Near infrared, IFU spectroscopy of HH99

1. Near infrared, IFU spectroscopy of HH99 Teresa Gianninigiannini@oa-roma.inaf.it INAF-Osservatorio Astronomico di Roma

2. Accretion and ejection of material from the protostar Infalling Gas Bipolar Outflow Young Star The star forming process gravitational contraction molecular cores t = 104 – 105 yr accretion disc planetary system T Tauri star t > 107 yr Main sequence star t = 106 – 107 yr

3. HH111 infrared visual Bow wing Bow head JetVjet Vs Mach disc (reverse shock) Bow shape forward shock Protostellar Jets: observations HH34 Properties: Size: 0.1 - 10 pc Velocity: 50 - 500 km s-1 Density: 102 - 106 cm-3 Temperature: 102 - 104 K Mass loss: 10-5 - 10-8 M/yr Ionization fraction: 0.02 – 0.5

4. H2 Near-Infrared lines H2 ro-vibrational [FeII] fine structure • From line intensity ratios • and profiles: • Extinction • Temperature • Electron density • Ionization fraction • Velocity • Bow geometry C-shock H2 emission V=7 Ground electronic state J-shock ionic emission ionic emission Why is important to study bow-shocks? • direct interaction with the ISM: compression, heating, medium acceleration • irreversible chemical changes of gas composition (molecular dissociation, sublimation of ices, endothermic reactions, disruption of dust grains) • accumulated thermal energy irradiated through line emission

5. SINFONI data-cube Davis et al.,1999 1.7472 µm 1.7476 µm HH99: well known prototype of bow shock ! D~130 pc (RCra star forming region) 1.7492 µm 1.7480 µm 1.7478 µm 1.7484 µm 1.7482 µm 1.7490 µm 1.7474 µm 1.7470 µm 1.7468 µm 1.7466 µm 1.7464 µm 1.7462 µm 1.7457 µm 1.7455 µm 1.7447 µm 1.7449 µm 1.7486 µm 1.7451 µm 1.7488 µm 1.7453 µm First 2-D analysis of a bow-shock: observing HH99 with SINFONI • 2-D structure of the shock surface •  IFU spectroscopy well suited • SINFONI spectrograph • Spatial resolution ~250 mas; FoV=8x8 arcsec2 • IFU spectroscopy in J, H, K • Spectral resolution: 2000 (J), 3000 (H), 4000 (K)

6. H2 ro-vibrational transitions • Different morphology for low • (E  30000 K) and high (E  30000 K ) • excitation lines. C: [FeII] 1.64 µm D: [FeII] 1.75 µm Atomic transitions • Mainly [FeII] transitions (46 lines) • H, He recombination lines (8 and 2) and • [PII], [CoII], [TiII] transitions • The atomic lines are emitted at the bow • apex region E: H Paß 1.28 µm F: [PII] 1.18 µm Giannini, Calzoletti et al. 2008 • More than 170 observed lines (normally few lines are observed) A: H2 1-0 S(1) 2.12 µm B: H2 2-1 S(17) 1.76 µm The intensity maps show a clear bow-shape morphology

7. Temperature gradient from • ~2000 K up to ~ 6000 K • H2 emission ‘survives’ beyond • the maximum temperature • predicted by C-shocks (~3000 K) • N(H2) strongly decreases • toward the head (H2 dissociation) 103 K units Fast non-dissociative C-type shock for the molecular emission (also at the bow-head) H2 diagnostics: temperature map  modelling the molecular emission H2 critical density values are very low (102-103 cm-3) In the shocked gas the H2 ro-vibrational transitions are thermalized at the (kinetical) temperature T (LTE). with: gv,J = (2I +1) (2J+1) N: Column density Q: Partition function

8. Le Bourlot et al., 2002 2 Rdis • Rdis: cap radius beyond which H2 emission disappears : this happens at a certain point along the bow where vshock exceeds vdis, at which H2 dissociates. • From Rdis and D’ we measure Vdis = 70-90 km s-1 H2breakdownvelocity • vdis is a function of the • pre-shock density • model predictions : vdis up to: • 25km s-1(Kwan 1972) ; • 50 km s-1 (Smith, 1996) ; • 80 km s-1 (Le Bourlot, 2002) • vdis important parameter that regulates : • shock models • efficiency of the H2 collisional dissociation • fractional abundance H/H2 and chemical • reactions in the post-shock gas. The 1.644 m peak is shifted with respect to the intensity peak: geometrical effect due to the inclination of the paraboloid :  ~ 40-60 From the line profile  vb~ 115 km s-1 [FeII] at 1.644 µm Our result agrees with the maximum value of Le Bourlot model  Models to be revised? • D’ : projected distance between the intensity peak and the velocity peak

9. Gas-phase iron abundance  modelling the atomic emission Iron is normally locked onto dust grains: the observation of iron lines is a measure of the shock efficiency in disrupting dust grains and releasing metals in the gas phase. Comparison of the observed ratio: Iron fractional abundance map refractory element non-refractory element with the solar abundance ratio • P and Fe are assumed all single ionized • P and Fe lines lie nearby in wavelength, • have similar excitation energy, critical • density and first ionization potential • up to 70% of iron is in gas-phase (at the bow-head) . • According to models this implies: • partial disruption of the dust grains • vshock> 100 km s-1 • T 104 K [FeII]1.257µm line contours Dissociative J-type shock for the atomic emission at the bow head

10. Conclusions • First detailed analysis of the interaction region between a protostellar jet and the ISM • First multiline analysis  detailed map parameters  stringent observative constraints to shock models • The classical “C-shock” (wings) plus “J-shock” (head) scenario is just a first order approximation : • - “hot” H2 also at the bow head (C-shock to be revised) • - FeII also in the wings •  new input for bi-dimensional shock models • From kinematics  new method to evaluate geometry and inclination angle • First measurement of the H2 breakdown velocity  new input for astrochemical models Thanks!!

