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Mass ejec(on from NSNS merger and Kilonova/Macronova Kenta Hotokezaka (Hebrew University of Jerusalem) Collaborators: K. Kiuchi, T. Muranushi, Y. Sekiguchi, and M. Shibata (YITP) K. Kyutoku (UWM), H. Okawa (Waseda U), and K. Taniguchi (U. of Tokyo) M. Tanaka (NAOJ), S. Wanajo (RIKEN) T. Piran (Hebrew U. of Jerusalem)

Mass$ejec(on$from$NS0NS$merger$ and$ … · NS0NS$merger$:$Dynamics$and$GW$waveform$ log(density$g/cc) Numerical$relavity$computaon. ... GRB$jet NS0NS$breakout GRB$jet:$$ $$$$Nakar(2007)

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Page 1: Mass$ejec(on$from$NS0NS$merger$ and$ … · NS0NS$merger$:$Dynamics$and$GW$waveform$ log(density$g/cc) Numerical$relavity$computaon. ... GRB$jet NS0NS$breakout GRB$jet:$$ $$$$Nakar(2007)

Mass  ejec(on  from  NS-­‐NS  merger  and  

Kilonova/Macronova

Kenta  Hotokezaka    (Hebrew  University  of  Jerusalem)

Collaborators:                                K.  Kiuchi,  T.  Muranushi,  Y.  Sekiguchi,  and  M.  Shibata  (YITP)                              K.  Kyutoku  (UWM),  H.  Okawa  (Waseda  U),  and  K.  Taniguchi  (U.  of  Tokyo)                              M.  Tanaka  (NAOJ),  S.  Wanajo  (RIKEN)                              T.  Piran  (Hebrew  U.  of  Jerusalem)

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Outline

•  Electromagne(c  counterparts  of  Gravita(onal  waves  

•  Mass  ejec(on  at  binary  neutron  star  merger  

•  A  kilonova/macronova  candidate  associated  with  a  short  GRB  130603B

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Gravita(onal-­‐wave  astronomy

Advanced  LIGO Advanced  Virgo KAGRA

GW Compact  binary  merger   GW

Expected  rate(NS-­‐NS  merger)

1st  genera(on  (Ini(al  LIGO,  Virgo)                  2nd  genera(on(Advanced  LIGO,  Virgo,  KAGRA)

0.0002  〜 0.2  /yr                                                  0.4  〜  400  /yr

Abadie  et  al  (2010)

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M1 =1.4Msun

M2 =1.3Msun

density

Hotokezaka,  et  al.  (2013)  

NS-­‐NS  merger  :  Dynamics  and  GW  waveform  

log(density  g/cc)

Numerical  rela(vity  computa(on.

Waveform

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Gravita(onal  wave  from  compact  binary  merger

-2e-21

-1e-21

0

1e-21

2e-21

2 2.01 2.02 2.03 2.04 2.05

h

time[s]

Data:Noise+GW

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

2 2.01 2.02 2.03 2.04 2.05

h

time[s]

Theore(cal  Template

Compute  the  overlap  between  data  and  template    

Matched  filter  analysis

Because  the  advanced  detectors  will  watch  〜10^5  galaxies,  many  signals  will  be  expected  around  the  detec(on  threshold.  

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Electromagne(c  counterparts  of  GWs  ü  Confirma(on  of  the  detec(on  of  GWs  from  NS-­‐NS              around  detec(on  threshold,    (like  Neutrino  burst  associated  with  supernova  1987A)        ü  Localiza(on  of  GW  sources  (GW  localiza(on  is  not  good),              =>  Determine  host  galaxies.  

ü  They  carry  different  informa(on  from  GWs.              (e.g.  Mass  of  ejected  radioac(ve  nuclei)      

           But  to  discover  them  won’t  be  easy.    =>  Theore(cal  expecta(ons  are  needed  to  make  observa(onal  strategies.

