
Einstein
equa&ons.
• No
unique
way
to
formulate
evolu&on
equa&ons.
• Gauge
freedom
–
how
choose
gauge
condi&ons?
• Need
combina&on
of
evolu&on
equa&ons
+
gauges
that
yield
to
numerically
stable
simula&ons.
BSSN
Formula0on
Generalized
Harmonic
Formula0on
Nakamura+87,
Shibata
&
Nakamura
95,
Baumgarte
&
Shapiro
99
Friedrich
85,
Pretorius
05,
Lindblom+
06
• Conformal-­‐traceless
reformula&on
of
Arnowi--­‐Deser-­‐Misner
59,
York
79.
• Addi&onal
evolu&on
equa&ons,
condi&onally
strongly
hyperbolic.
• Sensi&ve
to
gauge
choice;
good
gauges
known.
• Most
widely
used
evolu&on
system
today.
• Choice
of
coordinates
so
that
evolu&on
equa&ons
wave-­‐equa&on
like.
Symmetric
hyperbolic.
• Sensi&ve
to
gauge
choices,
horizon
boundary
condi&ons.
• Used
primarily
by
Caltech/Cornell
SXS
code
SpEC.

19. C.
D.
O-
@
COFI,
2015/12/05
19
• Spectral
Einstein
Code:
SpEC
Caltech-­‐Cornell-­‐CITA-­‐Fullerton
Simula&ng
eXtreme
Space&mes
Collabora&on
(SXS)
• Generalized
harmonic
formula&on.
• Explicit
mul&-­‐domain,
mul&-­‐frame
pseudo-­‐spectral
methods.
C++.
• Severely
scaling
limited
>
48
cores.
1
simula&on
with
40
orbits:
3-­‐6
months
on
48
cores.
• Proprietary
(closed
source).
More
info
on
h-p://www.black-­‐holes.org
Example
Computa0onal
Approach:
SpEC

20. C.
D.
O-
@
COFI,
2015/12/05
20
Pfeiffer/Scheel

21. C.
D.
O-
@
COFI,
2015/12/05
21
BBH
&
Advanced
LIGO/Virgo
NASA,
M.
Weiss
• BBH
Source
popula&on
&
parameters
unknown!
• Present
EOB/Phenom
models
calibrated
for
moderate
(mostly
aligned)
spins,
mass
ra&os
m1/m2
~
1
–
1:10.
• NR
simula&ons
needed
for
rest
of
parameter
space
(high
spin,
precession).
(at
40
Mpc)
(at
1
Gpc)
(at
1
Gpc)
(at
1
Gpc)

22. C.
D.
O-
@
COFI,
2015/12/05
22
Complete
Waveforms:
Problems
NASA,
M.
Weiss
Vela
• 7D
parameter
space
–
at
least
107
simula&ons
needed.
• Many
cycles
in
sensi&vity
band:
N ⇠
4
2⇡
⇥ 104
✓
M
M
◆ 5/3
O(100)
for
5+5
M⦿
-­‐>
Impossible
with
numerical
rela&vity
simula&ons!

23. C.
D.
O-
@
COFI,
2015/12/05
23
Complete
Waveforms:
Solu&ons
NASA,
M.
Weiss
Vela
• Many
cycles
in
sensi&vity
band:
N ⇠
4
2⇡
⇥ 104
✓
M
M
◆ 5/3
(~130
for
5+5
M⦿)
Solu&on:
“Hybridiza0on”
Further
problem:
#
of
required
NR
cycles
unknown;
dependent
on
system
parameters.

24. C.
D.
O-
@
COFI,
2015/12/05
24
Complete
Waveforms:
Solu&ons
NASA,
M.
Weiss
Vela
Solu&on:
“Surrogate
Model”
via
Reduced-­‐Order
Modeling
• 7D
parameter
space
–
at
least
107
simula&ons
needed.
(1)
Intelligently
&
sparsely
sample
parameter
space
with
O(1,000)
numerical
rela&vity
simula&ons.
(2)
Interpolate
between
waveforms
to
obtain
waveform
for
any
set
of
BBH
parameters.
Basic
Idea:
Goal:
Build
model
that
is
as
good
as
NR
and
can
be
a
subs&tute
for
NR
simula&ons
(surrogate).

