Laboratory Astrophysics with Chantal Stehlé

LERMA (Laboratoire d’Etudes de la Maère et du Rayonnement en Astrophysique et Atmosphères)

This work is partly supported by French state funds managed by the ANR within the Invesssements d'Avenir programme under reference ANR-11-IDEX-0004-02. astrophysics see for instance Savin et al. « Lab astro white paper », 2010

Perimeter Methods • Microscopic physical • Experiments processes (opacity, EOS) • Theory, databases • • Mulscale, mulphysics Numerical simulaons • Links to observaons processes (e.g. magnec reconnecon, shock waves, instabilies …) Tools • Study of large scale scaled • Medium size lab. processes, (e.g. stellar jets) experiments • Large scale facilies (lasers and pinches ) • Super-compung ressources OUTLINE

• Introducon • Stellar Opacity • EOS for gazeous planets • Scaling • Accreon & Ejecon processes in Young Stars • Conclusion Opacity for stellar interiors

From Turck Chièze et al. ApSS 2010 4 Opacity An example of opacity : For a optically thick medium, Hydrogen( Stehlé et al 1993) • LTE is ~ valid -> near blackbody radiaon κν/ρ

• The monochromac radiave flux Fν is proporonal to the gradient of rad. Energy

and to 1/κν (The radiaon tends to escape from regions

where κν is low, ie between lines) hν • The frequency averaged flux is

linked to the Rosseland opacity κR.

1 3 dν dB (T) / dT 16 σ T dT 1 ∫ κ ν < F > = and = ν d dB (T) / dT 3 κ R dz κ R ∫ ν ν 5 CEPHEIDS: the enigma

Strong periodic (P~ 1 – 50 days) Relaon P-L : variaons of luminosity L, Teff, and distance calibrator radius.

Enveloppe 2 The pulsaon (κ mechanism) log(κR in g/cm ) 2 • in the external part of the stellar envelope 1.5 • linked to an increase of the opacity 1 4 6 -7 -2 3 0.5 10 < T < 10 K (10 < ρ < 10 g/cm ) 0 Hence radiaon is blocked in the internal layers, -> heang -> expansion and beang Core 34 32 30 28 log(External Mass in g )

2 In the 90’, no code was able Temperature in K, κ in cm /g for M* = 5 M8, Y=0.25, Z=0.08, to reproduce the pulsaon. Teff= 6400 , 5900 and 5500 K (Bono et al 1999). 6 CEPHEIDS : theory and experiments

A synergec approach combining : Later on, results from the 1. A revised theorecal calculaon Opacity Project -> confirmaon of the opacity ( Baldnell et al. MNRAS 2005) (OPAL project, Iglesias et al. ApJ 1990)

2. A new calculaon of the stellar structure with the new opacies sets (Moskalik P. et all, ApJ 1992)

3. An experimental measurement of the Fe opacity (Da Silva et al 1992) Principle of an opacity measurement

T (hν) = exp (–kν ρ d)

Spectrometer : Transmission Difficules • TAMPER ( CH) Avoid the saturaon of the Sample spectra TAMPER ( CH) • Small temperature gradients (uniformity) • LTE Radiave heang X ray backlighng Revisited Cepheids opacies

Exp. Exp. + new calculation -> importance of the transitions Δn = 0 (Da Silva et al. PRL 1992) (neglected in the previous opacities).

OPAL Iglesias et al. ApJ 1990

Δn=0 -3 3 (3-3) Fe : 8 10 g/cm , 25 eV

New opacies introduced in the cepheid model.

-> A beer agreement between the observed and calculated pulsaon periods New opacies : was obtained 9 Differences for T > 105 K (bumps) (Moskalik P. et al, ApJ 1992 ) Current work on massive stars: 10-30 eV , 10-3 g/cm3

… smulated by asteroseismology space missions COROT, KEPLER, … PLATO .