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Baryon  ejec(ons  drive  EM  counterparts

1,Dynamical  ejecta:  Tidal  tail  &  shocked  majer  

Hypermassive  NS  with  accre(on  torus

Black  hole  with  accre(on  torus

or

2,  Wind  driven  by  viscosity,  neutrino,  recombina(on 3,  A  GRB  jet  may  be  launched  at  a  certain  (me.

Wind

GRB  Jet

NS-­‐NS  Merger

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30  

 28    26    

-­‐2                                          0                                          2                                          4                                            6                                          8                                      10

log(L)  [e

rg/s]  

Log  

Luminosity

(erg/s/Hz)  

log(t)  [s]

Merger  remnant     (radio)

Kilonova  /Macronova  (NIR)

 Extended  Emission  (X)

GRB  Anerglow  (X)

Merger  Breakout  (X)

GRB  Anerglow  (visible)

GRB  anerglow                  (radio)

GRB  (X~γ) 52    

50    

48    

46    

44    

42    

log(Lν)  [erg/s/Hz

]  

Merger  Breakout  (radio)

Expected  Lightcurve Refs:  Nakar  (2007)  

               Norris  &  Bonnell  (2006)                  Sari,  Piran,  Narayan  (1998)  

               Li  &  Paczynski  (1998)                  Nakar  &  Piran  (2012)  

               Kyutoku,  Ioka,  Shibata  (2012)                  Kelley,  Mandel,  Ramirez-­‐Ruiz  (2012)

Luminosity

(me

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30  

 28    26    

-­‐2                                          0                                          2                                          4                                            6                                          8                                      10

log(L)  [e

rg/s]  

Log  

Luminosity

(erg/s/Hz)  

log(t)  [s]

Merger  remnant     (radio)

Kilonova  /Macronova  (NIR)

 Extended  Emission  (X)

GRB  Anerglow  (X)

Merger  Breakout  (X)

GRB  Anerglow  (visible)

GRB  anerglow                  (radio)

GRB  (X~γ) 52    

50    

48    

46    

44    

42    

log(Lν)  [erg/s/Hz

]  

Merger  Breakout  (radio)

(me

Luminosity Expected  Lightcurve  (4π)

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30  

 28    26    

-­‐2                                          0                                          2                                          4                                            6                                          8                                      10

log(L)  [e

rg/s]  

Log  

Luminosity

(erg/s/Hz)  

log(t)  [s]

Merger  remnant     (radio)

Kilonova  /Macronova  (NIR)

 Extended  Emission  (X)

GRB  Anerglow  (X)

Merger  Breakout  (X)

GRB  Anerglow  (visible)

GRB  anerglow                  (radio)

GRB  (X~γ) 52    

50    

48    

46    

44    

42    

log(Lν)  [erg/s/Hz

]  

Merger  Breakout  (radio)

(me

Luminosity Expected  Lightcurve(4π,  independent  of  environment)

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What  is  “kilonova/macronova”

A  kilonova/macrovova  was  proposed  by  Li  &  Paczynski  in  1998                                                  as  an  observable  consequence  of  NS-­‐NS  mergers.  

At  NS-­‐NS  merger  ü  A  frac(on  of  material  is  ejected  as  radioac(ve  nuclei.  ü  Ejecta  can  be  bright  object  due  to  radioac(ve  hea(ng.  ü   Luminosity:  Nova  <  NS-­‐NS  merger  <  Supernova.

Beta  decay  of  radioac(ve  nuclei  =>  Keep  ejecta  at  high  T

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Kilonova/Macronova  and  Ejecta  property Luminosity

     erg/s

(me

∝Mejt−1.3

Diffusion  (me ∝ v−2/3M 1/3ej

Based  on  current  understanding    

〜  100  –  1000  x  Nova  (at  the  peak  of  a  lightcurve)  

〜5  days

ü  Higher  ejecta  mass  =>  Brighter  signal  ü  Faster  ejecta  velocity  =>  Brighter  signal  

