Compact Binary Mergers
as Sources of r-process
Nucleosynthesis
Tsvi PiranThe Hebrew University
Kenta Hotokezaka, Ehud Nakar, Paz Beniamini,David Wanderman, Reetanjali Moharana

Hirschegg Jan 2017
GRB ; TReX

1.

5.

Astronomical evidence for rate sources
i. 244Pu
ii. Binary neutron star kicks and all thatiii. Dwarf Galaxies
Conclusion - Low rate high yield - SNe👎Merger rates:
i. Short GRBs
ii. Binary NS
Conclusion mergers - Mergers 👍The Li-Paczynski Macronova (kilonova)
Macronove 130603b/060614/050709
If correct sGRBs == Mergers 👍Evidence for “stuff” around SGRBs 👍6.

Galactic Chemical Evolution 👍

7.

* The cocoon’s macronova - the strongest EM
counterpart?

2.

3.
4.

Some References
Hotokezaka TP & Paul Nature Phys 2015- 244Pu
TP & Shaviv PRL2005; Dall’Osso, TP & Shaviv MNRAS,
2013, Beniamini & TP MNRAS 2015 - NS kicks
Beniamini, Hotokezaka & TP 2016a,b - Dwarf Galaxies
Wanderman & TP, MNRAS 2015 - sGRB rate
Yang + Nature comm. 2015; Jin + Nature comm. 2016 macronvoa candidates
Moharana, + in prep 2017 - mass ejection evidence
Hotokezaka & TP in prep 2017 - Chemical evolution
Nakar & TP ApJ 2017; Gottelib, Nakar & TP in prep 2017
- Cocoon signature
Nakar & TP Nature 2011; Hotokezaka & TP MNRAS 2014;
Horesh + ApJ 2016 Hotokezaka + ApJ 2016 - Radio FlareR-Process
10000

LIGO/Virgo limit

R(z=0) [Myr-1]

R-e
lem

ent

1000

mass
(A>90)

Macronova
candidate

Galactic NS2

100
10

Short GRBs

1
Advanced (5yr)

0.1
0.00010.001

0.01
Mej [Msun]

0.11

R-Process
10000

LIGO/Virgo limit

R(z=0) [Myr-1]

R-element

1000mass(A>90)

Macronova
candidate

Galactic NS2100
10

Short GRBs

1
Advanced (5yr)

0.1
0.00010.001

0.01
Mej [Msun]

0.11

R-Process
10000

LIGO/Virgo limit

R(z=0) [Myr-1]

R-element

1000

mass(A>90)

Macronova
candidate

Galactic NS2100
10

Short GRBs

1
Advanced (5yr)

0.1
0.00010.001

0.01
Mej [Msun]

0.1

1

Can we break the yield - rate degeneracy?
Hotokezaka, TP Paul, Nature Pays 2015

R-Process
10000

LIGO/Virgo limit

R(z=0) [Myr-1]

R-element

1000

mass(A>90)

Macronova
candidate

Galactic NS2

100
10Short GRBs

1
Advanced (5yr)

0.1
0.00010.001

0.01
Mej [Msun]

0.11

Can we break the yield - rate degeneracy?
Hotokezaka, TP Paul, Nature Pays 2015

Radioactive Elements
Rare Eventst

Frequent eventst

Tissot + 16t

244Pu (half life 81Myr)

The early
solar system
Current
deposition
rate

Wallner + 14

244High
Pu at the earlysolar system =>244Pu Radioactive decay time ~ 100 Myear

A nevent near the early solar system
Mixing time < 150 Myr
Large fluctuations possible => Event rateis low
Lack of Cu => 10 Myr < Mixing timeRare and “massive” events

Hotokezaka, TP & Paul, Nature Pays, 2015

A remark about binary neutron stars
TP & Shaviv 2005; Dall’Osso, TP & Shaviv 2013,Beniamini & TP 2015

✴Most observed Galactic
binary neutron stars havealmost circular orbits and alow proper motion➡Very low mass ejection (<0.1Msun for J0737-3039B)➡NOT formed in a regular SNe➡Most won’t be ejected from a
Dwarf Galaxyr-process material in Dwarf Galaxies(Beniamini, Hotokezaka & TP 16a,b)

The most enriched Galactic low metallicity star
(Macias & Ramirez Ruiz 2016)

Rare & Large Yield
EventsRegular SNe?

Mergers?
Rare Sne?