25. Have N reduced basis
waveforms (blue lines)
Fit data at N empirical
time nodes (red lines)
using known data (black
dots)
Evaluate fits at arbitrary
parameter(s) (cyan
dots)
Use empirical interpolant
to uniquely determine
new data (cyan line)
C.
D.
O-
@
COFI,
2015/12/05
25
Numerical
Rela&vity
Surrogate
Models
Vela
(by
Jonathan
Blackman)

26. C.
D.
O-
@
COFI,
2015/12/05
26
Numerical
Rela&vity
Surrogate
Models
NASA,
M.
Weiss
Vela
(by
Jonathan
Blackman,
Blackman+15)
1D
surrogate
model
(mass
ra&o).
Work
on
mul&-­‐D
surrogate
models
in
progress.

27. C.
D.
O-
@
COFI,
2015/12/05
27
Example
2:
NSNS
and
BHNS
Mergers
NASA,
M.
Weiss
Vela
• Harder:
must
simulate
also
ma-er
(and
magne&c
fields)
-­‐>
(magneto)-­‐hydrodynamics,
neutrinos,
nuclear
EOS.
• But:
lower
mass
-­‐>
PN
approx.
valid
for
much/most(NSNS)
of
inspiral.
M1
~
M2
~
1.4
MSun
-­‐>
galac&c
NSNS
binaries!
MBH
~
7-­‐10
x
MNS
(Belczynski+’10)
(but
no
BHNS
systems
known)
credit:
D.
Tsang

28. C.
D.
O-
@
COFI,
2015/12/05
28
NSNS
in
the
Advanced
Detector
Band
NASA,
M.
Weiss
Vela
• Poten&al
to
constrain
nuclear
equa&on
of
state.

29. Mul0-­‐Physics,
Mul0-­‐Messenger
Astrophysics
29
C.
D.
O-
@
YKIS
2013,
2013/06/07
Nuclear
Equa0on
of
State
(EOS)
Neutrinos/Neutrino
Interac0ons
Nuclear
Reac0ons
&
Opaci0es
Crust
Physics
&
Superfluidity
(SF)
EOS
Crust/SF
hot
EOS
hot
EOS
Neutrinos
Neutrinos
Neutrinos
hot
EOS
Neutrinos
Nuclear
Nuclear
Nuclear
hot
EOS
EM
aherglow/
counterpart

30. Gamma-­‐Ray
Bursts
C.
D.
O-
@
COFI,
2015/12/05
30
BATSE
LGRBs
SGRBs
• Two
general
groups
of
GRBs:
Long
and
Short
• Favored
model:
Beamed
Ultrarela&vis&c
ou}low
emi~ng
γ-­‐rays.
[Reviews:
e.g.
Woosley
&
Bloom
‘06,
Piran
‘05,
Meszaros
’05]
NS-­‐NS
/
NS-­‐BH
merger
Massive
H/He-­‐poor
Star
SGRB
LGRB
Simplis0c
Engine
Picture:
Energy
sources:
Gravita&onal
energy
(accre&on)
Black
Hole/NS
spin
energy.
Disk
Mass:
∼0.1
MSun
Disk
Mass:
∼1
MSun
Media0ng
Processes:
Neutrino
Pair
Annihila&on
Magnetohydrodynamics

31. C.
D.
O-
@
COFI,
2015/12/05
31
NSNS
Simula&ons:
Outcomes
NASA,
M.
Weiss
Vela
Sensi&vity
to
system
mass,
mass
ra&o,
and
nuclear
EOS.

32. C.
D.
O-
@
HIPACC
Summer
School
2014,
2014/07/23
32
BHNS
Merger
Scenario
Kyohei
Kawaguchi

33. C.
D.
O-
@
COFI,
2015/12/05
33
NSNS/NSBH
Modeling
and
Simula&on
NASA,
M.
Weiss
Vela
• NSNS:
PN
approxima&on
valid
through
inspiral,
mul&-­‐physics
NR+GR(M)HD
simula&on
for
merger/postmerger
evolu&on.
• BHNS:
PN
approxima&on
valid
in
inspiral
if
mass
ra&o
MBH/MNS
small
and
BH
spin
small.
But:
most
likely
BH
spin
large,
MBH/MNS
>
~7:1.
-­‐>
need
long
NR+GR(M)HD
BHNS
inspiral
simula&ons.
credit:
D.
Tsang

34. C.
D.
O-
@
COFI,
2015/12/05
34
Example
3:
Core-­‐Collapse
Supernovae
NASA,
M.
Weiss
Vela
• Explosions
of
massive
stars:
Gravity
bombs.