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0.01

0.1

1

10

1e-07 1e-06 1e-05 0.0001 0.001 0.01 0.1

E K/1

050er

g

M/Msun

GRNewton

GRB jet(K=30)GRB cocoon

BH-torus windHMNS wind

NS-NS breakout

Various  ouylows  of  NS-­‐NS  merger  

GRB  jet

NS-­‐NS  breakout

GRB  jet:            Nakar  (2007)  GRB  cocoon:          Nagakura  et  al  (2014)  NS-­‐NS  merger  breakout:          Kyutoku,  Ioka,  &  Shibata  (2013)  Dynamical  ejecta:          Hotokezaka  et  al.  (2013)            Piran  et  al.  (2013)          Bauswein  et  al.  (2013)  BH-­‐torus  wind:          Fernandez  &  Metzger  (2013)          Just  et  al.  (2014)  HMNS  –  torus  wind:          Dessart  et  al.  (2009)            Metzger  &  Fernandez  (2014)          Perego  et  al.  (2014)

Γ>30

Dynamical  ejecta  is  likely  dominant  source  of  kilonova/macronova.  

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Numerical  simula(on  for  dynamical  ejecta

of the system for the outside of the horizon. However, thispathology could still break a numerical simulation after theformation of a black hole. To avoid this happens, weartificially set the maximum density as 1016 g=cm3 whenemploying this EOS.

Figure 2 plots the gravitational mass as a function of thecentral density and as a function of the circumferentialradius for spherical neutron stars for four EOSs. All theEOSs chosen are stiff enough that the maximum mass islarger than 1:97M!. Because the pressure in a densityregion ! & 1015 g=cm3 is relatively small (i.e., P2 issmall) for APR4 and ALF2, the radius for these EOSs isrelatively small as "11 km and 12.5 km, respectively, forthe canonical mass of neutron stars 1:3–1:4M! [38]. Bycontrast, for H4 and MS1 for which P2 is relatively large,the radius becomes a relatively large value 13.5–14.5 kmfor the canonical mass. The radius has also the correlationwith the central density !c. For APR4 and ALF2 withM#1:35M!, !c$8:9%1014 g=cm3 and !c $ 6:4%1014 g=cm3. For H4 and MS1 with M # 1:35M!, thecentral density is rather low as !c $ 5:5% 1014 g=cm3

and !c $ 4:1% 1014 g=cm3, respectively. As we show inSec. IV, the properties of the material ejected from themerger of binary neutron stars depend strongly on theradius of the neutron stars or !c.

B. Initial conditions

We employ binary neutron stars in quasiequilibria forthe initial condition of numerical simulations as in ourseries of papers [24,25]. The quasiequilibrium state iscomputed in the framework described in [39] to whichthe reader may refer. The computation of quasiequilibriumstates is performed using the spectral-method libraryLORENE [40].

Numerical simulations were performed, systematicallychoosing wide ranges of the total mass and mass ratio ofbinary neutron stars. Because the mass of each neutron star

in the observed binary systems is in a narrow range"1:2–1:45M! [38], we basically choose the neutron-starmass 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, and 1:5M!. Also,the mass ratio of the observed system q :# m1=m2&' 1(where m1 and m2 are lighter and heavier masses, respec-tively, is in a narrow range"0:85–1. Thus, we choose q as0:8 ' q ' 1. Specifically, the simulations were performedfor the initial data listed in Table II.The initial data were prepared so that the binary has

about 3–4 quasicircular orbits before the onset of themerger. For four EOSs chosen, this requirement is approxi-mately satisfied with the choice of the initial angularvelocity m!0 # 0:026 for APR4 and ALF2 andm!0 # 0:025 for H4 and MS1. Here, m # m1 )m2.For the following, the model is referred to as the name‘‘EOS’’-‘‘m1’’ ‘‘m2’’; e.g., the model employing APR4,m1 # 1:2M!, and m2 # 1:5M! is referred to as modelAPR4-120150.

III. FORMULATION AND NUMERICALMETHODS

Numerical simulations were performed using anadaptive-mesh refinement (AMR) code SACRA [41] (seealso [42] for the reliability of SACRA). The formulation, thegauge conditions, and the numerical scheme are basicallythe same as those described in [41], except for the improve-ment in the treatment of the hydrodynamics code for a farregion. Thus, we here only briefly review them anddescribe the present setup of the computational domainfor the AMR algorithm and grid resolution.