Further experiments : e.g. on LULI 2000 going for Fe and Ni, in the condions of the enveloppes of these massive stars (Loisel et al. 2009, Blenski et al. 2011, Turck- Chièze et al. 2011)

Taken from Loisel PhD thesis, 2011

Increasing work on theorecal calculaons !! From Turck Chièze et al. ApSS 2010 What about the sun ? Like other stars, the sun oscillates. The heliosismologic observaons (SOHO ) allows to

compute the sound speed csound versus radius R. However: if one compares these csound “observed” values with the theorecal ones, using revised solar abundances (Asplund et al. ApJ 2005), Results with new opacies the disagreement for R /R¤ > 0.5, is larger than with the previous set of abundances (Grevesse & Sauval Sp.Sc.Rev. 1998)

(Basu & Ana 2008 , Bahcal et al. 2005, Turck-Chièze et al. 2011, Piau & Couvidat 2011) Results with old opacies A « lack » of opacity … ???

Differences between sound velocity between the solar models and the helioseismic results (Bahcall et al 2005) 11

The queson of the solar opacity in the radiave zone …..

in the radiave zone ( below 0.71 R⊙ ) 106 < T ~ <15 106 K, 1 <ρ <150 g/cm3

This requires high energy installaons !

21 -3 • Sandia ( Z ): Fe at T ~ 150 eV and Ne ~ 7 10 cm (Bailey et al. 2009) -> higher Fe opacity than predicted ! (Bailey et al , Nature 2015 ) 1.2 Opacity x 104 cm2 g-1 Comparison of Fe opacity : 6 0.8 Te = 2.11 10 K, 22 -3 Ne = 3.1 10 cm , 0.4 experimental in black (from Bailey et al., RSI 2015) 0 8 9 10 11 12 Å

• NIF : projects for C, N, O at T > 200 eV and ρ > 0.2 g/cm3 (Keiter et al. 2013) Equaon of state for planets

See also talk of K. Falk

Taken from hp://katjafalk.blogspot.fr/2011/10/my-dphil- research-project.html EOS for gaseous planets & exoplanets

P = P(ρ,T) (PV ≠ NkT at high pressure)

Mandatory to understand log T (K) the formaon, evoluon and 5 H+ structure 4 H atomic of planets and exoplanets.

3

For gaseous planets, H + He (10%) solid -> EOS of Hydrogen and He plays 2 a crucial role Log P(bar) Jupiter, 1 Complex: from molecular Saturn 2 4 6 8 to metallic state From Guillot, Ann. Rev. Earth& Plan. Sc. 2005 around 1 Mbar, 5000 K Jupiter See also talk of K. Falk Interior : a non ideal plasma • From molecular liquid to metallic H • H-He phase separaon (T < 5000 K, P ~few Mbar) 165 -170 K 1Mbar Molecular H2

Inhomogeneous ? 1) An outer helium-poor envelope 8300 -6800 K (He abundance constrained by 2 Mbar spectroscopic measurements of the atmosphere, GALILEO) Metallic H 2) An inner envelope, assumed to coincide with a metallic H region

3) A central dense core 15000 -21000 K of unknown mass and composion Rock- ice 40 Mbar core

15 From T. Guillot, Science, 1999 Sll large uncertaines EOS + observaonal constraints -> computaon of the internal structure

Mcore/Mplanet

Uncertainty concerning the mass of the core : even soluons with no solid core ( Mcore =0 ) do exist. -> impact on the formaon scenario.

Saumon & Guillot 2004 : « Improved astrophysical data will not be sufficient, however it is important to reduce the uncertaines surrounding the EOS of hydrogen in the 1 to 30 Mbar range ».

