1. Liyi Gu (SRON) CHANDRA WORKSHOP 2015, CFA T. Raassen (SRON), J. Kaastra (SRON, Leiden) 1.X-ray from ion-neutral collision 2.Velocity-dependent cross section 3.Real data fitting: comet X-ray

2. Over Barrierv, qσ tot Resonancev, q, Nσ tot, n, l Rotation mixv, ql Z q+ + A Z* (q-1)+ (n,l,S) + A + Emission by radiative cascade

3. SWCX in comets geocoronal & heliospheric space Polar region of Jupiter North Polar Spur Wolf-Rayet stellar winds Supernova shock rims Starburst galaxies Cool core clusters

4. Single electron capture with atomic hydrogen target (corrected for helium) Assumptions Take all available cross section data σ(v, n, l, s) from literatures & databases Challenge: incompleteness esp. for n, l-population Derive the “scaling-law” v-dependent n and l distributions, apply to the missing ions Method

5. Resonance peak Velocity-dependent scaling law

6. n < n p n > n p Rotation of internuclear axis determines l peak l population evolves with v, n A new v, n(q)- dependent scheme + five basic weighting function

7. Triplet-to-Singlet Ratio (C5+ with H) Higher order processes (e.g., electron-electron interaction) Calculated in very few cases Significantly affect the G-ratio at ~500 km/s G-ratio Velocity (km/s) Nolte+2012 Black: s-resolved Red: statistical weight

8. Highly excited p state to ground state transition (e.g., strong He-δ line) No up-excitation: 2 3 S 1 -2 3 P 0,1,2 > 1 1 S 0 -2 3 P 1,2 (forbidden line) CX model : lines from radiative cascade up to n=16 Bodewits (2007)

9. OVIII Lyα OVIII Ly OVII He OVII Heα f i r NVII Lyα NVII Ly CVI Lyγ CVI Lyβ β γ δ ε β γ δ β γ δ f i r NeIX Heα NeX Lyα SiXII 5->2 SiXII 6 & 5->2 SiXII 6->2 Wavelength (Angstrom) 0.3 keV 500 km/s l-shell not fully implemented

10. CX fitting: 0.14 keV 290 km/s C/2000 WM1, XMM-RGS Slow wind: 0.12-0.14 keV ACE record: 280-350 km/s

11. Charge exchange creates forbidden-dominated and high shell-transition (e.g., He-δ, Ly-δ) spectra SPEX “CX” model: Velocity-, subshell- dependent cross sections Cascade complete up to n=16 Applicable to many objects for measuring ion composition, ionization temperature, even collision velocity CHANDRA WORKSHOP 2015, CFA