35. C.
D.
O-
@
COFI,
2015/12/05
35
©
Anglo-­‐Australian
Observatory
Core-­‐Collapse
Supernovae:
Supernova
1987A
Large
Magellanic
Cloud
Progenitor:
BSG
Sanduleak
-­‐69°
220a,
≈18
MSUN
Explosions
of
Massive
Stars
8M . M . 130M

36. Reminder:
Core
Collapse
Basics
C.
D.
O-
@
COFI,
2015/12/05
36
Nuclear
equa&on
of
state
(EOS)
s&ffens
at
nuclear
density.
Inner
core
(~0.5
MSun)
-­‐>
protoneutron
star
core.
Shock
wave
formed.
Outer
core
accretes
onto
shock
&
protoneutron
star
with
O(1)
M⦿/s.
-­‐>
Shock
stalls
at
~100
km,
must
be
“revived”
to
drive
explosion.
Reviews:
Bethe’90
Janka+’12

37. Core-­‐Collapse
Supernova
Energe&cs
C.
D.
O-
@
COFI,
2015/12/05
37
• Collapse
to
a
neutron
star:
∼3
x
1053
erg
=
300
[B]ethe
gravita0onal
energy
(≈0.15
MSunc2).
-­‐>
Any
explosion
mechanism
must
tap
this
reservoir.
• ∼1051
erg
=
1
B
kine&c
and
internal
energy
of
the
ejecta.
(Extreme
cases:
10
B;
“hypernova”)
• 99%
of
the
energy
is
radiated
in
neutrinos
on
O(10)s
-­‐>
Strong
evidence
from
SN
1987A
neutrino
observa&ons.

38. C.
D.
O-
@
COFI,
2015/12/05
38
Example
3:
Core-­‐Collapse
Supernovae
NASA,
M.
Weiss
Vela
• Explosions
of
massive
stars:
Gravity
bombs.
• Mul&-­‐dimensional,
mul&-­‐physics,
mul0-­‐scale
problem.
• What
is
the
detailed
explosion
mechanism?
• Sources
of
GW
bursts
-­‐>
GWs
carry
informa&on
on
mul&-­‐D
dynamics
and
explosion
mechanism
(O-
09).
• Mul&-­‐Messenger
Astronomy
-­‐>
neutrinos,
GWs,
photons!

39. C.
D.
O-
@
COFI,
2015/12/05
39
Magneto-­‐Hydrodynamics
Nuclear
and
Neutrino
Physics
General
Rela&vity
Boltzmann
Transport
Theory
Dynamics
of
the
stellar
fluid.
Nuclear
EOS,
nuclear
reac&ons
&
ν
interac&ons.
Gravity
Neutrino
transport.
Fully
coupled!
• Addi&onal
Complica&on:
Core-­‐Collapse
Supernovae
are
3D
– Rota&on,
fluid
instabili0es,
magne0c
fields,
mul&-­‐D
stellar
structure
from
convec&ve
burning,
etc.
• Full
problem:
3D
space,
3D
momentum
space
+
&me
Detailed
CCSN
Simula0ons:
Ingredients

40. The
3D
Fron0er
–
Petascale
Compu0ng!
C.
D.
O-
@
COFI,
2015/12/05
40
• Modeling:
only
for
photons
(light
curve,
spectra).
• Simula0on
required
for
everything
else.
• Some
early
work:
Fryer
&
Warren
02,
04
• Loads
of
new
work
since
~2010:
Fernandez
10,
Nordhaus+10,
Takiwaki+11,13,
Burrows+12,
Murphy+13,
Dolence+13,
Hanke+12,13,
Kuroda+12,
O-+13,
Couch
13,
Takiwaki+13,
Couch
&
O-
13,
15,
Abdikamalov+15,
Couch
&
O’Connor
14,
Lentz+15,
Melson+15ab,
Cardall&Budiardja
15,
Radice+15,
Summa+15
O-+2013

