Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries
19
Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries Marek Bartosik & W. Bednarek, A. Sierpowska Erice ISCRA 2004
description
Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries. Marek Bartosik & W. Bednarek, A. Sierpowska Erice ISCRA 2004. The purpose. Neutrinos from massive binaries e.g. Gaisser & Stanev 1985 Berezinsky et al. 1986. large angles – non eclipsing binaries. - PowerPoint PPT Presentation
Transcript of Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries
Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries
Marek Bartosik&
W. Bednarek, A. Sierpowska
Erice ISCRA 2004
6 July 2004 ISCRA Erice 2004 2
The purpose
Neutrinos from massive binaries e.g. Gaisser & Stanev 1985 Berezinsky et al. 1986
large angles – non eclipsing binaries
6 July 2004 ISCRA Erice 2004 3
Binary system
What we need?
Binary with an energetic pulsar
no accretion
small separation
star with massive & fast wind WR or OB – perfect
6 July 2004 ISCRA Erice 2004 4
The shock geometry
The geometry of the shock is described by the parameter
= Lem/(c MlossVWR),
which is the ratio of momentum carried by the pulsar wind and the momentum of the stellar wind.
Lem= 61031B122P-4 erg s-1,
The distance from the pulsar to the termination shock is:
= 1/2D(1+1/2) Ball & Dodd 2001
6 July 2004 ISCRA Erice 2004 5
Scenario
6 July 2004 ISCRA Erice 2004 6
Parameters
KT
skmV
yrMM
eff
WR
sun
5
1
15
104.1
1400
104
GB
msP
sergL
psr
em
11
138
105
59.12
106
=0.06
0.0
6.3
6.1
e
RD
RR
sun
sunWR
Cygnus X-3d=10kpc
6 July 2004 ISCRA Erice 2004 7
Iron from the NS surface
Binding energy of the iron nuclei on the NS surface is not known (2-3keV?).
It is assumed that iron nuclei can be emitted for (Usov&Melrose, 1995)
Temp. of NS star surface can be high enough: In a short time after its formation As a result of heating of the polar cap by e-m cascades
(polar cap model)
KBT 73.012
5105.3
6 July 2004 ISCRA Erice 2004 8
Acceleration of nuclei
Charged particles can be accelerated to the energy
Expected Lorentz factors of iron nuclei in Cyg X-3 cLZeE em /
Arons, 1998
7103~ Arons 0.3 (for Crab)
then - 107
6 July 2004 ISCRA Erice 2004 9
Optical depth
Optical depths for dissociation of single nucleon in the PWZ for different angles of injection (from 0 to 150)
6 July 2004 ISCRA Erice 2004 10
Nucleons extraction
Number of dissolved nucleons from primary iron nuclei during their propagation in the PWZ for angles from 0 to 150
6 July 2004 ISCRA Erice 2004 11
Shock zone
The magnetic field at the termination shock at the „pulsar side” is 103 G
Larmor radius for iron nuclei with Lorentz factor 106 is 1010 cm
Iron nuclei & protons can pass through the shock.
6 July 2004 ISCRA Erice 2004 12
Magnetic field of WR star
)(
)(
)(
)(2
3
3
toroidalrV
VRfor
rr
R
V
V
radialV
VRrrfor
rr
R
dipolerrRforr
R
BrB
rotA
rotrot
AA
A
s
VV
GB
GBG
rot
s
s
)2.01.0(
star) (OB 103
star) (WR 10102
42
VM
RB
rRrR
s
AA
2
)(
)/(/122
4
rA- Alfven radius Eichler & Usov, 1993
6 July 2004 ISCRA Erice 2004 13
Nucleons above the PWZ
Part of nucleons extracted from iron nuclei and remnant nuclei impinge onto the massive star.
Hadrons lose energy on pion production during their propagation in the WR star atmosphere
)()(
)(______
___
eee
pA
Atmosphere model:Hamann 1985
6 July 2004 ISCRA Erice 2004 14
Can we get a neutrino?
If
pion decays and neutrino & muon are produced. decayin ,/,/
/,/ cdecay
s
s6
8
102.2
106.2
6 July 2004 ISCRA Erice 2004 15
Spectra of neutrinos - comparison 0.2 Rstar- red
0.4 Rstar -green0.6 Rstar - blue0.8 Rstar - violet
Lorentz factors -106 thick -107 thin
Modulation due to companion star matter
6 July 2004 ISCRA Erice 2004 16
Integral neutrino fluxes
Integral neutrino fluxes as afunction of the impactparameter for the observerin the plane of the binarysystem at energies above:
102GeV - black3102GeV - red103GeV - green3103GeV – blue(=106 – thick, =107 – thin)
6 July 2004 ISCRA Erice 2004 17
Spectra of neutrinos
Spectra of neutrinos for different viewing angles in respect to the plane of the binary; cos : 0.0-0.2 (black line), 0.2-0.4(red), 0.4-0.6(green) and 0.6-0.8(blue). is azimuthal angle.
=120-150 150-180 180-210
210-240 240-270 270-300
6 July 2004 ISCRA Erice 2004 18
Conclusions Heavy nuclei, if injected by a compact object inside the close massive binary (e.g. similar to Cyg X-3), can significantly disintegrate in the radiation field of a massive star.Some neutrons dissolved from the nuclei impinge on the massive star surface producing high energy neutrinos in the plane of the massive binary. Some protons and neutrons dissolved from nuclei and remnant nuclei, after propagation in the magnetic field of the massive star above the pulsar termination shock, can also impinge on the massive star surface producing neutrinos at large angles to the plane of the binary system. The flux of neutrinos produced at large angles to the system plane is about 30% of the flux produced in the cone intercepted by the massive star in the considered case.
6 July 2004 ISCRA Erice 2004 19