A. Formulation and numerical methods

SACRA solves Einstein’s evolution equations in theBaumgarte-Shapiro-Shibata-Nakamura formalism with amoving-puncture gauge [43]. It evolves a conformal factorW :# "*1=6, the conformal three-metric ~"ij :# "*1=3"ij,the trace of the extrinsic curvature K, a conformally

0 1e+15 2e+15

M (s

olar

mas

s)

!c (g/cm3) 10 15 20

M (s

olar

mas

s)

R (km)

0

0.5

1

1.5

2

2.5

3APR4

ALF2

H4

MS1

APR4ALF2

H4

MS1 0

0.5

1

1.5

2

2.5

3

FIG. 2 (color online). Left: The gravitational mass as a function of the central density !c for spherical neutron stars in APR4, ALF2,H4, and MS1 EOSs (the solid, dashed, dotted, and dash-dotted curves). Right: The same as the left panel but for the gravitational massas a function of the circumferential radius.

KENTA HOTOKEZAKA et al. PHYSICAL REVIEW D 87, 024001 (2013)

024001-4

We  perform    Numerical  Rela(vity  simula(ons  using  SACRA  code  Yamamoto  +  2009                                        Solve          ・Einstein  equa(on        ・Hydrodynamics            with  an  Equa(on  of  State          (4-­‐different  NS  models)      Total  mass  =  2.6  ~  2.9  Msun  Mass  ra(o  =  0.8  ~  1  

For  piecewise  polytropic  EOSs  See  Read  et  al.,  (2009)  

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Mass  ejec(on  on  equatorial  plane

300  km  x  300  km                                                                  2400  km  x  2400  km

Model  :  1.2Msun  –  1.5Msun,    APR

log(density  g/cc)

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300  km  x  300  km                                                                  2400  km  x  2400  km

Model  :  1.2Msun  –  1.5Msun,    APR

log(density  g/cc)

Mass  ejec(on  :  Mej  〜  0.01Msun,  v  〜  0.2c

Mass  ejec(on  on  equatorial  plane

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Ejec(on  Mechanism  ~(dal  torque~

Heavy  NS

Light  NS

1.  Lighter  NS  is  elongated  

2.  Outer  material  get  angular  momentum    

Feature:          Ejecta  expand  on                    the  equatorial  plane  

log(density  g/cc)

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300  km  x  150  km                                                                  2400  km  x  1200  km

Model  :  1.2Msun  –  1.5Msun,    APR

log(density  g/cc)

Mass  ejec(on  on  the  Meridional  plane (x-­‐z  plane)

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300  km  x  150  km                                                                  2400  km  x  1200  km

Model  :  1.2Msun  –  1.5Msun,    APR

log(density  g/cc)

Mass  ejec(on  on  the  Meridional  plane (x-­‐z  plane)

NS-­‐NS  Ejecta  is  spheroidal.  

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Ejec(on  Mechanism  ~shock  hea(ng~

Model=135Msun-­‐1.35Msun,  APR

12

0

5e+14

1e+15

1.5e+15

0 10 20 30 40

ρ c (g

/cm

3 )

t (ms)

APR4-135135ALF2-135135

H4-135135MS1-135135

0

5e+14

1e+15

1.5e+15

0 10 20 30 40

ρ c (g

/cm

3 )

t (ms)

APR4-120150ALF2-120150

H4-120150MS1-120150

FIG. 6: The central density as a function of time for models with m1 = m2 = 1.35M� (left), and m1 = 1.2M� and m2 = 1.5M�(right). Before the merger of unequal mass binaries, the central density of heavier neutron stars are plotted. �th = 1.8 isemployed for the results presented here.