41. 41
O-+2013
Caltech,
full
GR,
parameterized
neutrino
hea&ng

42. Gravita0onal-­‐Waves
from
Core-­‐Collapse
Supernovae
42
Reviews:
O-
09,
Kotake
11,
Fryer
&
New
11
Need:
accelerated
aspherical
(quadrupole)
mass-­‐energy
mo&ons
Candidate
Emission
Processes:
v Turbulent
convec&on
&
shock
instability
(SASI)
v Rota&ng
collapse
&
bounce
v 3D
rota&onal
instabili&es
v Aspherical
mass-­‐energy
ou}lows:
-­‐>
aspherical
neutrino
emission
-­‐>
aspherical
explosion
3
-150 -100 -50 0 50 100 150
x [km]
-150
-100
-50
0
50
100
150
z[km]
t = 10.00 ms
-30 -20 -10 0 10 20 30
x [km]
-30
-20
-10
0
10
20
30
z[km]
t = 68.88 ms
-30 -20 -10 0 10 20 30
x [km]
-30
-20
-10
0
10
20
30
z[km]
t = 69.39 ms
-30 -20 -10 0 10 20 30
x [km]
-30
-20
-10
0
10
20
30
z[km]
t = 84.00 ms
108 1010 1012 1014
log
108 1010 1012 1014
log
108 1010 1012 1014
log
109 1010 1011
log
FIG. 3: Snapshots of the meridional density distribution with
superposed velocity vectors in model u75rot1 taken at various
0 20 40 60 80 100 120 140
t tbounce [ms]
1
2
3
f[kHz]
u75rot2
3 2 1 0 1 2 3
log |D˜h+,e|2
400
200
0
200
Dh+,e[cm]
DhCCE
+,e u75rot1
DhCCE
+,e u75rot1.5
DhCCE
+,e u75rot2
1.6 0.8 0.0 0.8 1.6
t tBH [ms]
400
200
0
200
FIG. 4: Top: GW signals h+,e emitted by the rotating mod-
els as seen by an equatorial observer and rescaled by distance
C.
D.
O-
@
ERAU,
2015/11/30
GW
emission
weak
–
detectable
only
for
galac&c
CCSN

43. GWs
from
Convec0on
&
Standing
Accre0on
Shock
Instability
43
Recent
work:
Murphy+09,
Kotake+09,
11,
Yakunin+10,
E.
Müller+12,
B.Müller+13
OTT, & BURROWS Vol. 707
he
es
7)
es,
e-
ng
m
8)
We
Figure 2. Sample of GW strain (h+) times the distance, D, vs. time after
Murphy+09
C.
D.
O-
@
ERAU,
2015/11/30
GW
burst!
Murphy+09

44. Time-­‐Frequency
Analysis
of
GWs
44
Murphy,
O-,
Burrows
09,
see
also
B.
Müller+13
fp ⇠
!BV
2⇡
Peak
emission
traces
buoyancy
frequency
at
proto-­‐NS
edge.
(buoyancy
frequency)
C.
D.
O-
@
ERAU,
2015/11/30

45. GWs
from
Rota0ng
Collapse
&
Bounce
C.
D.
O-
@
ERAU,
2015/11/30
45
Recent
work:
Dimmelmeier+08,
Scheidegger+10,
O-+12,
Abdikamalov+14
• Axisymmetric:
ONLY
h+
• Simplest
GW
emission
process:
Rota0on
+
mass
of
inner
core
+
gravity
+
s0ffening
of
nuclear
EOS
• Strong
signals
for
rapid
rota&on
(-­‐>
millisecond
proto-­‐NS).

