Near IR Emission from Supernova Remnants

1. Near IR Emission from Supernova Remnants John Raymond Why do J and H come from a completely different region than K? Rho et al. IC 443 JHK

2. Supernova Remnants X-rays H I lines (faint) T > 106 K Until tcool ~ 15,000 yrs

3. Supernova Remnants X-rays Vs < 200 km/s Ram pressure = ρV2 = const Optical, IR

4. Shock Waves Convert Supersonic Motion to Subsonic (Frame of Shock) Compress and slow gas; Convert Kinetic Energy Thermal Energy T = 1.4x105 V1002 for ionized gas n1 = 4 n0, v1 = v0 / 4 (relative to shock front) Gas cools, becomes denser and slows down (relative to shock front) n  1/T, but Magnetic Field may stop compression Cool gas photoionized by radiation from upstream

5. Radiative Shock Wave ( J-Shock) Ionization, Balmer Line Filament (JJ Lee) Cooling Region H I lines [Fe II] Nonradiative Region Photoionized Region

6. Post-shock Density

7. J-Shock Blair et al. Strong Forbidden Lines; [Fe II] in Near IR Strong UV and Ionizing Radiation if V > 80 km/s Can produce weak H2 after cooling; Low T

8. 20 km/s J-shock Shock heats and compresses gas Produces Ly Molecules form when gas cools below 100 K Bergin et al. Log time (yrs)

9. C-Shock Molecular gas, low ionization Ions coupled to B field drift through neutrals Ion-neutral friction heats the gas. H2 excitation cools it. T cannot exceed ~3000 K Without destroying H2 Most of shock energy is Converted to H2 IR lines Requires low ionized fraction Jimenez-Serra et al.

10. J-shock with Magnetic Precursor When heating rate becomes too large or when H2 is destroyed, a J-shock forms. Resulting spectrum is a mixture of J- and C- shocks, [Fe II] and H2. This does not work if V is large enough to make ionizing photons. Flower et al.

11. H2 Boltzmann Diagram Gredel I(i,j) = N(j) Aji Relative populations of levels give temperature; exp(-E/kT) C-shock gives T ~ 2500 K

12. Multi-Temperature Case Need Mid-IR rotational lines Can indicate precursor or other excitation mechanism Fluorescence Cabrit et al.

13. Fluorescence by Ly HH 47; Curiel et al. Mira; Karovska et al.

14. Multiple H2 Temperatures Slopes of log(N) vs Energy Flower et al., HH 43

15. [Fe II] from J-Shocks, H2 from C-Shocks Oliva et al.; RCW 103 H2 filaments close to, but “ahead” of [Fe II] filaments

16. VERY different H2 and [Fe II] Line Widths Oliva et al.; RCW 103 H2 line is unresolved at 130 km/s (Fabry-Perot) [Fe II] hundreds of km/s wide C-Shocks and precursors < ~ 50 km/s

17. Why H and K are disjoint Oliva et al.

18. Another Example: Bullets in Orion Nebula AAT Image [Fe II] (green) from stronger shocks H2 (red) from weaker oblique shocks

19. High Resolution Spectra S. Park N49

20. High Resolution Spectra LMC Supernova Remnant N49 Long-slit Echelle Long-slit Echelle Shocked Gas Pre-shock Photoionized Gas Vancura N49

21. Near IR High Resolution: H2 H2 Line profiles C-shock vs J-shock C-shock intrinsically narrow (T < 3000 K), but shock curvature increases line width Study interaction of blastwave with cloud Dominates cooling, luminosity, evolution H2 Intensities T to discriminate C-shock, J-shock, Fluorescence, Formation HH Objects

22. Schwartz & Greene HH 47A Position-Velocity diagram; H2 Use with Bow Shock models to find shock parameters and flow Correia et al.

23. Near IR High Resolution: [Fe II] [Fe II] Intensities T, ne [Fe II] profiles shock vs. precursor velocity and curvature of shock post-shock turbulence Fe abundance? Velocity ellipse for extragalactic SNRs

24. Summary High resolution spectra of SNRs and HH Objects in H and K bands should mostly show H2 and [Fe II]. They generally come from different regions. They can be used to determine shock parameters and to study the interaction of the shock with dense clouds.