FIG. 7: Snapshots of the thermal part of the specific internal energy ("th) profile in the vicinity of HMNSs on the equatorial(top) and x-z (bottom) planes for an equal-mass model APR4-135135. The rest-mass density contours are overplotted for everydecade from 1015 g/cm3.

Figures 3 – 5 indicate that there are two importantprocesses for the mass ejection. The first one is theheating by shocks formed at the onset of the mergerbetween the inner surfaces of two neutron stars. Fig-ures 7 and 8 display snapshots of the thermal part of thespecific internal energy, "th, in the vicinity of HMNSs

for APR4-135135 and APR4-120150, respectively. Thesefigures show clearly that hot materials with "th <⇠ 0.1(1.0 <⇠ 100MeV) are indeed ejected from the HMNSs,in particular, to bidirectional regions on the equatorialplane and to the polar region. This suggests that theshock heating works e�ciently to eject materials from

Specific  internal  energy

Spiral  arm                          sweeps  majer                Mass  is  ejected  due  to    the  HMNS  forma(on            

Equatorial  plane

Meridian  plane

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2

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11 12 13 14 15

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Dependence  of  Ejecta  mass  on  NS  EOS

Radius  of  NS  

Mass  of  Ejecta Systematics of dynamical mass ejection, nucleosynthesis, and radioactively powered electromagnetic signals 9

10 11 12 13 14 15 160

0.002

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0.315

0.32

0.325

0.33

0.335

0.34

0.345

|v1|+

|v2| [

c]

R1.35 [km]

Fig. 3.— Amount of unbound material for 1.35-1.35 M! mergers (top left) and 1.2-1.5 M! mergers (top right) for di!erent EoSscharacterized by the corresponding radius R1.35 of a nonrotating NS. Red crosses denote EoSs which include thermal e!ects consistently,while black (blue) symbols indicate zero-temperature EoSs that are supplemented by a thermal ideal-gas component with "th = 2 ("th = 1.5)(see main text). Small symbols represent EoSs which are incompatible with current NS mass measurements (Demorest et al. 2010). Circlesdisplay EoSs which lead to the prompt collapse to a black hole. The lower panels display the sum of the maxima of the coordinate velocitiesof the mass centers of the two binary components as a function of R1.35 for symmetric (bottom left) and asymmetric (bottom right)binaries.

ima of the coordinate velocities of the mass centers ofthe two asymmetric binary components. As in the sym-metric case the two stars collide with a higher impactvelocity if the initial radii of the NSs are smaller.Due to the asymmetry the dynamics of the merger pro-

ceeds di!erently from the symmetric case (see Fig. 4).Prior to the merging the less massive binary componentis deformed to a drop-like structure with the cusp point-ing to the 1.5 M! NS (top panels). After the stars beginto touch each other, the lighter companion is stretchedand a massive tidal tail forms (middle left panel). Thedeformed 1.2 M! component is wound around the moremassive companion (middle panels). Also in the case ofasymmetric mergers the majority of the ejecta originatesfrom the contact interface of the collision, i.e. from thecusp of the “tear drop” and from the equatorial surfaceof the more massive companion, where the impact ab-lates matter (see top panels). Some matter at the tipof the cusp directly fulfills the ejecta criterion (top rightpanel), while the majority obtains an additional pushby the interaction with the asymmetric, mass-shedding

central remnant and the developing spiral arms (middleright and bottom panels). A smaller amount of ejecta ofroughly 25 per cent originates from the outer end of theprimary tidal tail (particles in the lower part of the topright panel). A part of this matter becomes unbound bytidal forces (at the tip of the tidal tail in the middle leftpanel) and the other fraction by an interaction with thecentral remnant (middle left panel).Figure 5 displays the distribution of the ejecta in a

plane perpendicular to the binary orbit for the symmetricmerger (left panel) compared to the asymmetric merger(right panel) for the last timesteps shown in Fig. 2 andFig. 4, respectively. A considerable fraction of the ejectedmatter is expelled with large direction angles relative tothe orbital plane. For a timestep about 5 ms later theejecta geometry is visualized (azimuthally averaged) inFig. 6 excluding the bound matter. For both mergersthe outflows exhibit a (torus or donut-like) anisotropywith an axis ratio of about 2:3. The velocity fields alsoshow a slight dependence on the direction.