46. C.
D.
O-
@
ERAU,
2015/11/30
46
Simple
signal
features:
Axisymmetric
rota&ng
collapse
Permits
es&ma&on
of
core
angular
momentum.
Can
(almost)
be
used
for
matched
filtering!
GWs
from
Rota0ng
Collapse
&
Bounce
Recent
work:
Dimmelmeier+08,
Scheidegger+10,
O-+12,
Abdikamalov+14

47. C.
D.
O-
@
ERAU,
2015/11/30
47
3D
Rota&onal
Instabili&es
Simula&on:
C.
D.
O-,
Visualiza&on:
R.
Kaehler

48. C.
D.
O-
@
GW2010,
UMN,
2010/10/15
48
Polar
Observer
+
Polar
Observer
x
Equatorial
Observer
x
Equatorial
Observer
+
O-+07

49. GWs
from
Asymmetric
Neutrino
Emission
C.
D.
O-
@
CASS
UCSD
2009/11/18
49
[Epstein
1978,
Burrows
&
Hayes
1996,
Janka
&
Müller
1997,
Müller
et
al.
2004,
Dessart
et
al.
2006,
O-
2009]
• Any
accelerated
mass-­‐energy
quadrupole
will
emit
GWs.
Asymmetric
neutrino
radia&on:
Asymmetric
neutrino
emission
in
core-­‐collapse
SNe:
• Convec0on:
small-­‐scale
varia&ons.
• Rapid
rota0on:
large-­‐scale
asymmetry.
• Large-­‐scale
asymmetries:
large-­‐scale
asymmetry.
[O-
et
al.
2008]
GW
“Memory”
[Dessart
et
al.
2006,
O-
2008
Accre&on-­‐Induced
Collapse
Large
h,
low
frequency

50. The
Einstein
Toolkit
Project
C.
D.
O-
@
COFI,
2015/12/05
50
Mösta+14
Löffler+12
h-p://einsteintoolkit.org

51. The
Einstein
Toolkit
C.
D.
O-
@
COFI,
2015/12/05
51
Mösta+14
Löffler+12
• Collec&on
of
open-­‐source
sohware
components
for
the
simula&on
and
analysis
of
general-­‐rela&vis&c
astrophysical
systems.
h-p://einsteintoolkit.org

52. The
Einstein
Toolkit
C.
D.
O-
@
COFI,
2015/12/05
52
Mösta+14
Löffler+12
• Collec&on
of
open-­‐source
sohware
components
for
the
simula&on
and
analysis
of
general-­‐rela&vis&c
astrophysical
systems.
• Supported
by
NSF
via
collabora&ve
grant
to
Georgia
Tech,
LSU,
RIT,
and
Caltech.
• ~110
users,
53
groups;
~10
ac&ve
maintainers.
• Goals:
h-p://einsteintoolkit.org
- Reproducibility.
- Build
a
community
codebase
for
numerical
rela&vity
and
computa&onal
rela&vis&c
astrophysics.
- Enable
new
science
by
lowering
technological
hurdles
for
researchers
with
new
ideas.
Enable
code
verifica&on/valida&on,
physics
benchmarking,
regression
tes&ng.
- Make
it
easy
for
users
to
take
advantage
of
new
technologies.
- Provide
cyberinfrastructure
tools
for
code
and
data
management.

53. The
Einstein
Toolkit
C.
D.
O-
@
COFI,
2015/12/05
53
Mösta+14
Löffler+12
• Cactus
(framework),
Carpet
(adap&ve
mesh
refinement)
• GRHydro
–
GRMHD
solver
• McLachlan
–
BSSN/Z4c
space&me
solver
(code
auto-­‐generated
based
on
Mathema&ca
script,
GPU-­‐enabled)
• Ini&al
data
solvers
/
importers
• Analysis
tools
(wave
extrac&on,
horizon
finders,
etc.)
• Visualiza&on
via
VisIt
(h-p://visit.llnl.gov)
Available
Components:
• Regular
releases
of
stable
code
versions.
Most
recent:
“Somerville”
release,
November
2015
• Support
via
mailing
list
and
weekly
open
conference
calls.
• Working
examples
for
BH
mergers,
NS
mergers,
isolated
NSs,
rota&ng,
magne&zed
core
collapse.

54. The
Dawn
of
Gravita0onal
Wave
Astronomy
Stay
Tuned…
LIGO-­‐G1501322v1
D.
Reitze
Betelgeuse,
D~200
pc