Department of Physics and Astronomy

Rice University

From the Omega facility to the Hubble Space Telescope:

Experiments and Observations of Supersonic Fluid Dynamics in Stellar Jets and Star Forming Regions

Patrick Hartigan LANL June 22, 2011

Omega Team

Experimental

J. Foster (AWE)B. Blue (GA)F. Hansen (GA)

Target Fabrication by General Atomics

Numerical

B. Wilde (LANL)M. Douglas (LANL)A. Frank (Rochester)P. Rosen (AWE)R. Coker (NASA/LANL)R. Williams (AWE)K. Yirak (Rochester/LANL)

R. Carver (Rice/LSU)J. Palmer (Rice)

Observational

Hartigan (Rice)

NASA HST/DOE NLUF2/34

1. Overview of Stellar Jets

2. Experiments at Omega

Talk Outline

Deflected JetsShock Waves and ClumpsIntersecting Shocks

3. Fluid Dynamics from HST Movies

3/34

4. Radiation Hydrodynamics in Star Formation

1. Overview of Stellar Jets

4/34

Burrows et al 1996

Reipurth et al 2001

5/34

Emission Lines give Doppler velocities, line ratios give temperature and density

Layer of Collisionally-excited H @ shock

Radiative Shock: One that cools by emitting photons that escapeRadiative Shock: One that cools by emitting photons that escape

Entire Cooling Zone is optically thin to optical and IR photons

6/34

Reipurth & Heathcote1992 A&A 257, 693

[SII] - Hα

Hartigan 1989 ApJ 339, 987

Bow Shock/Mach Disk Structures

Heathcote etal 1996

Reipurth NTT Image

HH 47

7/34

Internal Shock Velocities ~ 40 km/sBulk Flow Velocities 300 km/s

8/34

Hartigan and Morse 2007 ApJ 660, 426

9/34

10/34

Jet Collimation

11/34

What would we like to know?

• Anything about the magnetic field

• Connection between accretion and outflow

• Geometry of shock waves within the jet on small scales

• Feedback of the jets on their environments (entrainment, energy deposition, cloud destruction...)

• Effect of the environment on the jet (irradiation, deflection ...)

12/34

II. Clumpy Working Surfaces (analysis); III. Mach Stems (ongoing)

Experiments on Omega

I. Deflected Jets Hartigan et al. 2009 ApJ 705, 1073-1094

New IR ImagesNew High Resolution Spectra

New HST Images (3rd epoch!)Globule/Pillar Imaging

13/34

Deflected Jets: Project Strategy

Observations

Numerical Simulations

Experiments• Design a scaled experiment

• Decide which aspects are useful

• Test numerical codes

• What really happens?

• Essential for successful experimental design

• Use to step experiments in time to understand how the fluid dynamics produces structures we see in experiments

• Once we know the simulations match the observations, use them to generate radial velocity maps (spectra) to compare with observations

• Dynamics within deflected jets: high-resolution spectroscopic maps

• Entrainment: new infrared maps of molecular hydrogen

14/34

Deflected Jets: Experimental Design

15/34

Deflected Jets: Numerical Simulations

16/34

Experimental Results

17/34

Experimental Results

18/34

Fourier Analysis

DATA(4 regions)

EXPERIMENT

Green Region(Data + 3 sims)

Red Region(Data + 3 sims)

19/34

SCALING

Euler fluid eqns (mass, momentum energy) can be scaled (Ryutov et al 1999)

r = ar’ ρ= bρ’ P = cP’ t = a(sqrt(b/c)) t’

a~5x1016 b~2x10-20 c~3x10-19 100ns = 100yr

Jet: Eexp~6, Ejet~20

Bow: Mach numbers in both ~ 100Shock into Ball: Mach numbers in both ~100

Jet/Ambient Density ratio in exp is 1 - 8

Thermal diffusion, viscosity, radiative fluxes unimportant

Limitations• Jets are non-polytropic (cooling)• Jets have magnetic fields

20/34

Relevance of Experiment

Jet: Not relevant - magnetic aspect, no velocity variability, intrinsic shape are all wrong; velocities a bit low

Entrainment: Relevant - complex time-dependent, 3D structures; understanding of effect of impact parameter

Deflected Bow: Relevant - development of 3D structure within a working surface; understand orientation effects

21/34

Case Study: HH 110 Supersonic Wake from Deflected Jet

Reipurth, Raga & Heathcote 1996Riera et al. 2003

22/34

23/34

Longslit Spectroscopic Observations of the Deflected Jet HH 110

24/34

The Spectra ResolveThermal and NonthermalLine Broadening

25/34

Dynamics along deflected jet

26/34

Density in planes at z = 0, 0.02, 0.04 and 0.08 cm

27/34

18 28/34

What Do We Learn About Stellar Jets From These Experiments?

Single working surface can develop filamentary structure, but the velocity signatures are subsonic. Structure in HH 110 is supersonic, implying velocity perturbations at source

Be very aware of orientation

Entrainment can happen (3D) by a jet digging out a piece of an obstacle, accelerating it `gently’ as a clump

Shell structures in working surfaces produce arcs in position-velocity diagrams

29/34

Clumpy Jets: Experiments in Progress

HH 2

HH 1

30/34

Two Balls: Vorticity Deposition

31/34

Multiball (Douglas et al. in preparation)

Compare Shock Propagation Clumpy/Uniform Different Packing Fractions Mixtures of Large and Small Balls Images at Various Times Dual Axis Use Simulations to Understand Internal Velocity Structure

32/34

Intersecting Shocks: New Effort

HH 34

33/34

Mach Stems

34/34

Foster et al. 2010

Shock-reflecting cone embedded in foam

HST MOVIES

HH 34

HH 47

New Observations: Globule & Pillar Destruction

1/5

36/362/5

36/363/5

36/364/5

36/365/5