XMM-Newton contribution
1E1207-52
EPIC 230 ksec
1 st direct measurent of the magnetic field of
an isolated neutron star (where cyclotron
absorption is taking place)
1.4 keV
0.7 keV
2.1 keV 2.8 keV
Conclusions
10
For electrons: <B> 8 10
G
14
for protons : <B> 1.6 10 G
PROBLEM
pdot:(1.4 ± 0.3) 10-14 s/s
implies B= 2-3 1012
but also an age of 5 105 y
versus the SN age ( circa 104 ys)
Geminga
EPIC 100 ksec
MOS
Energetics
Edot 3 1034 erg/sec
D = 160 pc
m=170 mas/y
vtr =120 km/sec
Geminga luminosity 3 1031 erg/sec (0.1-5 keV)
Tails luminosity
6.8 1028 erg/sec
The tails account for 2 10-6 Edot

E
2


V
ISM NS
2
4RSO c
V =mD/cos(i)
NS
from bow-shock

E
2


V
ISM NS
2
4RSO c
VNS=mD/cos(i)
we can obtain
0.06 < ISM < 0.15 at/cm3
which implies 7 < M < 20
What produces the X-rays
Power law spectrum -> synchrotron radiation
-> need for electrons and magnetic field
From bow-shock theory
shock = 4 ISM
Since B is frozen-in
Bshock = 4 BISM
Bshock = 10-5 G
To produce keV photons in 10-5 G B field
one needs 1014 eV electrons
1014 eV electrons will have a Larmor radius
of 3.4 1016 cm  thickness 6.8 1016 cm 27”
Caraveo et al. 2003
Science 301, 1345
1014 eV electrons will lose half of their
energy in 800 y .
180 “ / 170 mas/y = 1,000 y
Time-averaged spectroscopy
Pn data ~ 53,000 photons
Timing analysis
Gamma peaks
Common minimum
Phase-resolved spectroscopy
Phase-resolved spectroscopy
Caraveo et al, 2004 Science 305,376
Phase-resolved emission (160 pc)
Conclusions
-hot spot ( ~1.9 M °K), radius 0-60 m
rotating
Probably polar cap seen at 70°-80° inclination
cosq x R (RW/c)1/2 (~300m)
luminosity 1.5 1029 erg/sec
-Cool black-body ( ~.48 M °K), Eurasia size
luminosity 2.6 1031 erg/sec
-Power law photon index 1.7 ± 0.1
luminosity 7.7 1029 erg/sec
Is Geminga unique?
EPIC view of PSRs B1055 & B0656
1055-52
MOS 83 ksec
0656+14
MOS 40 ksec
pn 60 ksec
85,000 photons
pn 35 ksec
120,000 photons
Phase-averaged spectra
Geminga
They all show phase
spectral variations
0656
1055
1055-58
Geminga
0656+14
0656
Cool bb: is it
the surface of
the NS?
 problem
1055-58
Hot bb:
Geminga
rotator
inclinations?
0656+14
0656
hot spot(s)
sizes?
Hot bb: heated polar cap(s) ?
their dimensions are vastly different
although they should not !!!
theoretical cap radii ~250-320 m
real EPIC radii: 60, 800, 1500 m