Mass-loss from Evolved stars:High Spatial Resolution Studies

Olivier Chesneau,

Observatoire de la Côte d’AzurCollaborators (many…):Armando Domiciano Bruno Lopez Sebastian Wolf Farrok Vakili

Florentin Millour Luc Dessart Arnaud Collioud Tijl Verhoelst

Romain Petrov Orsola De Marco Mikako Matsuura Eric Lagadec

Daniel Bonneau Albert Zijltra Michael Min Christain Hummel ...

VLTI: short technical description• VLTI+MIDI • 37 optical elements (33

reflections) • Until 200m baseline (and

350m of optical path!)• Automatisation: Active

optics (M1), chopping (M2), adaptive optics, moving delay lines, Variable curvature mirrors...

Preset

VINCI: K band test interferometer,

• No spectral dispersion,• Strong point: measurement accuracy (1% and less),

• Main science objective: measurement of stellar radii• Objects studied:

• Main sequence stars:• Kervella, P., Thévenin, F., Ségransan, D., et al. 2003, A&A, 404, 1087• Kervella, P., Thévenin, F., Morel, P., Bordé, P., & Di Folco, E., 2003, A&A, 408, 681• Kervella, P., Thévenin, F., Morel, P., et al., 2004, A&A, 413, 251• Kervella, P., Thévenin, F., & Di Folco, E. 2004, A&A, 426, 297• Di Folco, E., Thévenin, F., Kervella, P., et al. 2004, A&A, 426, 601• F. Thévenin, P. Kervella, B. Pichon, P. Morel, E. Di Folco, & Y. Lebreton, 2005, accepté

• Cépheids:• Kervella, P., Nardetto, N., Bersier, D., Mourard, D., et al., 2004, A&A, 416, 941,• Kervella, P., Bersier, D., Mourard, D., et al. 2004, A&A, 428, 587 ET 2004, A&A, 423, 327• Kervella, P., Fouqué, P., Storm, J., et al. 2004, ApJ, 604, L113

• Fast rotators:• Domiciano de Souza, A., Kervella, P., Jankov, S., et al. 2003, A&A, 407, L47• Kervella & Domiciano de Souza, 2006 accepted

• Eta Car: van Boeckel, Kervella, Schöller et al., 2003, A&A, 410, L37

MIDI: N band interferometer (8-13 micron)

• Spectral dispersion, 30 et 230, accuracy 5-15%, 2 telescopes• First interferometer of this kind (but see Keck),

• Main science goal: study of compact dusty objects• Spectral types: any with dust…

• Young stars disk (all types), evolved stars (all types),…• van Boekel, R.; Min, M.; Leinert, Ch. et al., 2004, Nature, 432, 479: Herbig AeBe stars• Leinert, Ch.; van Boekel, R.; Waters, L.B.F.M.; Chesneau, O. et al., 2004, A&A, 423, 537• Chesneau, O.; Meilland, A.; Rivinius, T.; Stee, P. et al., 2005, : Be star• Chesneau, O.; Verhoelst, T.; Lopez, B. et al., 2005, accepté, AGB,• Chesneau, O.; Min, M.; Herbst, T.et al., 2005, accepté, Eta Carinae, supergiant• Ohnaka, J.; Bergeat, T.; Driebe et al., 2005, A&A, 429, 1057 : AGB• Ohnaka, J.; Driebe, T.; Hofmann, K. et al., 2006, A&A 445 , 1015 : AGB• Derroo,  P.; Van Winckel, H.; Min, M. et al., 2006 astro.ph 1169: post-AGB• Abraham, P.; Mosoni, L.; Henning, Th. et al. 2006 astro.ph 2334: FU Or object

• AGNs disks,• Jaffe, W.; Meisenheimer, K.; Röttgering, H. J. A. et al., 2004, Nature, 429, 47, NGC1068• Poncelet, A.; Perrin, G.; Sol, H., 2006, A&A, accepted, astro.ph 12560, NGC1068

• 6 AGNS, 5 WR with dust, ~10 AGBs, 3 planetary nebulae, ~20 HaeBe, TTauri, massive young stars to come…

AMBER: J(1.2m), H(1.6m) and K (2.2m) interferometer• Strong points:

• spectral dispersion (1000,10000), • 3 télescopes recombinaison,

• Multiple science goals: potential far from being explored• Objects and phenomena studied:

• Main sequence: diameters, flattening and distortion, • Young stars: disk-photosphere interface, cinematic, jets, material exchanges…• Evolved stars: mass loss, molecular envelops, magnetism…• AGNs: accretion disks, jets…• Extrasolar planets: study limited to hot Jupiter ‘s,

• Several papers accepted or submitted:• Wind-disk interface study of the Herbig AeBe MWC297 (Malbet et al., accepted)• Dusty environment of the B[e] supergiant CPD-57 with MIDI et AMBER (Domiciano et al., accepted)• Study of the truncated disk of the Be star, alpha Ara (Meillant, Stee et al., accepted),• Study of the binary WR+O, gamma Velorum, (Petrov, Millour, Chesneau, et al., submitted)

• 2003: • 6 papers (VINCI) versus 17 for the year,• MIDI commissioning

• 2004: • 15 VLTI papers (12 VINCI, 3 MIDI) versus 27,• Active concurrence!