Similar situaon for Saturn MZ/Mplanet (Helled and Guillot, ApJ 2013) Jupiter structure: core and mass of heavy

16 elements: soluon fing the observaonal constraints for 5 H- EOS ( Saumon Guillot, ApJ 2004) EOS Experiments • Stac methods, e.g. diamond anvils (P < 1 Mbar, T < 10000 K) • Dynamic methods , e.g. lasers & pinches (P up to 100 Mbar, T up to 105 K) : generaon of a shock wave to compress the maer, determinaon of P, ρ, E, T. • A combinaon of the two

Derivaon of EOS based on Rankine Hugoniot equaons Pusher (u)

3 equaons linking the post shock u, P, (u0=0), P0, quanes (u, P, ρ, E) , the velocity ρ, Ε ρ0, E0 of the shock D to the pre-shock condions D 3 Taking ρ0 = 1 g/cm , D ~ u = 1 km/s for P0 ~ 1 bar -> P ~ 100 Mbar

5 unknown parameters : u, P, ρ, E, D => 2 parameters to be measured .

17 experiments on EOS

Strong pressure generated by laser ablaon ablator Pusher which drives the pusher.

u, T, ρ u0=0 , Pusher : a metal foil and an thin layer of ablator T0, ρ0 on the top of it (ablaon -> rocket launch) D Different diagnoscs, for instance : • VISAR for the shock velocity (D) (Celliers et al RSI, 2001) • Opcal pyrometry (SOP) or the shock temperature (T) (Cauble et al., ApJS, 2000) • Transverse radiography (D and u) (Cauble et al., ApJS, 2000) • Reflecvity measurement ( transion to metallic state ) (Knudsen et al., Sc. 2015) • X-ray Thomson scaering (ne, te, Ti, Z) (Falk et al. PRE, 2013)

Difficules : • Uniformity and planarity of the shock -> (phase plate to smooth laser beam) • Staonarity • Control of the inial condions : no preheang

18 D2 EOS laser experiments

In 2000, work on cryogenic D2 by Cauble et al. (ApJS 127, 267, 2000) at at the high pressure , high temperature, insolator – metal transmission

NOVA drive beam Shock front 527 nm, 3 1014 W/cm2, few ns Interface

Pusher : Al + layer of CH (ablator)

Be window Time in ns Backlighng Radiography

0 100 200 300 400 500 Distance in microns

Pyrometry => T U , U 19 p s Design of the cryogenic cell to measure properes of the EOS of Extensive study, in theory and experiments

300

250

200

D / H 150 2 2 100 Pressure in GPa

Pressure in GPa 50

10 100 1000 3 4 5 6 0 2 3 4 5 6 Compression ρ/ρ0 Compression ρ/ρ0 Calculated Hugoniots for D starng with the 2 Principal Hugoniot of D2 and H2 : experiments inial density of 0.717 g/cm3 (OMEGA ) and a selecon of theorecal results (from Hicks et al.. PRB 2009) (from Loubeyre et al. PRB 2012) Too large uncertaines in the measurements to constraint the various theorecal models

20 Similaries and Scaling Aircra in a wind tunnel at ONERA

21 HH47 seen by HST Similaries (Esirkepov & Bulanov, 2012) or, how to make the bridge between astrophysics and experiments ? Absolute similarity : same equaons, same dimensionless quanes, and also scaled inial condions (rather difficult ) Approximate similarity : only basic parameters are reproduced (common situaon) JETS - configuraon simulaon: global geometry + some physical processes - process simulaon: local physical processes in astrophysical condions. EOS OPACITY Limited similarity (qualitave scaling) (common situaon) dimensionless quanes, which are small compared to unity SHOCKS should be small in the model (or vice versa), but not necessarily by the same order of magnitude. Absolute similarity (1/3) Ryutov et al. PoP 2001

For a perfect fluid (no viscosity, no diffusion, no radiave transport ..) : the system evoluon is fully determined : 1) By the Euler equaons and ideal MHD ∂ρ +∇.ρu = 0 Mass conservaon ∂t % ∂u ( 1 ρ' + u.∇u* = −∇P − B× ∇ × B Impulse conservaon & ∂t ) 4π ∂u + u.∇P = −γP ∇.u Energy conservaon , with P /( 1) ∂t ε = γ − ∂B = ∇ × u × B ∂ t ρ(t=0, r) € € 2) and by the inial condions : ρ(r)|0, u(r) |0 , P(r)|0 , B(r)|0

