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Mass-loss from Evolved stars : High Spatial Resolution Studies. Olivier Chesneau, Observatoire de la Côte d’Azur Collaborators (many…): A rmando Domiciano Bruno Lopez Sebastian Wolf Farrok Vakili Florentin Millour Luc Dessart Arnaud Collioud Tijl Verhoelst
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Mass-loss from Evolved stars:High Spatial Resolution Studies Olivier Chesneau, Observatoire de la Côte d’Azur Collaborators (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...
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., 2006astro.ph1169: post-AGB • Abraham, P.; Mosoni, L.; Henning, Th. et al. 2006astro.ph2334: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.ph12560,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 tohot 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 withMIDI 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
Lamers et Cassinelli, 1999 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,
N Star flux and dust clumping 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
Rotation? Binarity? Complex evolution? The B[e] phenomenon(Lamers et al. 1998) Supergiants B[e] L*/Lsun > 104 Observations point towards asymmetrical stellar environments 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 = (10.10.7) + (2.60.4) (-8m) mas Axial ratio 2b/2a = 0.76 0.11 Position angle PA = 145° 6° 2a = (15.30.7) + (0.450.22) (-12m) mas Axial ratio 2b/2a = 0.80 0.10 Position angle PA = 143° 6°
VLTI/AMBER spectrum and visibilities Gaussian models: 2a = (3.40.2) + (1.990.24) (-2.2m) mas Axial ratio 2b/2a = 0.53 0.03 Position angle PA = 173° 9° Br 2a = 4.50.3 mas ; =1.8 0.2 10-3m
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 Dfluxcont=0.62 DfluxInt=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 …
MIDI ISO Massive AGB long pulsator OH26.5+0.6 Embedded object: mJ=17, mK=8, mN=-3! P=1559 days
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
HST NACO 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 Lagadec, E., Chesneau, O., Matsuura, M et al., 2006
CPD-56 dusty core: a compact source 8.7 mm deconvolved image (30% PAHs)
MIDI data on CPD-56°8032 CPD1 B=45.7 m PA = -5° CPD2 B=45.6 m PA = 5° CPD3 B=41.2 m PA = 51° N CPD2 CPD1 Résolution36 mas à 8 µm60 mas à 13.5 µm CPD3
Best geometrical model for CPD-56°8032 ? CPD1 B=45.7 m PA = -5° R = 72 +/- 3 mas(110 +/- 5 UA) N i = 29 +/- 5° CPD2 B=45.6 m PA = 5° E CPD3 B=41.2 m PA = 51° -15 +/- 5° Good model ???
Towards complex models [ Shakura & Sunyaev 1973 ; Wood et al. 2002, Wolf 2005 ] α = 2.0 h(100 UA)=10 UA β = 1.5 500AU 2000 AU
Best model 10 micron image Résolution : 13 mas par pixel SED fit based on carbon chemistry only
High-Resolution view of CPD-568032 10 mm image 8.7 mm 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, Brg 6.5-9 mas (overresolved) Dynamics in Brg, 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,