HH s at NIR Observations Diagnosis

1. HHsat NIR Observations Diagnosis

2. OMC 1 Outflow  t = 500 yr) Orión Nebula NKL Trapezium (L = 105 Lo t << 105 yr) (L = 105 Lo t < 105 yr) OMC1-S (L = 104 Lo , t < 105 yr) Infrared “continuum “line”

3. H2 1-0 S(1)

4. Gautier et al. (1976), ApJL, 209 L129: The spectrum of the infrared nebula Beckling-Neugebauer (BN) of Orión: From the analysis of H2 molecular gas at T~2000K

5. Nadeau&Geballe (1979), ApJL, 230 L169 Lines of H2 2.12mm show FWHM 20-60 kms-1 vg~40 kms-1 (and up to 100 kms-1)----->PROBLEM: Models found that shocks with v>25kms-1 disociate the H2 molecule (Kwan 1977 ApJ, 216, 713)

6. Schwartz et al. (1987), ApJ, 322,403 The first observations (low-resolution spectroscopy) showed that the low-excitation HHs had strong H2 emission The strongest H2 emission line is at 2.12mm Usually, the intesities of the Ha and H2 at2.12mm emission lines have similar strengths.

7. HHs in NIR Emission lines of H2 cooling of the shock in HHs  H2 emission clues on the physic in the low-velocity regime; “complementary” information from the one obtained from atomic line emission at optical wavelengths. Because its characteristic cooling time is shorter  H2 emission lines trace the regions where the jet/ambient interaction is more recent than the regions traced by optical lines ( younger jets). Also, we can trace the jet closer to the exciting source (as in Ha) HH emission lines at NIR: [FeII] (~1.64 mm) (H) H2 (~2.12 mm) (K)

8. Comparing optical/nir emission: I In few cases, the NIR “nebulosities” are the counterparts of HH wellkown jets. However the optical and nir emissions are not fully coincident (there is someshift). II Other NIR jets have not optical counterpart: The optical counterpart of a NIR jet is detected far from the source than the NIR jet. Optical and NIR emissions are tracing different physical conditions In general, is not possible to predict the NIR emission from the optical one.

9. Non-coincidence optical/NIR jets

10. Reipurth & Bally (2001), ARAA, 39, 403

11. Noriega-Crespo et al., 1996, ApJ, 462,804

12. Without optical counterpart

13. HH 212 Tedds et al. RmxAA 13,103 (2002)

14. HH 212 NH3 Wiseman, J. ApJ, 550, L87 (2001)

15. Narrow-band NIR images: [FeII] (1.644) y H2 (2.122) In general: *There is a complex relationship between the spatial distribution of both emissions. *At the bow-shocks: + [FeII] : brighter at the apex : (vs)n has its maximum +H2: brighter at the winds (vs)n lower.

16. Davis et al. 2000 MNRAS, 318, 747 Red: H2 green: [FeII]

19. Excitation mechanisms for H2 levels: • Fluorescence: pumping UV photons • Collisional excitation by shocks • Fluorescence: not clear evidence in HHs. • Collisional excitation: From intermediate-resolution HHs spectra  the obtained population distribution is consistent with a gas • T~ 2000-3000 K

22. H2 1-0 S(1)

23. H2 emission lines in H and K bands observed in stellar jets

24. IR DIAGNOSTIC

25. HH46-47 jet at 2.12 mm Source: Class I, in a phase of high accretion; binary system d~450pc; located at the border of a Bok globule. Atomic and molecular flows associated.

26. Continuum-subtracted spectra The presence of Brg emission near the source is signature of high excitation conditions in the region.

27. Spectrum for knot Z1 covering the J,H,K bands

28. Kinematics: velocities of the ionized ([FeII] and neutral (H2) emissions

29. Position-Velocity diagrams (Velocity, in LSR and corrected For a parental cloud velocity +20 km/s)

30. Radial velocitues computed by a Gaussian-fit to the line profile of each knot Blue and redshifted values, decreasing as the distance to the source increases Two velocity components in some knots.

31. Physical conditions

32. Temperature Using the H2 detected transitions  excitation diagrams: If collisional de-excitation is assumed to dominate, H2 population levelswill be in LTE Boltzmann distribution: Ni/Nj = gi/gj exp [-(Ei – Ej)/kTex] N: column density ~ F line Plot ln[N(n,J)/gn,J] vs E(n,J) linear fit slope ~ T-1 gn,J : statistical weight of a given (gn,J) ro-vibrational level E(n,J): Excitation energy

34. Ex: physical conditions HH 43 from NIR spectra Gredel, A&A,292,580 (1994) H K

35. T=2200K T= T=1900K The measured intensity, I(v,J) , of a given H2 line is used to calculate the column density, N(v,J), of the upper excitation level of the transition. For optically thin emission, I(v,J)=(h/4p) nA(v,J)N(v,J) Plot of ln(N(v,J) vs excitation energy E(v,J): Continuum: fit for T = 2200 K Dashed: Fit using the four lowest levels, T = 1900K

36. Temperature in a bow-shock (of HH99B) Giannini et al., 2008, A&A,481,123

37. Density

38. [FeII] NIR emission [FeII] shows a rich line spectrum in the J-K wavelength range (1.1-2.5 mm), very useful for the analysis of the ionized component in shocks produced in regions with high optical extinction.

40. *[FeII] as a tracer of ne : nc [Fe] >> nc [SII], [OII]  Use to derive ne in regions of ne > 104 cm-3 and/or with higher extinction. *As a tracer of T: Lines in the range 1.1-2.5 mm arise from a level with four sublevels ~ DE line ratios are weakly dependent on T  a good choice is to combine lines from another range ex: 8671 A + 1.64 mm • *To derive the reddening: • Lines in J and H windows, arising from the same sublevel: • The line ratio is sensitive to the reddening • (ex. 1.257 mm y 1.644 mm) Av • F 1.257/F 1.644 = 1.36x10-(EJ-H/2.5) • Av = 10xEJ-H

41. Ex: A combined optical/infrared spectral diagnostic of HH 1 (see Nisini et al. ,2005, A&A ,441, 159 for details).

43. Derived physical parameters along the HH 1 jet.