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Suivi De Franges Pour L'interférométrie Infrarouge Observation De Binaires

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Suivi De Franges Pour L'interférométrie Infrarouge Observation De Binaires Observation de binaires en interaction à très haute résolution angulaire Suivi de franges pour l’interférométrie infrarouge Soutenance de thèse Nicolas BLIND Directeurs de thèse Jean-Philippe BERGER Alain CHELLI 1 The need for very high angular resolution 2 The need for very high angular resolution 8 meters 50 mas 3 The need for very high angular resolution T Tauri star ~10 mas 8 meters 50 mas Stellar surface Interacting binary ~5 mas ~20 mas 4 The need for very high angular resolution Synthetizing a giant telescope by combining several telescopes → angular resolution x25 Baseline B 200 m 5 Interferometric observables φ phase V eiφ = TF(source)(B/λ) 1.0 V 0.5 visibility Normalized amplitude 0.0 −5 0 5 10 Baseline B opd [µm] Single telescope Spatial frequency B/ λ Interferometer Fringe pattern 6 Interferometric observables 1.0 5. 3T 10+7 2mas 0. Parametric0.5 Visibility Parametric modeling Spatial frequency East [m] modeling −5. 0.0 −5. 0. 5. 0. 2. 4. 6. 8. 10+7 10+7 Spatial frequency North [m] Spatial frequencies 3T 7 Interferometric observables 1.0 4. 10+7 4T 2. 2mas 0. Parametric0.5 Parametric Visibility −2. modeling Spatial frequency East [m] modeling −4. 0.0 0. 2. 4. 6. 8. −4. −2. 0. 2. 4. 10+7 10+7 Spatial frequency North [m] Spatial frequencies 4T 8 Interferometric observables 1.0 1.0 10+8 0.5 2mas 0.0 0.5 Parametric Visibility −0.5 Spatial frequency East [m] modeling −1.0 0.0 −1.0 −0.5 0.0 0.5 1.0 0. 2. 4. 6. 8. 10+8 10+7 Spatial frequency North [m] Spatial frequencies 6T 9 Interferometric observables 1.0 1.0 10+8 iφ 0.5 V e = TF(objet)(B/λ) 2mas 0.0 0.5 Visibility −0.5 Spatial frequency East [m] −1.0 0.0 −1.0 −0.5 0.0 0.5 1.0 0. 2. 4. 6. 8. 10+8 10+7 Spatial frequency North [m] Spatial frequencies 107 Interferometric observables 1.0 1.0 10+8 iφ 0.5 V e = TF(source)(B/λ) 2mas 0.0 0.5 Visibility −0.5 Spatial frequency East [m] −1.0 0.0 −1.0 −0.5 0.0 0.5 1.0 0. 2. 4. 6. 8. 10+8 10+7 Spatial frequency North [m] Spatial frequencies Image Parametric reconstruction modeling T Leporis: Mira star Altair: Fast rotator Interference fringes 10 mas 2 mas Lebouquin et al A&A 2009 Monnier et al. Science 2007 117 Presentation outline An introduction to interferometry PART I. Study of interacting binaries • Interest of interacting binaries • The promises of interferometry • The case of SS Leporis PART II. Fringe trackers for imaging instruments Conclusions and perspectives 12 Why to study interacting binaries? At least 50% of stars are binaries Determining mass Constraints on stellar evolution models 13 Why to study interacting binaries? Interacting binary: 2 stars exchanging matter + complex structures (accretion disk, jets, nebula, etc.) Properties relevant to Excellent laboratories to study many astrophysical objects numerous physical processes Evolution dominated by mass transfer processes 14 Mass transfer processes Evolution dominated by mass transfer processes Roche lobe Stellar wind accretion Roche lobe overflow (RLOF) 15 Mass transfer processes Evolution dominated by mass transfer processes Roche lobe Stellar wind accretion Roche lobe overflow (RLOF) 16 Mass transfer processes Evolution dominated by mass transfer processes Roche lobe Stellar wind accretion Roche lobe overflow (RLOF) 17 Issues with indirect observables Spectroscopy or Photometry → Indirect observables → Assumptions required Can lead to conflicting observations, e.g.: Difference by a factor of 2 between stellar radii derived from Light Curve & Rotationnal Velocities Mikolajewska, Baltic Astro, 2007 Radii from RV Radii from rotationnalRadii from velocities LC 18 The breakthrough of interferometry Spectroscopy or Photometry → Indirect observables ~ 1 mas → Assumptions required < 1 AU Optical interferometry → Direct observables β Lyr (Zhao et al. 2008) Constraints on physical sizes, Image Model morphology High benefits from 1 mas new imaging capability Accretion disk Distorted giant 19 The case of SS Leporis M giant + oversized A dwarf + dusty disk SED Algol paradox Mass ratio MA/MM~ 2 to 4 → hints for mass transfer Roche lobe overflow Distance ~ 270 to 370 pc A star Envelope evolved M star Orbit: - P = 260d - Quasi circular A star - Inclination estimated to 30°±10° - Separation ??? ??? ~12 mas circumbinary material Verhoelst et al. 2007, Welty et al. 1995, Jura et al. 2001 20 VLTI observations 8 observations over 3 revolutions: • 4 AMBER (3T), H&K, R~40 • 4 PIONIER (4T), H, R~40 Method: 1. Images with PIONIER 2. Parametric modeling: morphology, orbit & energy balance Fundamental parameters (M, T) Constraints on the mass transfer 21 VLTI observations PIONIER images: SS Lep as a visual binary @ 3 epochs Commissionning data: resolution ~1mas Thanks to 4T, image reconstructions in <4h hours with MIRA (Thiebaut SPIE 2008) → with AMBER (3T) several nights required... 