Download Gravitational waves and neutrino emission from the merger of

Gravitational waves and neutrino
emission from the merger of binary
neutron stars
Ref.) 1105.5035
Kenta Kiuchi
Collaboration with Y. Sekiguchi, K. Kyutoku, M. Shibata
Introduction
Our research target = high energy astrophysical
phenomena
e.g., Supernova energy ≈ 1.5*1046J = energy the
Sun consumes for 1.2 trillion years !!
SN1054 （Crab Nebula）
Energy source = gravitational
potential energy ∝ r-1
～10km
～1000km
r
～Solar mass
Products of high energy astrophysical phenomena
～10km
～3km（1 Solar mass）
✓Density～1015g/cm3 (1.41 g/cm3) ⇒ General Relativity,
Strong interaction
✓Temperature～1011K (15.7×106K)⇒ Weak interaction
✓Magnetic fields～1015 Gauss (Sunspot：several thousand
Gauss)⇒Electromagnetic force
All of fundamental interaction play an essential role.
Physical aspects of high energy astrophysical
phenomena
✓Highly dynamical
✓No special symmetry, e.g., spherical symmetry
⇒Numerical modeling including four kinds of forces
Numerical Relativity
Figuring out high energy astrophysical phenomena
by numerically solving the Einstein equations
Importance of Numerical Relativity
○ Gravitational waves
✓imprinting “raw” information of sources
✓extremely weak signal, hc∼10-22 = the change of (Size of H
atoms)/(Distance to Sun)
GW detectors
Need to prepare
theoretical templates of
GWs
Today’s topic = Coalescence of binary neutron stars
✓Promising source of GWs
✓Theoretical candidate of Short-Gamma-Ray Burst
✓High-end laboratory for Nuclear theory
A nuclear theory ⇒ Mass-Radius relation for Neutron Star
Image of GRB
Black hole
+ disk?
Mass-Radius
Overview of binary neutron star merger
G.Ws. imprint
only information
of mass
Rapidly rotating massive NS
G.Ws. imprint
information of M
total < Mcrit
radius
NS
Mtotal > Mcrit BH and torus
✓Mcrit depends on the Equation of State, i.e. Mcrit = 1.2-1.7 Mmax
✓Final massive NS or torus around BH are extremely hot, T
∼O(10) MeV ⇒Neutrino cooling plays an importance role
Set up of binary neutron star
○ Shen or Shen-Hyperon EOS based on RMF theory (Shen+,98,
Sumiyoshi+,11) ⇒ Mcrit = 2.8-2.9 Solar mass for Shen, 2.3-2.4
Solar mass for Shen-Hyperon EOS
○ Neutrino cooling based on GR leakage scheme (Sekiguchi,10)
○ Equal mass model with 1.35 Solar mass, i.e., Mtot=2.7 Solar
mass
Mass-Radius
Observed BNSs (Lattimer & Paraksh 06)
Observation
constraint
by PSR
J1614-2230
Result
Density color contour on equatorial (x-y) plane =
orbital plane
In units of
millisecond
In units of
Kilometer
Log10(ρ [g/cc])
Gravitational Waveforms
NSs orbit around
each other
Massive NS oscillates
Shen
BH formation
Shen-Hyperon
Gravitational Wave Spectrum
Sensitivity curves for GW detectors
Amplitude
Shen
Shen-Hyperon
frequency
GWs could be detected if the merger happens within 30
Mpc.
Neutrino Luminosity
Anti electron neutrino
Electron neutrino
Shen
Shen+
Hyperon
μ, τ neutrino
BH formation ○
○ Neutrino cooling
timescale ∼ 2-3 second
○ Huge luminosity ∼
1053 erg/s
○ Could be detected if
it happened within 10
Mpc for HK
Summary
○ Binary neutron star merger Numerical Relativity
simulations with microphysical process for the first time
○ GWs could be detected if it happened within 30 Mpc
○ Neutrino could be detected if it happened within 10 Mpc
⇒ Multi messenger astronomy is coming soon !!
Thanks to SR16000 in YITP
Thank you for your attention