• Keck interferometer (2 papers in 2004), • IOTA, PTI, et NPOI,

• AMBER commissioning,• 2005: 14 VLTI papers (9 VINCI, 5 MIDI),

• First CHARA papers (5),• Keck interferometer (5),• 30 papers published

Information from: http://olbin.jpl.nasa.gov/(Optical Long Baseline Interferometry News )

VLTI: science contribution

A complementary tool Adaptive Optics: NACO

Some typical numbers:

. L’ PSF FWHM: 100mas, strehl~60-75%, Dec: 50-60mas

. K resolution: 60mas, Strehl~20-40%,

. Dynamical range: 103-104

Mass loss from evolved stars: loss of spherical sphericityI- Massive stars (‘Hot’)

Lamers et Cassinelli, 1999

Associated issues:. Binarity,. Rotation,. X ray generation in radiative winds,. Supergiant eruptions and instabilities,. Supernovae Ib,c, II remanent geometry. Dust production from hot stars

. LBVs,

. B[e],

. WR of carbon type,

The tip of the iceberg!

Smith et al., 2002, 2003

Understanding the visibilities with simple geometric models

Star flux and dust clumping

N

E

N

The central starQuestion: what is the influence of the dust extinction on the inferred parameters of the model?

Chesneau, O., Min, M., Herbst, T. et al., 2005

The B[e] phenomenon(Lamers et al. 1998)

Zickgraf et al. (1985)Zickgraf et al. (1985)

Supergiants B[e] L*/Lsun > 104

Observations point Observations point towards asymmetrical towards asymmetrical stellar environmentsstellar environments

Rotation?

Binarity?

Complex evolution?

VLTI/MIDI spectrum and visibilities

Gaussian models:2a = (10.10.7) + (2.60.4) (-8m) masAxial ratio 2b/2a = 0.76 0.11Position angle PA = 145° 6°

2a = (15.30.7) + (0.450.22) (-12m) masAxial ratio 2b/2a = 0.80 0.10Position angle PA = 143° 6°

B[e] supergiant B[e] supergiant starstar

CPD-57° 2874CPD-57° 2874

Domiciano de Souza, Driebe, Domiciano de Souza, Driebe, Chesneau et al. 2006 A&AChesneau et al. 2006 A&A

(astro-ph/0510735)(astro-ph/0510735)

VLTI/AMBER spectrum and visibilities

Gaussian models:2a = (3.40.2) + (1.990.24) (-2.2m) masAxial ratio 2b/2a = 0.53 0.03Position angle PA = 173° 9°Br 2a = 4.50.3 mas ; =1.8 0.2 10-3 m

Measured sizes of CPD-57 2874

The close WR+O system: gamma2 Vel

P=78 days,spectroscopic parameters well constrainedWR almost as bright as the O star in KNo dust!

Can we resolve the WR star?

Not with baselines smaller than 100m in K band,Better in H and very good in J (He10830)

We therefore expect a ‘simple’ binary signal

O8III+WC8 starTeffWC8~60000KTeffO8III~30000K

fluxcont=0.62fluxInt=0.75

Distance to be revised?

Hipparcos:

258+41-31

AMBER:

367+42-37

Petrov, R., Millour, F., Chesneau, O., et al., 2006, submitted

To come: study of the wind-wind collision (with more data…) confirmation of distance (with much smaller error bars)

Mass loss from evolved stars: loss of spherical sphericityII- Evolved ‘small’ stars (‘cool’)

Associated issues:. Binarity, symbiotic systems,. Planetary nebulae geometry,. Galactic dust production,. Novae, supernovae Ia…

Massive AGB long pulsator OH26.5+0.6

MIDI

ISO

P=1559 days

Embedded object:mJ=17, mK=8, mN=-3!

