XMM observation of the dynamically young galaxy cluster CL 0939+ ...
The XMM observation of Geminga
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The XMM observation of Geminga 100 ksec of GT time Geminga strikes again
description
The XMM observation of Geminga. 100 ksec of GT time. Geminga strikes again. 70’s. 80’s. The past. 1988 Optical ID G”. EPIC. 1983 X-ray counterpart 1E0630+178. EPIC 2002. >1992 ROSAT 237 msec pulsation EGRET and COS B. >1993 Proper motion of G”. >1996 parallax of G”. - PowerPoint PPT Presentation
Transcript of The XMM observation of Geminga
The XMM observation of Geminga
100 ksec of GT time
Geminga strikes again
70’s80’s
EPICEPIC 2002
Th
e p
ast
1983X-ray counterpart
1E0630+178
1988Optical ID
G”
>1992 ROSAT 237 msec pulsation EGRET and COS B
>1993 Proper motion of G”
>1996 parallax of G”
>1998 absolute position of G”
>1998 Gamma timing with proper motion
>1998 feature in optical
77 x 2 ksec
Energetics Edot 3 1034 erg/secD = 160 pc=170 mas/yvtr =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
224 NSISMSO
VcR
E
VNS=D/cos(i)
i < 30°
RSO < 40”
Geometrical model with i < 30° yields 20” < RSO < 30”
224 NSISMSO
VcR
E
VNS=D/cos(i)
from bow-shock
0.06 < ISM < 0.15 at/cm-3
which implies 7 < M < 20
we can obtain
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
shock = 4 ISM
shock = 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”
1014 eV electrons will loose half of their energy in 800 y . 180 “ / 170 mas/y = 1,000 y
Search for Hemission
No Himplies neutral H < 0.01
Conclusions
Geminga accelerates electrons up to E 1014 eV
The ISM is fully ionized by Geminga
ISM < 2-3 10-6 Gauss
0.06 < ISM < 0.15 at/cm-3