Cnclusions so far-1Rate ~20-30 Myr✴
✴Yield ~0.01-0.1 msun
➡low rate high yield events➡SNe👎➡Mergers? or Rare SNe?

The Rate of short GRBs

(Wanderman & TP 2015)
Current observed rate
~ 5 Gpc-3 yr-1 ~0.5 Myr-1
Earlier rate is larger
Uncertainties
Short delay mergers (needhigh redshift sGRBs) canbe ~20 Myr!!!
Lowest energy (rate can behigher)
Beaming factorx10-70(Very uncertain)

Wanderman

Galactic rate from binary pulsars 21-14+28 My-1 (Kim + 15)

With estimates of the merger rate

Macronova*(Li & Paczynski 1997)• Radioactive decay of theneutron rich matter.

• Eradioactive2≈ 0.001 Mc ≈50
10 erg• A weak short Supernova
like event.

*Also called Kilonova

Bohdan Paczynski

Macronova*(Li & Paczynski 1997)• Radioactive decay of theneutron rich matter.

• Eradioactive2≈ 0.001 Mc ≈5010 erg• A weak short Supernova
like event.

*Also called Kilonova Hektanova

Bohdan Paczynski

Macronova*(Li & Paczynski 1997)• Radioactive decay of theneutron rich matter.

• EradioactiveBohdan Paczynski

2≈ 0.001 Mc ≈5010 erg• A weak short Supernova
like event.

*Also called Kilonova Hektanova Decanova

Lanthanides dominate the opacity(Kassen & Barnes 13, Tanaka & Hotokezaka 13) )2
κ= 10cm /gm

tmax ∝κ1/2=> l o n g e r
Lmax ∝κ-0.65 => weakerT ∝ κ-0.4=> redderLanthanides dominate the opacity(Kassen & Barnes 13, Tanaka & Hotokezaka 13) )2
κ= 10cm /gm

tmax ∝κ1/2=> l o n g e r
Lmax ∝κ-0.65 => weakerT ∝ κ-0.4=> redderLanthanides dominate the opacity(Kassen & Barnes 13, Tanaka & Hotokezaka 13) )2
κ= 10cm /gm

tmax ∝κ1/2=> l o n g e r
Lmax ∝κ-0.65 => weakerT ∝ κ-0.4=> redder
1days

10

Lanthanides dominate the opacity(Kassen & Barnes 13, Tanaka & Hotokezaka 13) )2
κ= 10cm /gm

tmax ∝κ1/2=> l o n g e r
Lmax ∝κ-0.65 => weakerT ∝ κ-0.4=> redder

1041

1040

1days

10

Lanthanides dominate the opacity(Kassen & Barnes 13, Tanaka & Hotokezaka 13) )2
κ= 10cm /gm

tmax ∝κ1/2=> l o n g e rLmax ∝κ-0.65 => weakerT ∝ κ-0.4=> redder

1041

1040

uv or optical -> IR

1days

10

GRB130603B @ 9 days AB(6.6 days at the source frame)V

HST image (Tanvir + 13)

nIRSwiftMacronova?

Tanvir + 13, Berger + 13

If correct
Confirmaiton of the GRB neutronstar merger model (Eichler, Livio,
TP & Schramm 1989).
Confirmation of the Li-Paczynski
Macronova (Li-Paczynski 1997).
Confirmation that compact binary
mergers are the source of heavy(A>130) r-process material: Gold,Silver, Platinum, Plotonium,Uranium etc…(Lattimer &Schramm, 75).

GRB 060614

Yang et al., 2015

Need M≃0.1 msun *=> BH-NS ?
* mass estimate may
increase (efficiency)
BUT may decrease if
additional energy
source beyond
radioactivity!

GRB 050709
3!"#$ %&'()*+ ,-.+/!"#!!

!"#$ %$#&'()*"!"!#'"#'"!
!"&!"%!"$!"#!"!

Need M≃0.05msun *=> BH-NS ?
#()*+,-.,/01 2'!!"345'!

!$!%:')#;<=>!&!')!