1st images of an interacting binary & orbital motion @ VLTI 28−10−2010 07−12−2010 22−12−2010 5 50 ] 1 − rad 0 6 ~5mas V [10 −50 > A star −50 0 50 M giant −−− U [106 rad−1] 0 N (mas) ~2mas −5 −5 0 5 −5 0 5 −5 0 5 E (mas) −−−> E (mas) −−−> E (mas) −−−> 22 VLTI observations Parametric modeling Resolved M star + unresolved A star + circumbinary material Free parameters: • Binary separation & orientation • M giant diameter (Uniform disk) • Dusty envelope size (gaussian shape) + Wavelength dependency of parameters: color Starting point: PIONIER images Envelope (~12mas) Binary (~5mas) M giant (~2mas) 1.0 50 PIONIER UV plan Visibility 50 ] 1 − rad 0 2 6 0.5 V 0 V [10 Phase closure −50 + Data - Model Closure Phase −50 0 50 0.0 −50 0 10 20 30 40 1.60 1.65 1.70 1.75 1.80 U [106 rad−1] B/λ λ 23 The energy balance Individual spectroscopy of the 3 components at a 1-mas resolution 5 M star MARCS model 2MASS photometry 3200±200K 2 Metallicity? M star ] 2 −10 − 10 [W.m A star Rayleigh-Jeans, 9000K (SED) λ F 5 10x oversized (∅~18R⊙) ? λ Envelope OR accretion disk ? 2 A star Envelope BB@1700K, gaussian 10−11 FWHM ~8mas 1.6 1.8 2.0 2.2 2.4 λ [microns] Sharper analysis: need for a high resolution spectrum 24 The orbit and masses Radial velocity + astrometry 4 PIONIER: unambiguous a ~ 1.3 AU positions 2 > −−− 0 AMBER: good orbit sampling N (mas) −2 −4 i ~ 37° −4−2 0 2 4 E (mas) −−−> Before Now d [pc] 330±70 280±25 (Hipparcos) MA [M⊙] 2~3 2.7 ± 0.3 MM [M⊙] 0.35~1 1.3 ± 0.3 MA/MM 4±1 2.2 ± 0.3 Errors dominated by the distance uncertainty 25 Mass transfer: stellar wind accretion! Before Now ∅M [mas] 3.1 ± 0.3 2.2 ± 0.01 d [pc] 330±70 280±25 ∅M [R⊙] 220±60 130±7 Roche lobe filling 140±20 % 85±3 % Errors dominated by the distance uncertainty No Roche Α lobe overflow Μ Stellar wind a ~ 1.3 AU accretion 26 A new vision of SS Lep Coll. H. BOFFIN Scenario for the accretion process Ideal candidate to test theories of accretion & mass loss Enhanced mass loss ~10-6 M⊙/year (Tout & Eggleton 1988) Wind accretion efficiency >> 10% (Nagae et al. 2004) <1mas Accretion disk 27 Perspectives for SS Lep New vision of the system, important constraints on the mass transfer Related publications and communications: • Conf Evolution of compact binaries (03/2011) • Conf 10 years VLTI (10/2011) • Publi. Blind et al. A&A accepted • Press release ESO (30/11/2011), A&A Future work on SS Lep: • Circumbinary envelope morphology → NaCo/SAM + PIONIER • Tidal distortion of the M giant ? → PIONIER • Accretion disk or oversized star? → VEGA/CHARA + simultaneous spectro/photometry 10/2011 - SS Lep observed with VEGA-3T «P Cygni» Hα line spatially & spectrally resolved 28 How to go further ? To do more physics, we need: • More objects: Increasing limiting magnitude • Spectro-imaging: More telescopes + spectral resolution Increasing sensitivity of the observations Need for a multi-telescope fringe tracker 29 Presentation outline An introduction to interferometry PART I. Study of interacting binaries PART II. Fringe trackers for imaging instruments • Context • Definition of a fringe tracker concept • The POPS concept Conclusions and perspectives 30 Dealing with the atmosphere... Turbulence Integration time < 10 ms → low sensitivity 31 ... by using a fringe tracker Fringe tracking: measuring and compensating in real time the randomly variing fringe position → sensitivity x1000 Turbulence Fringe tracker OFF Fringe tracker ON Integration time ~10ms Integration time ~5s ! Faint emission line SPECTROSCOPY ! 32 Fringe tracking at VLTI today FINITO PRIMA-FSU 3T - 2 baselines 2T Temporal fringe sampling Static fringe sampling Off-axis tracking Lebouquin et al SPIE 2008 Sahlmann et al A&A 2009 Performances FINITO + ATs PRIMA + ATs PRIMA + UTs Fringe tracking 5.5 ~ 8 9 Mag limit: H=5.5 @ ATs Fringe detection - ~ 10 11.7 33 A fringe tracker at VLTI tomorrow... More telescopes → increasing complexity 2T 2T → 1 baseline 3T → 3 baselines 4T → 6 baselines 6T → 15 baselines ... 34 A fringe tracker at VLTI tomorrow... More telescopes → increasing complexity 3T 2T → 1 baseline 3T → 3 baselines 4T → 6 baselines 6T → 15 baselines ... 35 A fringe tracker at VLTI tomorrow... More telescopes → increasing complexity 4T 2T → 1 baseline 3T → 3 baselines 4T → 6 baselines 6T → 15 baselines ... 36 A fringe tracker at VLTI tomorrow... More telescopes → increasing complexity 6T 2T → 1 baseline 3T → 3 baselines 4T → 6 baselines 6T → 15 baselines ... 37 A fringe tracker at VLTI tomorrow..
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