23 r Absolute similarity (2/3) Taking characteriscs length L*, density ρ*, pressure P*, the equaons remain unchanged with the following change of variables r ρ P t P * ρ * B r = , ρ = , P = , t = , u = u , B = L* ρ * P * L* ρ * P * P *

THUS

€ ∗ ρ/ρ ∗ ρ/ρ1 2 The two systems evolve in idencal way ( in dimensionless units) if

1) the inial condions are geometrically similar ∗ ∗ r/L1 r/L2

2) the following 2 dimensionless numbers ρ * are the same for the two systems. u * = inv = Eu P *

2 B * 3) β =Ptherm/Pmag ~ P* / B* = cte = inv 24 P *

€ Absolute similarity (3/3) Validity condions All transport mechanisms mes must be negligible in comparison with the hydrodynamical me scales, i.e.

L* P* / ρ* Re = >> 1 Reynolds number v

L* P* / ρ* Pe = >> 1 Peclet number χ

L* P* / ρ* ReM = >> 1 Magnetic Reynolds number DM

χ, ν, DM, thermal, viscous and magnec diffusion coefficients

25 Crédit NASA

Jets from Young Stars

HST @ NASA Carina nebula

HST @ NASA Classical T Tauri Stars young: age < 10 Myr PROTOSTAR low mass: 0.1 < M* < 1 M¤ “cold”: Teff ~ 4000 K, Magnec Accreon field Topology disk • Star JET • Accreon disk -7 • Bipolar jets (Mejec~ 10 M¤/yr )

• Magnec field connecng the star to the disk ( ~ 1 kG) • Accreon flows from the disk to the -8 star (Macc~ 10 M¤/an) Accreon columns Accreon & ejecon have an impact on the stellar evoluon and need to be well characterized Stellar jets

Propagaon Aer launching, the jets are propagang almost hydrodynamically. Knots are associated to shocks (intrinsic variability, interacon with ISM..)

Typical condions :

vjet = 100 – 500 km/s,

0.32 light years ~ 20000 AU Mach number =vjet / csound >> 1 Length 1017 cm, radius 1015 cm, Density contrast ( jet/ISM) > 1

Launching HH 111 Linked to the effect of the disk rotaon and the magnec field which is anchored in it Stellar jets Lebedev et al 2002

Hydrodynamical Propagaon

Several experiments, with lasers and Z pinches showing in parcular

• The effect of radiave cooling on the collimaon (Lebedev et al. ApJ 2002 at MAGPIE)

• The interacon with an ambiant medium (bow shock, see for instance Nicolai et al. APSS 2009 at PALS)

Nicolai et al APSS. 2009 Stellar jets

Launching scenario (Blandford et al. MNRAS, 1992)

Poloidal magnec field anchored in the rotang disc. The maer is magneto centrifugally accelerated into a wide angle conical wind; The magnec field lines become twisted and the toroidal component of B leads to self collimaon.

Experiments : Need of a magnec field -> Z pinches

0.32 light years ~ 20000 AU (Lebedev et al. MNRAS 2005, A. Ciardi et al, PoP 2007, Suzuki-Vidal et al. APSS 2009) 298ns

However, this launching scenario is insufficient to explain collimaon of the flow into a narrow jet-like

HH 111 form.

=> Experiments invesgang the poloidal collimaon, (Albertazzi et al. Science 2014, Pisarczuk Phys. Scripta 1994 ) Albertazzi et al., Science 2014 A poloidal collimaon of stellar jets Pulsed aer the launching phase ? (1/2) coils • Plasc target • Laser ( ELFIE @ LULI ) 0.5 ns, B 100 J, 1053 nm, 1012 W/cm2 ELFIE • Pulsed B : 0.2 MG, duraon 5 µs CH Diagnoscs : visible interferometry v ~ 100 km/s

1017 cm2

Simulaons -> T ~70 eV at the Ne dl ∫ posion of the -2 Convergence of the Integrated Ne (cm ) at oblique shock plasma, oblique shock 20 ns at ~3 mm Albertazzi et al., Science 2014 A poloidal collimaon of stellar jets aer the launching phase ? (2/2)

3D simulation of jet collimation in a young star system in a 5 mG axial magnetic field .