"$)(*+,- .+/0- 123.4 5678.9!("( #(optical observations of sGRB 050709. The R-band emission (green dashed line) decreases as t 1.63±0.16 , consistentand data. On the other hand the I-band (VLT I-band data as well as the first two HST F814W-band data
se much slower as of t 1.12±0.09 (red dash-dotted line). This is strongly suggesting an additional optical emission
merging at t
2.5 days that is characterized by a low-luminosity and a soft spectrum. In the insert we show
he afterglow of sGRB 050709 measured by VLT on July 12, 2005 compared with a possible Iron line-like spectral
pted from Kasen et al. [? ]. For illustration, we present a simulated I-band macronova light curve [? ] for theJin et al., 2016

Are Macronova Frequent?
There are 3 (6) possible (nearby) historicalcandidates with a good enough data
In 3/3 (3/6) there are possible
Macronovae

Macronova Mass estimates
0.02-0.1 msun * mass estimate may increase(efficiency) BUT may decrease if additionalenergy source beyond radioactivity! (seeKisaka, Nakar & Ioka 2016 for an additionalenergy source)

10000

LIGO/Virgo limitR-eR(z=0) [Myr-1]

lem1000

entmass

Macronova
candidate(A>90)

Galactic NS2

100
10

Short GRBs

1
Advanced (5yr)

0.1
0.00010.001

0.01
Mej [Msun]

0.1

1

The Secret Signatures of GRB cocoons

Nakar & TP, ApJ 17

The Jet drills a hole in the staror in the surrounding ejecta

Jet breakout(Bromberg Nakar, TP, Sari 11 ApJ 2011)

LGRBs
sGRBstb ≈ 0.37 L θ−1/3 4/3o49
102/3
9R M

1/30.1s

The engine must be active until
the jet’s head breaks out!*Jet breakout(Bromberg Nakar, TP, Sari 11 ApJ 2011)

sGRBstb ≈ 0.37 L θ−1/3 4/3o49
102/3
9R M

1/3
0.1s

The engine must be active until
the jet’s head breaks out!*

3D simulation

4Msun, R*=4x1010cm. Lj =1051erg/s, θ=8ο Using Pluto with highresolution ΔR=107cm. Credit: Ore Gottlieb3D simulation

4Msun, R*=4x1010cm. Lj =1051erg/s, θ=8ο Using Pluto with highresolution ΔR=107cm. Credit: Ore Gottlieb2D simulation

SGRB with a wind velocity of 0.2c. Credit: Ore Gottlieb2D simulation

SGRB with a wind velocity of 0.2c. Credit: Ore GottliebA prediction jet
penetration model
Observed
duration

T90 = Te-TB
Enginetime

Break outtime

T90

A prediction jet
penetration modeldN(T90)/dt

Observed
duration

T90 = Te-TB
Enginetime

Break outtime

T90

A prediction jet
penetration modeldN(T90)/dt

Observed
duration

T90 = Te-TBEngine
time

Break out
time

TB

T90

The Collapsar Plateau(Bromberg Nakar, TP & Sari, 2011)
dN/dT90

T90

The Collapsar Plateau(Bromberg Nakar, TP & Sari, 2011)
dN/dT90

T90

A direct observational proof of the Collapsar
model.

The short GRB Plateau(Moharana, Hotokezaka, Nakar & TP in prep2017)
dN/dT90

Batse
Swift (x/5)
Fermi (x/100)

1000(dN/dT90)

100

101

0.1
0.1

1
T90[sec]

T90

The short GRB Plateau(Moharana, Hotokezaka, Nakar & TP in prep2017)
dN/dT90

Batse
Swift (x/5)
Fermi (x/100)

1000(dN/dT90)

100

101

0.1
0.1

1T90[sec]

T90

A direct observational evidence for~0.05 msun ejecta around sGRB

Chemical Evolution(Hotokezaka & TP 2017)
Galactic low metallicity stars
Argast + 2004 result ruling mergers is wrong!
Unfortunately, they neglected turbulent androtational mixing. There is good evidence forsuch mixing over a time scale of 20-100 Myr(from radioactive elements).
The minimal time delay of a binary mergers ishighly uncertain.

The late time evolution puzzle?
(Hotokezaka & TP 2017)

Resolved for a Galactic SFR(Hotokezaka & TP 2017)

Short GRBs Cocoons

From Hotokezaka & TP 2015

Nakar & TP 2017

SGRB cocoon signatures
Rel. Cocoon cooling+=>

Rel. Cocoon Afterglow,scaling from the regular SGRB afterglow
This is a wide angle signal 0.5 rad is stronger
than typical SGRB orphan afterglow

Macronova cocoon signature

Heating due to radioactive decay

Blue signal at around 0.5-1 day! Brighter orcomparable to the classical Macronova

Summary
Cocoons are the forgotten
cousins in the GRB story. They
carry a comparable amount ofenergy to the GRB and arewider than the GRBs.
Short GRBs have their own
cocoons whose signatures might
be the best EM counterpart toThe radio - flare (Nakar & Piran 2011)
Testing the Macronova interpretation
A long lasting radio flaredue to the interaction of
the ejecta withsurrounding matter may
follow the macronova.