Hotokezaka  +  (2013)

Bauswain  +  (2013)

If  HMNS  is  formed,

No  massive  neutron  star  forma(on

Similar  result  is  obtained  by  MPS  group.

0.0001<Mej<0.01Msun

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Velocity  distribu(on

0.001

0.01

0.1

0.001 0.01 0.1 1

dM/d

v

v

Most  of  ejecta  has  the  velocity  0.1c  〜0.2c

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Radiative Transfer Simulations for NS Merger Ejecta 9

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tude

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K band200 Mpc

4m

space

Fig. 8.— Expected observed ugrizJHK-band light curves (in AB magnitude) for model NSM-all and 4 realistic models. The distanceto the NS merger event is set to be 200 Mpc. K correction is taken into account with z = 0.05. Horizontal lines show typical limitingmagnitudes for wide-field telescopes (5! with 10 min exposure). For optical wavelengths (ugriz bands), “1 m”, “4 m”, and “8 m” limitsare taken or deduced from those of PTF (Law et al. 2009), CFHT/Megacam, and Subaru/HSC (Miyazaki et al. 2006), respectively. ForNIR wavelengths (JHK bands), “4 m” and “space” limits are taken or deduced from those of Vista/VIRCAM and the planned limits ofWFIRST (Green et al. 2012) and WISH (Yamada et al. 2012), respectively.

Radiative Transfer Simulations for NS Merger Ejecta 9

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tude

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4m

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tude

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K band200 Mpc

4m

space

Fig. 8.— Expected observed ugrizJHK-band light curves (in AB magnitude) for model NSM-all and 4 realistic models. The distanceto the NS merger event is set to be 200 Mpc. K correction is taken into account with z = 0.05. Horizontal lines show typical limitingmagnitudes for wide-field telescopes (5! with 10 min exposure). For optical wavelengths (ugriz bands), “1 m”, “4 m”, and “8 m” limitsare taken or deduced from those of PTF (Law et al. 2009), CFHT/Megacam, and Subaru/HSC (Miyazaki et al. 2006), respectively. ForNIR wavelengths (JHK bands), “4 m” and “space” limits are taken or deduced from those of Vista/VIRCAM and the planned limits ofWFIRST (Green et al. 2012) and WISH (Yamada et al. 2012), respectively.

Op(cal Near  Infrared

Tanaka  &  KH  2013  

Expected  lightcurves  of  kilonova/macronova Masaomi-­‐san’s  talk  in  detail

〜0.01Msun

〜0.004Msun

We  should  follow  up  GW  events  with  telescopes  larger  than  4m-­‐size.

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A  Golden  event:  the  short  GRB  130603B          〜  kilonova/macronova  candidate〜        

ü  This  could  be  direct  evidence  of                compact  binary  merger  hypothesis  of  short  GRBs.    ü  Macronovae  will  be  promising  EM  counterpart  of  GWs.      ü  A  compact  binary  merger  really  produces  〜0.02Msun              of  r-­‐process  elements      

Tanvir  et  al.,Nature,2013  Berger  et  al.,  ApJ,  2013  de  Ugarte  Pos(go  et  al,  2013

If  this  event  is  really  “Kilonova/Macronova”  

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10−10

10−9

10−8

10−7

10−6

10−5

10−4

10−3

0.01

Flux

den

sity

(Jy

@ 1

0 ke

V)

BAT: Black −− XRT: WT: Blue; PC: RedBAT−XRT data of GRB 130603B

0.01 0.1 1 10 100 1000 104 105 106 1070

1

2

3

K

Time since BAT trigger (s)