An isotropic wind of H from the combined star–disk system with a mass ejection rate of 10−8 M☉/year and velocity 200 km/s is embedded in an initially axial (z) magnetic field

X ray emission map Ideal MHD Approximate similarity Labo astro Dim. less numbers Labo Astro 15 r (cm) 1 10 Euler 1 - 8 10 – 22 ρ (g/cm3) 5 10-4 5 10-18 => 20 ns Alfven, Reynolds >>1 >>1 correspond B( Gauss) 2 105 10-2 Peclet >>1 >>1 to 6 yrs

Vjet (km/s) ~ 100 100-500 Albertazzi , PHD mansucript 2014

Conclusion : a « small » longitudinal field of few mG allow to collimate the flow. This also explains the observed stac X ray emission spot near the star (Güdel et al. AA 2010) From magnetospheric From Long et accreon in young al. 2011 stars to radiave shock waves From Long et al. 2011

From Orlando et al. 2013 Accreon to the star From Romanova The scenario • Maer channeled by B (500 -1000G) from the disk to the photosphere -> magnetospheric columns • Free fall velocity (200 -500 km/s) • Impact the atmosphere -> strong shock at ~1 MK

Accreon B stream

Corona Only indirect observaonnal signatures : 300-500 km/s n < 1010 cm-3 • X rays (shock at the atmosphere, Ardiroffi et al 2007) 107 K • Lines shied by Doppler (column, Ardila et al 2013) • Brillant spots (atmosphere, Dona et al 2010)

1 - 5 106K

Hot slab X rays

1010-1015 cm-3 Global simulaons (1/2)

B= 50 G B= 500 G 6 12 T in log scale 10 4 U= 500 km/s 8

cm) cm) 9 9 2 6

z(10 z(10 4

0 2

0 0 2 4 6 8 10 r(109cm) 0 2 4 6 8 10 r(109cm) Orlando et al,A&A 2014 Global simulaons of the column in its surrounding show that the magnec field strength and topology play a dramac role.

Open quesons 1) Accretion rate deduced from X ray: too low ( not enough X rays! ) 2) Quasi Periodic Oscillations seen in the simulations but not observed.

chromosphere 35

RADIATION ON

Te up to 30 eV, equal Temperature before and after the front Global simulaons (2/2)

Accreon shocks , with T ~ 1 MK, are strongly radiave

• Standard simulaons assume that the shock is opcally thin to radiaon

• Differences in the shock dynamics and structure when radiaon is included in the simulaon. Radiaon trapping may even suppress the oscillaons (de Sa, PHD thesis 2014)

Need of 1) Radiave hydrodynamics simulaons 2) a good knowledge of radiave shocks Radiave shocks Radiave shocks in short

Strong shocks (M>>1), Thin – Thin regime which are structured by radiaon T Opcally thin hν D Radiave T cooling

hν hν

Thick – Thick regime

Post shock Pre-shock T Pre-shock heang hν Opcally thick Strong Absorpon 2 Tshock ~ Dshock Radiave precursor 38 Two radiave regimes Michaut & al. Astrophys. Space Sci. 322, 2009 1. The flux-dominated regime : The radiaon flux - Frad - is non-negligible, compared with the flux of material energy : Frad > (Pth + ρε)D This is regime the most common regime, as it is accessible with kJ class lasers ( LULI, OMEGA, PALS), In Xenon, v < 150 km/s

2. The pressure dominated regime :

At very high T, the radiaon pressure - Prad - (which is a factor 1/c smaller than the radiaon flux), may exceed the material pressure Prad > Pth

Few experiments, were v > 200 km/s, are trying to reach this regime (Diziere et al APSS 2011 at GEKKO).