The radio - flare (Nakar & Piran 2011)
Testing the Macronova interpretation
A long lasting radio flaredue to the interaction of
the ejecta withsurrounding matter may
follow the macronova.

The radio - flare (Nakar & Piran 2011)
Testing the Macronova interpretation
A long lasting radio flaredue to the interaction of
the ejecta withsurrounding matter may
follow the macronova.

The radio - flare (Nakar & Piran 2011)
Testing the Macronova interpretation
A long lasting radio flaredue to the interaction of
the ejecta withsurrounding matter may
follow the macronova.

Supernova -> Supernova remnant
GRB-> Afterglow

Macronova -> Radio FlareSummary

Ample independent evidence for r-process
production in rare events with large yield per
event. => SNe 👎 Mergers 👍Macronovae ==> Merger - GRBs connection(even with GW).
nIR Macronovae ==> r-process nucleosynthesis
in Mergers.
Chemical galactic evolution explained if thedistribution of mergers time delay begins at~20 Myr with a constant Galactic SFR

Advertisement - An postdoc opening
under my TReX ERC!

Search for the flare from GRB
130603B by the EVLA

Search for the flare from GRB
130603B by the EVLA

Search for the flare from GRB
130603B by the EVLARadio limits on Magnetars
060614130603B

Horesh + 16

Do GRBs needmagnetars?
Quasars ejectmagnetic jets.
=> GRBs also havemagnetic jets =>Mangetars
But quasars
produce magneticjets withoutmagnetars

Where?
Prompt?
Afterglow?

Is impossible to have both from the samemagnetar?

If a magnetar did thisWhat did that?

If a magnetar did thisWhat did that?

thethedi↵erences
between the
an absolutet only emission
Thesame.
peak ofTherefore,
the cocoonc,af
afterglow
is observed
afte
1
da
generatedbytheshockedjetcocoonarises
due
tothe
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erationradiusandbegins
to
slow
down,
This
density
distribution
andmicrophysics
parameters
tobe(Kanneta
regularGRB
afterglow(generatedbythejet)andoneat tc,af t , once the cocoon’s material reaches the decellum(Madi↵erencesintheisotropic
equivalentenergies
andintheobs
thesame.
Therefore,theonly
di↵erences
betweentheatcocoonaftgenerated
byand
thebeginsshockedjet cocoon
arisesdue
totheeration
radiusto slowdown, This
happens
3
7
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initialLorentz
factors.
an
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regularGRB
afterglow(generatedbythejet)
and
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4
at
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and
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tf emission= arises⇡to10thesec
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weuse
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The
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Hotokezaka, Sari & TP + 16

Efficiency
Hotokezaka, Wajano +…TP 16; Barnes +Photon losses: The ejecta becomesoptically thin to gamma-rays long
before it becomes optically thin to
optical/IR photons => photon
leakage during the macronova
peak (Hotokezaka + 16)
Electron losses: Unlike previous
believes not all the electronsenergy is deposited (Barnes + 16)

SummaryThe nIR flare that followed the short
GRB 130603B could have been aMacronova. If so than:✓Short GRBs arise from mergers.
✓Gold and other A>130 elemets areproduced in mergers. (But large mej).
A radio flare may confirm this!
A second & third Macronovae suggest a
BH-NS merger
244Pu suggests that R-process production
is in rare events.
Cocoon produces a short bright macronova
We wait for the sGRB-GW coincidenceSummaryThe nIR flare that followed the short
GRB 130603B could have been aMacronova. If so than:✓Short GRBs arise from mergers.
✓Gold and other A>130 elemets areproduced in mergers. (But large mej).
A radio flare may confirm this!
A second & third Macronovae suggest aBH-NS merger
244Pu suggests that R-process production
is in rare events.
Cocoon produces a short bright macronova
We wait for the sGRB-GW coincidenceSummary
The nIR flare that followed the short
GRB 130603B could have been aMacronova. If so than:✓Short GRBs arise from mergers.
✓Gold and other A>130 elemets areproduced in mergers. (But large mej).
A radio flare may confirm this!
A second & third Macronovae suggest a
BH-NS merger
244Pu suggests that R-process production
is in rare events.
Cocoon produces a short bright macronova
We wait for the sGRB-GW coincidence