11. One-dimensional shock models: shock types J(Jump)-type shock: discontinuity in the physical properties on a planar surface J-shock TMAX~ 105 K • The ISM is permeated by magnetic field • Into the ISM ions and neutral are decoupled J-shock with 200 yr magnetic precursor J-shock with 900 yr magnetic precursor If Vs > Vn and Vs < Vims J-shock with Magnetic Precursor As the Magnetic Precursor grows, the J discontinuity becomes fainter, up to disappear C-shock TMAX~ 3-4·103 K C(Continuous)-type shock McCoey,2004

12. Intensity of an optically thin transition i j: H2 [FeII] In the observed field of view variations of Av up to 4 mag are recognized First of all: the extinction maps ! Observed intensity: If the transitions are originated from the same upper level, the line ratio is independent from the local physical conditions, being a function only of atomic parameters (Aij and νij) and extinction.

13. T = 2000K T = 15000K Te~18000 K Te<10000 K 103 cm-3 units ne is typically 2-4 103 cm-3 with a peak up to 6 103 cm-3 at the bow head Nisini et al, 2002 • Highly excited [FeII] lines observed for the first time: electron temperature estimate at the bow head. Fast J-type shock for the atomic emission [FeII] diagnostics: electron density map • ne from line ratios between lines with: • different critical density • similar excitation energy

14. Line profile compared with the instrumental profile From the line profiles  vshock~ 115 km s-1 2 Rdis The 1.644 m peak is shifted with respect to the intensity peak: geometrical effect due to the inclination of the paraboloid :  ~ 40-60 H2 at 2.122µm 2 Rdis • Rdis: cap radius beyond which H2 emission disappears : this happens at a certain point along the bow where vshock exceeds vdis, at which H2 dissociates. • D’ : projected distance between the intensity peak and the velocity peak • From Rdis and D’ we measure Vdis = 70-90 km s-1 [FeII] at 1.644 µm Bow kinematics and geometry

15. ncr = 7.2 104 cm-3 Diagnostics with [FeII] lines Most of prominent observed transitions are originate from the 4D term and have similar excitation energies (~104 K) They have different critical density (104105 cm-3) They are NOT suitable to diagnose the gas temperature The ratio with lines originated from the 4P term probes the electron temperature A measure of the FWZI of a high resolution [FeII] line profile provides a direct estimate of the shock velocity (Hartigan,1987) The ratio of these lines is sensitive to gas density variation FWZI Nisini,2002

16. Diagnostics with H2 lines In the shocked gas the H2 ro-vibrational levels are thermalized at the (kinetical) temperature T (LTE) with: gv,J = (2I +1) (2J+1) N: Column density Q: Partition function Electronic ground state J-shock Constraining shock models with Boltzmann diagrams • A pure C-shock predicts temperature up to 3000 K • A pure J-shock predicts temperature up to 500 K A J-type component is responsible for the emissions from higher excitation levels (Flower,1999) C-shock Temperature stratification NLTE • Departure from LTE (NLTE component): • Increase in Vs and n decreases the departure • Increase in B enhances the departure

17. Problema dei coefficienti di Einstein (A) delle transizioni [FeII] Esistono 3 determinazioni teoriche (due di Quinet et al. 1996 e una di Nussbaumer & Storey 1988) che differiscono più del 30%, il che comporta: ~ 3 mag di differenza nel calcolo di AV, di conseguenza un fattore ~ 3 nella stima delle intensità di righe a 1 µm, un fattore ~ 34 nella stima delle intensità di righe a 0.5 µm !!!! Per stimare i coefficienti di Einstein tramite osservazioni è necessaria una determinazione indipendente dell’estinzione, i.e. effettuata con rapporti di righe diverse dal [FeII] Dalle righe di ricombinazione dell’idrogeno: AV=1.8+/-1.9 mag Tale indeterminazione non permette una misura accurata dei coefficienti A Le determinazioni teoriche di A non riproducono i dati sperimentali Tale metodo dovrebbe essere applicato ad una sorgente di estinzione nota

18. One-dimensional Shock Models Shock = discontinuity in the physical properties of a fluid Shock  Vs > cs in the InterStellar Medium (ISM): cs ~ 10 km/s Rankine-Hugoniot Jump (J) Conditions for a strong (Vs >> cs), non-radiating (adiabatic) shock in a monatomic gas. Effects of magnetic field on a J-type shock Into the ISM ions and neutrals are decoupled Alfvén velocity If B=0 and vs > vn If B≠0 and vs > vn,ims Discontinuous Shock (J-type shock) If B ≠ 0 and vs < vims and vs > vn Magnetic Precursor If B < Bcrit J-shock with Magnetic Precursor ((C+J)-type shock) If B > Bcrit C-type shock (Draine, 1980)

19. Le Bourlot et al., 2002 Our result (vdis =80-90 km s-1) marginally agrees with the maximum value of Le Bourlot model, but would imply a very low pre-shock density  Models to be revised? We measure vdis between 70 and 90 km s-1 H2 dissociation inefficient process