11ns front front

Shocked gas precursor

cold Te up to 30 eV, equal Temperature before and after the front

11ns

Shock front : large compression (~ 30 ) : caused by shock, ionisation & radiation

40 Calculations using MULTI 1D (Ramis et al. 1988) How to produce them ?

Similar to EOS experiments, but in low Pusher density gases ablator • Gases at low pressure ( < 1 bar), ρ ~ 10-2 - 10-3 g/cm3 2 High atomic weight, Tshock ~ 3 m D /(16 k) Reighard et al. ‘06

• ~ 1 ns laser, usually the visible • 1014 W/cm2 on the target (-> 50-150 km/s) • Piston with ablang material 2 Pistons 4 mm long on a shield channel Difficules . • Target manufacturing: piston, windows, control of gas leakage • If 1D, uniformity of the laser • Dense post shock (opaque to visible) Rad shock target for counter-propagang rad shock waves at PALS (Credit Stehlé) Some results 2002 @ LULI ( ~ 60 km/s) visible me resolved interferometry -> precursor : • Shock velocity • 2D effects in the precursor : In a similar regime at PALS : radiaon losses at the windows Gonzalez et al. LPB 2006 reduce the velocity of the precursor Stehlé et al. LPB 2010 (Fleury et al, LPB 2002, Bouquet et al PRL 2005)….

2009 @ Rochester ( ~150 km/s)

point source X ray imaging -> shock front In a similar regime at OMEGA • Radiaon from the front ablates the Reighard et al. PoP 2006, 2007 Drake et al. HEDP 2010 , 2011 tube walls (wall shock) Doss et al, HEDP 2010 • Perturbaons near the front shock. Visco et al. , PRL 2012 (Doss et al. 2009)

2012 and 2014 @ PALS ( ~ 50 km/s) XRL radiography @ 21 nm -> shock, post shock , precursor • Structures in the precursor -> need of good opacies • possible instabilies in the post shock (Stehlé et al. Opcs Comm. 2012, Chaulagain et al HEDP 2014) A test case for simulaons

Van der Holst, HEDP 2013 (V= 150 km/s) Cotelo et al, HEDP 2014 (V= 48 km/s) comparison to Doss et al. 2009 at OMEGA comparison to Chaulagain et al. 2014 at PALS 0 700 um

Material

Te(keV) Te(eV)

AMR CRASH-2D (radiaon diffusion) AMR ARWEN-2D (Discrete-ordinate radiaon 1bar, 3500 J at 0.35 um; t= 13 ns transport method ) Material and AMR levels : Xenon (black), Be ( blue) , polyimide (green) … 0.3 bar, 60 J at 1.315 um; t= 13 ns Te(keV) in logarithmic scale Material: Au (orange), CH (dark blue), Xe (blue) Te(eV) in linear scale

Gonzalez et al., A&A 2009 (V= 60 km/s) comparison to Gonzalez et al. LPB 2006, at PALS HERACLES-2D Eulerian, M1 model 0.2 bar, 200 J at 0.438 um; t= 50 ns, 40% reflecvity at the walls Te(eV) in linear scale, Xenon only.

43 Conclusions A lot of applicaons to astrophysics

• Star formaon (jets, accreon shocks), • stellar interiors ( EOS and opacity) , • planetary interiors ( EOS)

But also Review paper : • ISM (ionisaon fronts and instabilies), Remington et al. Rev. • Supernovae explosions and remnants ( nstabilies), Mod. Phys. 2006 • Compact objects( accreon on cataclysmic variables ), • Sun atmospheres (magnec reconnecon) ,

Topic mostly driven by ns high energy lasers

For high intensity lasers, open field of research : • Collision less shocks, Review paper : • High energy parcle beams interacon with plasmas, Ersikepov et al. EAS, 2012 • Generaon of ultra high magnec fields ( > 1 Ggauss), • Ultra fast (relavisc) shock waves, etc.