magnetars as cooling neutron stars with magnetars as cooling neutron stars with internal heating...
TRANSCRIPT
MAGNETARS AS COOLING NEUTRON STARS WITHMAGNETARS AS COOLING NEUTRON STARS WITH INTERNAL HEATINGINTERNAL HEATING
A.D. Kaminker, D.G. Yakovlev, A.Y. Potekhin, N. Shibazaki*, P. Sternin, and O.Y. Gnedin**
Ioffe Physical Technical Institute, St.-Petersburg, Russia*Rikkyo University, Tokyo 171-8501, Japan **Ohio State University, 760 1/2 Park Street, Columbus, OH 43215, USA
Conclusions
Introduction
Physics input
Games with cooling code
)(TTT ss
Thermal balance:
Photon luminosity:
Heat blanketingenvelope:
ergsTUT2
94810~Heat content:
Cooling theory with internal heating
Main cooling regulators:
1. EOS2. Neutrino emission3. Reheating processes4. Superfluidity5. Magnetic fields6. Light elements on the surface
42L 4 sR T
Heat transport:
( )dT
C T W L Ldt
;dT
Fdr
- effective thermal conductivity
1. EOS: APR III (n, p, e, µ) Gusakov et al. (2005) Akmal-Pandharipande-Ravenhall (1998) -- neutron star models
Parametrization: Heiselberg & Hiorth-Jensen (1999)
2. Heat blanketing envelope: 310 /10 cmgb
sb TT -- relation;
)(sT surface temperature,
;4442 dTLTR seff
effT -- effective temperature;
d -- surface element
( )b bT T
1- SGR 1900+14
2- SGR 0526-66
3- AXP 1E 1841-045
4- AXP 1RXS J170849-400910
5- AXP 4U 0142+61
6- AXP 1E 2259+586
21
H
H0
3. Model of heating:
)exp(1
1)(
2
22
f;)exp(1
1)(
1
11
f at
)exp(),( 210 t
ffHtH
21
10 11 31 23 10 ; 10 ;g cm i
12 12 31 210 ; 3 10 ;g cm ii
13 14 31 23 10 ; 10 ;g cm iii
14 32 ; =9 10 ;g cm iv
No isothermal stage
Core — crust decoupling
yrt 310 1- SGR 1900+14
2- SGR 0526-66
3- AXP 1E 1841-045
4- AXP 1RXS J170849-400910
5- AXP 4U 0142+61
6- AXP 1E 2259+586Only outer layers of heating are appropriate for hottest NSs
Necessary energy input vrs. photon luminosity
)(s
erg into the layer W 1 2
Direct Urca process included
Enchanced thermal conductivity
Appearance of isothermal layers
from min to max
Conclusions
1. High thermal state of magnetars demand a powerful reheating
2. The heating should be located in a thin layer at :11 35 10 g cm
in the outer crust. The heat intensity 0H should range
from 19 3 10 to 20 3 13 10 erg cm s Deeper heating would be extremely inefficient due to neutrino radiation
4. Pumping huge energy into deeper layers can not increase -- effT
5.
.
Temperature distributions within NS are strongly nonuniform due to
thermal decoupling of the outer crust from the inner parts of the star
3. Only ~ 1% of the total energy released in the heat layer can be spent to heat the NS surface