Cosmic ray acceleration in the MSH supernova remnant (RCW 86) Eveline Helder together with: Jacco Vink, Cees Bassa, Aya Bamba, Johan Bleeker, Stefan Funk, Parviz Ghavamian, Kurt van der Heyden, Frank Verbunt, Ryo Yamazaki

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 2/20 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

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 3/20 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) mV 2

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 4/20 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)

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 5/20 Use optical spectrum to determine proton temperature: H-lines consist of 2 superimposed peaks: narrow reflects T ISM broad reflects T p (Chevalier+ 1980)

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 6/20 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)

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 7/20 RCW 86 X-ray (Chandra) X-ray (blue) + H  (red)

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 8/20 Temperature (H  line) FWHM = 1100 km/s => T p = 2.3 keV

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 9/20

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 10/20

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 11/20 Distance OB association at 2.5 kpc (Westerlund 1969) Local V ISM combined with Galactic rotation curve gives ~2.5 kpc (Rosado+ 1996, Sollerman+ 2003) Blowout seen in CO with same velocity (Matsunaga+ 2001)

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 12/20 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

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 13/20 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 P CR /P Total F CR /F tot

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 14/20

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 15/20

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 16/20

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 17/20

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 18/20

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 19/20 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

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 20/20 Future work Include cross sections for charge exchange in calculating proton temperature Measure proper motion using H  images

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 21/20 Thank you!

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 22/20

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 23/20 Other energy sinks? Magnetic pressure? –B 2 /8  ≈ 0.1nkT –B 2 /8  ~ 0.5 V s /c U c (Bell 2004) U c is the cosmic ray energy density Radiative losses? –This particular part of RCW 86 is non radiative (shows no [SII]-lines) (Smith 1997)

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 24/20 Proper motion (X-ray imaging) 0.5’’ ± 0.2’’ 2.5 kpc => 6000 km/s

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 25/20 HH [SII] Smith, 1997

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 26/20 Heng Van Adelsberg VsVs VsVs Cross section FWHM

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 27/20 Ghavamian Van Adelsberg+ 2008

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 28/20 photon + Shock front

Cosmic ray acceleration in the RCW86 SNR Boston, July 8 th 2009Eveline Helder Utrecht University 29/20 Cosmic ray acceleration (Spitkovsky 2007)