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X-ray Image of Comet C/Linear 1999 Lisse et al. , Science (2001)

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X-ray Image of Comet C/Linear 1999 Lisse et al. , Science (2001)

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  1. Charge-Exchange Mechanism of X-ray EmissionV. Kharchenko ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge1. Introduction- interaction between the solar/stellar wind and neutral gas - X-rays induced in the charge-exchange(CX) collisions- CX mechanism of X-ray emission from the Jupiter atmosphere2. X-ray spectra induced by CX collisions - selective population of excited states of highly charged ions - X-ray and EUV radiative cascading spectra - diagnostic of ion compositions and velocities3. Conclusions.Acknowledgments to my coauthors:Alex DalgarnoRon PepinoRosine LallementMatt Rigazio

  2. X-ray Imageof Comet C/Linear 1999 Lisse et al. , Science (2001) X-rays Sun visual light

  3. X-ray Image of Comet McNaught-HartleyKrasnopolsky et al. (2002)observed with the Chandra X-ray telescope

  4. ROSAT data Photon Energy [keV] EUV X-ray hν OVII (23S --11S) 561eV Krasnopolsky et al. (2001) Lisse et al. (2001)

  5. Interaction between the Solar Wind and Neutral Gases in the Heliosphere Zq+ = O7+, C6+ , N7+ , Fe13+, Mg10+ … He Z q+ + A Z*(q-1) + A+ H Interstellar gas X-ray Photons fast solar wind slow wind Planetary Atmospheres Cometary Atmospheres H Cravens (1997) H2O O

  6. X-ray emission from the polar regions of the Jupiter atmosphere Precipitation of energetic ions Oq+ and Sq+ into the Jupiter atmosphere. Ion energies: < MeV/amu Highly charged ions are produced by stripping collisions between precipitating magnetospheric ions and atmospheric atoms (molecules): I : Oq+ + H  O(q+1)+ + e + H II : O(q+1)+ + H  O(q+2)+ + e + H ……………………….. N: O(q+n)+ + H  O*(q+n-1)+ + H+ hn Magnetospheric ions Sq+ Oq+ Magnetic field Jupiter

  7. Charge-Transfer Collisions ... minor SW ions: Oq+, Cq+ , Feq+ O nucleus H H+and He2+ H2O Volume Emission Rate: W = ng nions viσ P (hν) Dust particles collision rate photon yield Aq+ + B A*(q-1)+ + B+ electron H Number of photons hν hν Oq+ Photon energy hn

  8. Emission Spectra of Oxygen Ions O(q+1)+ + H  O*q+ + H+

  9. X-rays induced by O*7+ ions in collisions of O*8+ with He atoms 2p - 1s

  10. C*4+ EUV CASCADING PHOTONS C5+ + H2 C*4+ + H2+ EXPERIMENT Suraud et al.,1991 Å 180 220 260 THEORY Å 180 220 260 WAVELENGTH

  11. POPULATION OF ION EXCITED STATES IN ELECTRON-CAPTURE COLLISIONS H2O electron Neutral atoms and molecules CO, O, He, H X-ray photon hν n-2 n-1 ion core n Multiplet Structure of Electronic States Singlet states S=0 Triplet states S=1 s p d f s p d f n 4 3 t = 0.001s L= 400m 2 23P 23Smetastable state 1 GROUND STATE Helium-like ions: C4+ , N5+ , O6+

  12. O*6+ emission spectra detected in ion beam experiments[Greenwood et al. (2001)]Theoretical spectra: photon cascading [Kharchenko et al.(2003) ] {n,L} state-selective populations from the recoil-momentum spectroscopy measurements [Hasan et al. (2001)]

  13. Solar Wind Electrons and Ions Major Ions H+ and He 2+ Minor Ions Oq+: O5+ O6+ O7+ O8+ Cq+: C4+ C5+ C6+ Neq+: Ne7+ Ne8+ Nq+: N6+ N7+ and Feq+ Siq+ Mgq+ …. (q = 6 - 16) Ion velocity: ~ 300 – 1000 km/s slowfast solar wind

  14. Total EUV and X-ray Emission SpectraTotal Spectra =S i (Spectra of Individual SW Ions)

  15. P(hn) P(hn) – number of photons per SW ion [eV-1]

  16. Ne*8+

  17. Sensitivity of EUV and X-ray spectra to the ion velocity V :collisions :C6+ + H R1 : R2 = Function[v] R2 R1 X-ray EUV

  18. Spectra of CX Emission Induced by the Slow Solar Wind from H and He gas

  19. Emission from the Interstellar Hydrogen Gas(Heliospheric Ecliptic Plane)Pepino,Kharchenko, Dalgarno, Lallement (2004) H

  20. Brightness Distribution in the Heliospheric Ecliptic Plane H and He H He

  21. CONCLUSIONS • The CX mechanism successfully describes the observed spectra and intensities of the EUV and X-ray cometary emission. • The CX collisions of the SW ions with the interstellar H and He gas are an important local source the diffuse X-ray background. • Ion composition of the solar wind has been determined from the cometary X-ray emission spectra. • Relative intensities of the cascading emission lines provide unique information on the composition and velocities of heavy ions in astrophysical plasmas.

  22. X-ray Emission from the direction of the dark MoonB.Wargelin et al. (2004) Moon SW ion Sun Earth

  23. Spectra of X-Ray emission from two Comets McNaught-Hartley Linear S4 Lisse et al. (2001) Krasnopolsky (2004) Chandra X-ray telescope

  24. Theoretical Models for O8+ + H Emission Spectra of O*7+ Ions

  25. Emission Spectra ( Ion Beam Experiments ) O*6+

  26. X-ray emission spectra of Ne*9+ Slow collisions Ne10+ + Ne

  27. O6+ Emisson Beiersdorfer et al., Science (2003) O7+ + CO2 23S -11S 23,1P- 11S

  28. Laboratory Simulations of Cometary X-ray Spectra Beirsdorfer et al. Science, 2003

  29. Theoretical Models for O8+ + H Emission Spectra of O*7+ Ions

  30. Velocity Dependent Spectra of Cascading Emission of O*7+ Ions

  31. Theoretical and Experimental Spectra Ne10+ + H2O -> Ne*9+ + H2O+

  32. SW Velocity Diagnostic form EmissionSpectra of the Soft Cascading Photons

  33. O6+ Emisson Beiersdorfer et al., Science (2003) O7+ + CO2 23S -11S 23,1P- 11S

  34. Photon Emission Rate and Rate of Charge Transfer Collisions R Sun G= Collisional Depth =1 O8+ O6+ O7+ R O5+ SW Ions Example: O5+ G = 3 O5+ + H2O, H, O … Emission of O*4+ ions G = 2 O5+, O6+,O7+, and O8+

  35. 100eV G

  36. Heliospheric Emission :SW Ion Spectra from H and He gas

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