Download MIDI: Premiers résultats

Mass-loss from Evolved stars:
High Spatial Resolution Studies
Olivier Chesneau,
Observatoire de la Côte d’Azur
Collaborators (many…):
Armando Domiciano
Florentin Millour
Romain Petrov
Daniel Bonneau
...
Bruno Lopez
Luc Dessart
Orsola De Marco
Albert Zijltra
Sebastian Wolf
Arnaud Collioud
Mikako Matsuura
Michael Min
Farrok Vakili
Tijl Verhoelst
Eric Lagadec
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(1.2m), H(1.6m) and K (2.2m) 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)
VLTI: science contribution
• 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 )
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 sphericity
I- Massive stars (‘Hot’)
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,
Lamers et Cassinelli, 1999
The tip of the iceberg!
Smith et al., 2002, 2003
Understanding the visibilities with
simple geometric models
Star flux and dust clumping
N
N
E
The central star
Question: 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)
Supergiants B[e]  L*/Lsun > 104
Observations point
towards asymmetrical
stellar environments

Rotation?
Binarity?
Complex evolution?
Zickgraf et al. (1985)
VLTI/MIDI spectrum and visibilities
Domiciano de Souza, Driebe,
Chesneau et al. 2006 A&A
(astro-ph/0510735)
B[e] supergiant
star
CPD-57° 2874
Gaussian models:
2a = (10.10.7) + (2.60.4) (-8m) mas
Axial ratio 2b/2a = 0.76 0.11
Position angle PA = 145°  6°
2a = (15.30.7) + (0.450.22) (-12m) mas
Axial ratio 2b/2a = 0.80 0.10
Position angle PA = 143°  6°
VLTI/AMBER spectrum and visibilities
Gaussian models:
2a = (3.40.2) + (1.990.24) (-2.2m) mas
Axial ratio 2b/2a = 0.53 0.03
Position angle PA = 173°  9°
Br  2a = 4.50.3 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 constrained
WR almost as bright as the O star in K
No 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 star
TeffWC8~60000K
TeffO8III~30000K
fluxcont=0.62
fluxInt=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 sphericity
II- 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
Parameters
Teff
R*
Rin
Rout
Mass-loss
Mass
ISO/Justannont (1996)
model: Minimum
2200 K
650 Rsol
7.5 R*
8x1015 cm
5.5x10-4Msol/yr
8 solar mass
MIDI model: Ma
2000 K
1120 Rsol
20.7 R*
8x1015 cm
6.5x10-4Msol
8 solar mas
Embedded object:
mJ=17, mK=8, mN=-3!
MIDI
P=1559 days
ISO
Parameters
Teff
R*
Rin
Rout
Mass-loss
Mass
ISO/Justannont (1996)
model: Minimum
2200 K
650 Rsol
7.5 R*
8x1015 cm
5.5x10-4Msol/yr
8 solar mass
MIDI model: Maximum
Suh 1990, 2002
2000 K
1120 Rsol
20.7 R*
8x1015 cm
6.5x10-4Msol/yr
8 solar mass
2400 K
1017 Rsol
8.5 R*
6.x10-5Msol/yr
1.4 solar mass
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)
Chesneau, O., Verhoelst, T., Lopez, B., et al., 2005
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
M’
L’
• Central source magnitude in L’ and M’
respectively 300 and 800 more luminous
than any [WR] models!
• Central object resolved by NACO!
FWHM~155mas
Lagadec, E., Chesneau, O., Matsuura, M et al., 2006
CPD-56 dusty core: a compact source
8.7 m deconvolved image (30% PAHs)
MIDI data on CPD-56°8032
CPD1
CPD2
B=45.7 m
PA = -5°
B=45.6 m
PA = 5°
CPD2 N CPD1
CPD3
CPD3
B=41.2 m
PA = 51°
Résolution
36 mas à 8 µm
60 mas à 13.5 µm
Best geometrical model for CPD-56°8032 ?
CPD1
R = 72 +/- 3 mas
(110 +/- 5 UA)
B=45.7 m
PA = -5°
N
CPD2
i = 29 +/- 5°
B=45.6 m
PA = 5°
E
CPD3
B=41.2 m
PA = 51°
-15 +/- 5°
Good model ???
Towards complex models
Density (2d disk)
MC3D Parameters
α
 1  z 2 
 R 
 
 (r , z )  o   exp  
r
2
h
(
r
)
 


 
with
α = 2.0
α = 2.0
2000
AU
β = 1.5
 z 

h( r )  ho 
 R 
β = 1.5
[ Shakura & Sunyaev 1973 ;
Wood et al. 2002, Wolf 2005 ]

ho = 0.01 R*
h(100 UA)=10 UA
500AU
Best model
10 micron image
SED fit based on carbon chemistry only
Résolution : 13 mas
par pixel
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 Br, complex…
Object centro-symmetric in continuum (fireball)
Other objects: QX Pup (OH231.8+4.2)
NACO 2.12
HST optical
HST Nicmos
NACO L’ band
Matsuura, M, Chesneau, O., Zijlstra, A et al., 2006, in preparation
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,