Parameters ISO/Justannont (1996)model: Minimum

MIDI model: Maximum Suh 1990, 2002

Teff 2200 K 2000 K 2400 KR* 650 Rsol 1120 Rsol 1017 RsolRin 7.5 R* 20.7 R* 8.5 R*

Rout 8x1015 cm 8x1015 cmMass-loss 5.5x10-4Msol/yr 6.5x10-4Msol/yr 6.x10-5Msol/yr

Mass 8 solar mass 8 solar mass 1.4 solar mass

Chesneau, O., Verhoelst, T., Lopez, B., et al., 2005

Complex objects:. Many opacities ignored:

. Dusty opacities,

. Molecular opacities,. Non-spherical geometry (always?),. Slow temporal variability,

About 140h of Ats observations planned on OH/IR embedded sources! (PI: Driebe and Verhoelst)

CPD-56°8032 and Hen2-113

• Central Stars [ De Marco et al. 97 ]

– Late Wolf-Rayet [WC10]– Teff ~ 30000 K– L ~ 5000 Lo, dM/dt=8-40 10-7Mo/yr– Wind: 160- 225 km.s-1

• Nebula [ Waters et al. 98, Cohen et al. 02, De Marco et al. 02 ]

– Strong IR emission dust– Edge-on disk suspected for CPD-56°8032 (STIS/HST)– Strong PAH emission, together with crystalline silicates features– Double chemistry : C (central star, ‘hot’ disk) and O (‘cold’ disk ?)– Distance: ~1.5 kpc

Col: A. Collioud (OCA,Fr), E. Lagadec (OCA, Fr), O. De Marco (AMNH, USA), A. Zijlstra (UMIST, UK), S. Wolf (MPIA, Ger), A. Acker (Obs Strasb., Fr), G. Clayton (LSU,USA), B. Lopez (OCA,Fr)

HST NACO

NACO MIDI

Lagadec, E., Chesneau, O., Matsuura, M et al., 2006

L’M’

• Central source magnitude in L’ and M’ respectively 300 and 800 more luminous than any [WR] models!

• Central object resolved by NACO! FWHM~155mas

CPD-56 dusty core: a compact source

8.7 m deconvolved image (30% PAHs)

MIDI data on CPD-56°8032

CPD1CPD1

B=45.7 mPA = -5°

CPD2CPD2

B=45.6 mPA = 5°

CPD3CPD3

B=41.2 mPA = 51°

CPD1CPD1CPD2CPD2

CPD3CPD3

N

Résolution36 mas à 8 µm60 mas à 13.5 µm

Best geometrical model for CPD-56°8032 ?

N

-15 +/- 5°-15 +/- 5°

R = 72 +/- 3 masR = 72 +/- 3 mas(110 +/- 5 UA)(110 +/- 5 UA)

i = 29 +/- 5°i = 29 +/- 5°

E

CPD1CPD1

B=45.7 mPA = -5°

CPD2CPD2

B=45.6 mPA = 5°

CPD3CPD3

B=41.2 mPA = 51°

Good model ???

Towards complex models

MC3D Parameters

Density (2d disk)

with

α = 2.0 β = 1.5 ho = 0.01 R*

2

)(2

1exp),(

rh

z

r

Rzr

α

o

R

zhrh o)(

[ Shakura & Sunyaev 1973 ; Wood et al. 2002, Wolf 2005 ]

2000 AU

500AU

α = 2.0β = 1.5

h(100 UA)=10 UA

10 micron image

Résolution : 13 mas par pixel

Best model

SED fit based on carbon chemistry only

High-Resolution view of CPD-568032

10 m image

8.7 m image (30% PAHs)

Chesneau, O., Collioud, A., de Marco, O., et al., 2006, submitted

The connection between PNs/SNIa and symbiotic systems: recurrent novae

RS Oph is in outburst since the 13th of Feb. 2006

Last outburst: January 1985! Estimated distance: 600pc (1.5-2.3kpc…)

DDT proposal (O. Chesneau, C. Hummel, F. Millour, M. Vannier):AMBER data taken the 18th of Feb.

First data

Typical sizes: continuum 3.5-4.5mas, Br 6.5-9 mas (overresolved)Dynamics in Brcomplex…Object centro-symmetric in continuum (fireball)

Other objects: QX Pup (OH231.8+4.2)

Matsuura, M, Chesneau, O., Zijlstra, A et al., 2006, in preparation

HST optical HST NicmosNACO 2.12

NACO L’ band

MIDI spectrum MIDI correlated flux

Typical extensions:(Gaussian model)

Actual situation:. Papers are based on 2-6 visibility measurements only,

. UT time pressure,

. ATs commissioning in progress,

. Limiting magnitude problems (no fringe tracker…)

. Interesting science only with a coupling with classical techniques (polarimetry, spectroscopy, radio imaging…)

. The progress will be slow:. The VLTI is now almost crystallized,. We have to ‘learn and understand’ the VLTI

. Give access to broad community,

Success: Only interferometer worldwide offered in Open Time! . Pionnier in extragalactic studies, mid-IR regime and high spectral resolution,