Short  GRB130603B hjp://www.swin.ac.uk/burst_analyser/00557310/

T90 = 0.18± 0.02s

Eγ ,iso = (2.1± 0.1)×1051erg

redshin  z=0.356

GRB  prompt  emission  Swin  BAT

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Short  GRB  130603B 

Figure 9: Light curves of GRB 130603B, indicated detections with dots and upper limits (3-�) with arrows. V -band photometry has been scaled and plotted together with the g-band. The vertical lines indicate the times whenspectra were obtained. Dotted lines indicate the light curve fits to a power law temporal decay from 0.3 to 3 daysafter the burst. We include data from the literature [21, 22]. The dashed blue line is the expected r-band lightcurve of a supernova like SN1998bw, the most common template for long GRBs after including an extinction ofAV = 0.9 magnitude. The most constraining limits indicate that any supernova contribution would be at least 100times dimmer than SN 1998bw in the r-band, once corrected of extinction (blue dashed-dotted line).

2.2 Spectral energy distribution of the afterglow and extinction

In this section we aim to fit the X-ray to optical/NIR SED using the method followed in [23, 24] to derive the

extinction in the line of sight of the GRB and determine some spectral parameters. The procedure is briefly

explained below.

The flux calibrated spectrum has been analysed after removing wavelength intervals affected by telluric lines

and strong absorption lines. We then rebinned the spectrum in bins of approximately 8 A by a sigma-clipping

algorithm. To check the flux calibration of the X-shooter spectrum, we compare the continuum with the flux

densities obtained from the extrapolation of the photometry at the time of the spectrum (mid time around 8.56 hr).

We include the X-ray spectrum from the X-ray telescope (XRT) on board Swift. We used XSELECT (v2.4) to

26

de  Ugarte  Pos(go  et  al  2013

Flux

(me

GRB  anerglow(X-­‐ray)

Swin  XRT

Near-­‐infrared  excess  Hubble  Space  telescope  

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Page 8 of 16

Figure 1 HST imaging of the location of SGRB 130603B. The host is well resolved

and displays a disturbed, late-type morphology. The position (coordinates RAJ2000 = 11

28 48.16, DecJ2000 = +17 04 18.2) at which the SGRB occurred (determined from

ground-based imaging) is marked as a red circle, lying slightly off a tidally distorted

spiral arm. The left-hand panel shows the host and surrounding field from the higher

resolution optical image. The next panels show in sequence the first epoch and second

epoch imaging, and difference (upper row F606W/optical and lower row F160W/nIR).

The difference images have been smoothed with a Gaussian of width similar to the psf,

to enhance any point-source emission. Although the resolution of the nIR image is

inferior to the optical, we clearly detect a transient point source, which is absent in the

optical.

u Hubble  Space  Telescope  imaging

Op(cal            

Near  Infrared

9  days  aner  the  burst                         30  days                          

The  host  galaxy

Tanvir  et  al.,Nature,2013  Berger  et  al.,  ApJ,  2013  

A  macronova  associated  with  the  short  GRB  130603B?  

macronova  candidate

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Radiative Transfer Simulations for NS Merger Ejecta 9

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Fig. 8.— Expected observed ugrizJHK-band light curves (in AB magnitude) for model NSM-all and 4 realistic models. The distanceto the NS merger event is set to be 200 Mpc. K correction is taken into account with z = 0.05. Horizontal lines show typical limitingmagnitudes for wide-field telescopes (5! with 10 min exposure). For optical wavelengths (ugriz bands), “1 m”, “4 m”, and “8 m” limitsare taken or deduced from those of PTF (Law et al. 2009), CFHT/Megacam, and Subaru/HSC (Miyazaki et al. 2006), respectively. ForNIR wavelengths (JHK bands), “4 m” and “space” limits are taken or deduced from those of Vista/VIRCAM and the planned limits ofWFIRST (Green et al. 2012) and WISH (Yamada et al. 2012), respectively.

