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Cosmic ray acceleration in the MSH 14-6 3 supernova remnant (RCW 86). Eveline Helder (e.a.helder@uu.nl) together with: Jacco Vink, Cees Bassa, Aya Bamba, Johan Bleeker, Stefan Funk, Parviz Ghavamian, Kurt van der Heyden, Frank Verbunt, Ryo Yamazaki. Supernova remnants as CR accelerators. - PowerPoint PPT Presentation
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Cosmic ray acceleration in the MSH 14-63 supernova
remnant (RCW 86)Eveline Helder (e.a.helder@uu.nl)
together with:
Jacco Vink, Cees Bassa, Aya Bamba, Johan Bleeker, Stefan Funk, Parviz Ghavamian, Kurt van der Heyden, Frank Verbunt, Ryo Yamazaki
Boston, July 8th 2009 Eveline Helder
Utrecht University2/20
Cosmic ray acceleration in the RCW86 SNR
Supernova remnants as CR accelerators
• To maintain energy budget, ~10% of the energy of a SNR needs to go into cosmic rays
• X-ray synchrotron emission has been detected at shock fronts of several supernova remnants
• Several remnants have been observed in gamma-rays
Boston, July 8th 2009 Eveline Helder
Utrecht University3/20
Cosmic ray acceleration in the RCW86 SNR
Imprints of CR acceleration
• Post-shock compression ratio > 4 (Warren+ 2005, Cassam-Chenaï+ 2008, Miceli+ 2009)
• Lower post-shock temperature (Hughes+ 2000)
from conservation of • mass • momentum • and energy
kT = (3/16) mV2
€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University4/20
Cosmic ray acceleration in the RCW86 SNR
Method
• Measure velocity and temperature – V: compare 2 images– T:
• electron temperature contributes only minor part to post-shock pressure, and hard to obtain in spectra dominated by synchrotron emission
• Ion temperatures hard to measure – done in UV (Raymond+ 1995, Ghavamian+ 2007) – done in X-ray (Vink+ 2003)
Boston, July 8th 2009 Eveline Helder
Utrecht University5/20
Cosmic ray acceleration in the RCW86 SNR
• Use optical spectrum to determine proton temperature:
H-lines consist of 2 superimposed peaks:
• narrow reflects TISM
• broad reflects Tp (Chevalier+ 1980)
Boston, July 8th 2009 Eveline Helder
Utrecht University6/20
Cosmic ray acceleration in the RCW86 SNR
RCW 86
• Observed in TeV gamma-rays (Aharonian+ 2009)
• Parts of the rim show X-ray synchrotron emission (Bamba+ 2000, Borkowski+ 2000)
• Can measure the post-shock proton temperature at location of X-ray synchrotron (Smith 1997)
Boston, July 8th 2009 Eveline Helder
Utrecht University7/20
Cosmic ray acceleration in the RCW86 SNR
RCW 86
X-ray (Chandra) X-ray (blue) + H (red)
Boston, July 8th 2009 Eveline Helder
Utrecht University8/20
Cosmic ray acceleration in the RCW86 SNR
Temperature (H line)
FWHM = 1100 km/s => Tp= 2.3 keV
Boston, July 8th 2009 Eveline Helder
Utrecht University9/20
Cosmic ray acceleration in the RCW86 SNR
Boston, July 8th 2009 Eveline Helder
Utrecht University10/20
Cosmic ray acceleration in the RCW86 SNR
Boston, July 8th 2009 Eveline Helder
Utrecht University11/20
Cosmic ray acceleration in the RCW86 SNR
Distance
• OB association at 2.5 kpc (Westerlund 1969)
• Local VISM combined with Galactic rotation curve gives ~2.5 kpc (Rosado+ 1996, Sollerman+ 2003)
• Blowout seen in CO with same velocity (Matsunaga+ 2001)
Boston, July 8th 2009 Eveline Helder
Utrecht University12/20
Cosmic ray acceleration in the RCW86 SNR
Numbers
• Shock velocity is 6000 ± 2800 km/s• FWHM broad line 1100 ± 60 km/s• This would correspond to a shock velocity of
~ 1100 km/s
• We observe the effect of cosmic ray acceleration€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University13/20
Cosmic ray acceleration in the RCW86 SNR
Equations
• Add term for cosmic ray pressure and energy absorbed by cosmic rays to the conservation laws.
• Equation of state goes from 5/3 to 4/3 as pressure gets more cosmic ray dominated
PCR/PTotal
FCR/Ftot
€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University14/20
Cosmic ray acceleration in the RCW86 SNR
€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University15/20
Cosmic ray acceleration in the RCW86 SNR
€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University16/20
Cosmic ray acceleration in the RCW86 SNR
€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University17/20
Cosmic ray acceleration in the RCW86 SNR
€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University18/20
Cosmic ray acceleration in the RCW86 SNR
€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University19/20
Cosmic ray acceleration in the RCW86 SNR
Conclusions
• The effect of cosmic ray acceleration on the kinematics of RCW 86 can not be ignored
• The lower limit to the pressure, contributed by cosmic rays is 50% of the total pressure
Boston, July 8th 2009 Eveline Helder
Utrecht University20/20
Cosmic ray acceleration in the RCW86 SNR
Future work
• Include cross sections for charge exchange in calculating proton temperature
• Measure proper motion using H images
Boston, July 8th 2009 Eveline Helder
Utrecht University21/20
Cosmic ray acceleration in the RCW86 SNR
Thank you!
Boston, July 8th 2009 Eveline Helder
Utrecht University22/20
Cosmic ray acceleration in the RCW86 SNR
€
β =kTp
3/16mpV2
Boston, July 8th 2009 Eveline Helder
Utrecht University23/20
Cosmic ray acceleration in the RCW86 SNR
Other energy sinks?
• Magnetic pressure?– B2/8 ≈ 0.1nkT– B2/8 ~ 0.5 Vs/c Uc (Bell 2004)
• Uc is the cosmic ray energy density
• Radiative losses?– This particular part of RCW 86 is non
radiative (shows no [SII]-lines) (Smith 1997)
Boston, July 8th 2009 Eveline Helder
Utrecht University24/20
Cosmic ray acceleration in the RCW86 SNR
Proper motion (X-ray imaging)
0.5’’ ± 0.2’’ /yr @ 2.5 kpc => 6000 km/s
Boston, July 8th 2009 Eveline Helder
Utrecht University25/20
Cosmic ray acceleration in the RCW86 SNR
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
H [SII]
Smith, 1997
Boston, July 8th 2009 Eveline Helder
Utrecht University26/20
Cosmic ray acceleration in the RCW86 SNR
Heng+ 2007 Van Adelsberg+ 2008
VsVs
Cro
ss s
ectio
n
FW
HM
Boston, July 8th 2009 Eveline Helder
Utrecht University27/20
Cosmic ray acceleration in the RCW86 SNR
Ghavamian+ 2007 Van Adelsberg+ 2008
Boston, July 8th 2009 Eveline Helder
Utrecht University28/20
Cosmic ray acceleration in the RCW86 SNR
photon
photon +
Sho
ck f
ront
Sho
ck f
ront
Boston, July 8th 2009 Eveline Helder
Utrecht University29/20
Cosmic ray acceleration in the RCW86 SNR
Cosmic ray acceleration
(Spitkovsky 2007)
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