Radiative Transfer Simulations for NS Merger Ejecta 9

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Fig. 8.— Expected observed ugrizJHK-band light curves (in AB magnitude) for model NSM-all and 4 realistic models. The distanceto the NS merger event is set to be 200 Mpc. K correction is taken into account with z = 0.05. Horizontal lines show typical limitingmagnitudes for wide-field telescopes (5! with 10 min exposure). For optical wavelengths (ugriz bands), “1 m”, “4 m”, and “8 m” limitsare taken or deduced from those of PTF (Law et al. 2009), CFHT/Megacam, and Subaru/HSC (Miyazaki et al. 2006), respectively. ForNIR wavelengths (JHK bands), “4 m” and “space” limits are taken or deduced from those of Vista/VIRCAM and the planned limits ofWFIRST (Green et al. 2012) and WISH (Yamada et al. 2012), respectively.

Observa(on  by  Hubble  Space  Telescope

Op(cal Near  Infrared

Tanaka  &  KH  2013  

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More  than  〜0.01Msun  r-­‐process  ejecta  are  ejected

Hotokezaka  et  al  ApJL  (2013)  

20

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30 0.1 1 10

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nitu

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B)

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SLy(Mej=0.02)H4(Mej=0.004)

rH

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MS1(Mej=0.07)H4(Mej=0.05)

APR4(Mej=0.01)r

H

Figure 8.3: Predicted light curves for NS–NS and BH–NS models. Left panel: NS–

NS models. The dashed, solid, and dot-dashed curves show the H-band light curves

for the models: SLy (Q = 1.0, Mej = 0.02M!), H4 (Q = 1.25, Mej = 4 ! 10"3M!),

respectively. The total mass of the progenitor is fixed to be 2.7M!. The upper, middle,

and lower curves for each model correspond to the high-, fiducial- and low-heating models.

Right panel: BH-NS models. The dashed, solid, and dot-dashed curves show the models

MS1 (Mej = 0.07M!), H4 (Mej = 0.05M!), and APR4 (Mej = 0.01M!), respectively.

Here only the fiducial-heating models are shown. The thin and thick lines denote the

r and H-band light curves. Here we set (Q, !) = (3, 0.75). The observed data (filled

circles), upper limits (triangles), and the light curves (dashed lines) of the afterglow model

of GRB 130603B in r and H-band are plotted (Tanvir et al. 2013; de Ugarte Postigo et al.

2013). The observed point in r-band at 1 days after the GRB is consistent with the

afterglow model. The key observations for a kilonova are the observed H-band data at

7 days after the GRB, which exceed the H-band light curve of the afterglow model, and

the upper limit in H-band at 22 days after the GRB. These data suggest the existence

of a kilonova associated with GRB 130603B. This figure is taken from Hotokezaka et al.

(2013d).

124

Observed  point  

Expected  lightvurve              Mej〜0.02Msun  

Expected  lightcurve              Mej〜0.004Msun  

If  dynamical  ejecta  are  dominant  contribu(on  to  this  bump.

The  observed  lightcurves  can  be  explained  with  Kilonova/Macronova  Produced  by  dynamical  ejecta  〜0.02Msun

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GW  –  EM  observa(on  and  r-­‐process

1,  GW  observa(on                                                            when/where  we  should  follow  up.      2,  EM  observa(on                                                      Total  mass  of  ejecta  can  be  es(mated.                                                                                                                              (r-­‐process  element)        3,  Collec(ng  many  events                                                            [mass/yr/galaxy] mr (r)

In  order  to  achieve  this,    precise  understanding  of  nuclear  hea(ng  and    opacity  for  various  type  of  ejecta  is  important.  

Rebecca,  Oleg,  Shinya,  and  Masaomi’s  talks

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Summary Detec(on  of  Electromagne(c  counterparts  will  be  important.                      They  depend  on  baryon  ouylows.    0.0001Msun  –  0.01Msun  of  baryons  will  dynamically  ejected  with  Velocity  0.1c  –  0.3c.    A  Kilonova/Macronova  candidate  associated  with  a  short    GRB  13060Bhas  discovered.  Es(mated  dynamical  ejecta  〜0.02Msun.    Future  We  should  understand    possible  parameter  space  of  ejecta  mass,  velocity,  opacity,  and  hea(ng  rate  for  various  type  of  ejecta  to  es(mate  ejecta  mass.