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High Contrast Imaging and The Disk/Planet Connection Glenn Schneider Steward Observatory, University of Arizona (NICMOS/IDT) Direct (Scattered Light) Imaging of Dusty Debris Observing scattered light from circumstellar debris has been observationally challenging because of the very high Star:Disk contrast ratios in such systems. Until very recently the large, and nearly edge-on disk around b Pictoris remained the only such disk imaged. Resolved imaging 1984 - B.A. Smith & R.J. Terrile 6" radius coronagraphic mask, Las Campanas (discovery image) b Pictoris spatial distribution of dust/debris. Asymmetries (radial & azimuthal): • May implicate low-mass perturbers (planets) from: Rings, Central Holes, Gaps, Clumps, Arcs, Arclets • Help Elucidate the scattering & physical properties of the grains. The HUBBLE Legacy Breaking the Low Contrast Paradigm QuickTime™ and a None decompressor are needed to see this picture. TODAY HST Provides a Unique Venue for High Contrast Imaging • Diffraction Limited Imaging in Optical/Near-IR •> 98% Strehl Ratios @ all ls Background Rejection • Highly STABLE PSF 1.6mm: ~10-6 pix-1 @ 1” 1.1mm: ~10-5 in 2”-3” annulus • Coronagraphy: NICMOS STIS, ACS HST is a stepping • Intra-Orbit stone for superField high contrast * Rotation imaging * NIR High Dynamic Range Sampling NICMOS/MA: Dmag=19.4 (6 x 4m) Background Rejection 109—1010 Planet-Building Timeline HST Vis/NIR Taurus, Ophiuchus star forming regions HST Vis/NIR High Contrast TW Hydrae Tucanae Hyades Assoc Pleiades Assoc a Persei 106 yr s Collapsing protostar forms protoplanetary disk Beyond HST Vis/UV Super-High Contrast 107 yr s 108 yr s Giant planets accrete gaseous atmospheres Rocky cores of giant planets form Era of heavy bombarment by comets Terrestrial planets form Primary Dust (≤ mm) Secondary Dust (≥mm) Locked to Gas Collisional erosion Clearing Timescales: P-R drag few 10 6 Rad. Pressure: ~ 104 Sun 109 yr s Current age of the Sun: 5x109 yrs . Clearing of inner solar system, formation of a Kuiper cometary belt? From: R. Webb Scientific Areas of Investigation Enabled With Today’s Capabilities on HST via PSF-Subtracted Coronagraphic Imaging Young Extra-Solar Planet* & Brown Dwarf Companions 1" Circumstellar Disks fdisk/f* > few x 10-3 at 1” q > 50 mas * < few x 106 yr at 1” Moving Beyond HST into the Super-High Contrast Regime Exosolar Planet Imaging & Spectroscopy: few x 106 Myr at 1” > 109 yr (solar age) at 1” Disk Imaging & Spectroscopy: fdisk/f* > few x 10-3 at 1” ≤ 10-6 at 1” q > 50 mas a few mas (sub-AU at 200pc) OPTICAL CONFIGURATIONS TECHNOLOGICAL CHALLENGES •Coronagraphy •Polarimetric Nulling •Nulling Interferometry •Wavefront Correction •Station-Keeping Occulters •Interferometric Arrays •Micro-Roughness of Optical Surfaces •Particulate/Contamination Control •Stray Light Management & Control •Pupil Apodization (and Shaping) •Metrological Tolerancing & Stability •Wavefront/Mirror Sensing & Control The Dusty Disk/Planet Connection Current theories of disk/planet evolution suggest a presumed epoch of planet-building via the formation and agglomerative growth of embryonic bodies, and the subsequent accretion of gaseous atmospheres onto hot giant planets, is attendant with a significant decline in the gas-to-dust ratios in the remnant protostellar environments. In this critical phase of newly formed (or forming) extra-solar planetary systems, posited from a few megayears to a few tens of megayears, the circumstellar environments become dominated by a second-generation population of dust containing larger grains arising from the collisional erosion of planetesimals. < 1Myr Proplyds in Orion QuickTime™ and a None decompressor are needed to see this picture. and… Substellar Objets to ~ 10 Mjup HH30 Obscured GM AUR Unembedded Coronagraph + PSF Subtraction Direct Image ~ 1— few Myr Radius (Pixels) from Hole Center 5 7 9 11 13 16 Coronagraphic Background Reduction 15 14 13 12 11 10 9 8 INTENSITY (AZIMUTHAL AVERAGE) 10 0 5 17 19 21 23 25 27 29 31 33 35 37 REDUCTION IN BACKGROUND FLUX FROM F160W PSF 10-1 Unocculted F160W PSF PSF + Coronagraph PSF + Coronagraph + Roll 10-2 1 pixel 10-3 10-4 Coronagraph + 10-5 7 6 15 10-6 0 Coronagraphic Hole PSF Subtraction Radius = 0.3" 0.075 0.15 0.225 0.3 0.375 0.45 0.525 0.6 0.675 0.75 0.825 0.9 0.975 1.05 ARCSECONDS 4 Averages, 1-Pixel Wide Annular Zones 3 Azimuthal (69:69, 208:209) and (77, 205) Glint Features Excluded 2 0.3 0.45 0.6 0.75 0.9 1.05 1.2 1.35 1.5 1.65 1.8 1.95 2.1 2.25 2.4 2.55 2.7 2.85 Radius (Arcsec) from Hole Center Planet-Building Timeline Taurus, Ophiuchus star forming regions 106 yr s Collapsing protostar forms protoplanetary disk HH 30 Planet-Building Timeline Taurus, Ophiuchus star forming regions 106 yr s QuickTime™ and a Sorenson Video decompressor are needed to see this picture. Collapsing protostar forms protoplanetary disk Rocky cores of giant planets form Planet-Building Timeline TW Hydrae Assoc Taurus, Ophiuchus star forming regions 107 yr s 106 yr s Giant planets accrete gaseous atmospheres Collapsing protostar forms protoplanetary disk 141569A Planet-Building Timeline Taurus, Ophiuchus star forming regions TW Hydrae Tucanae Hyades Assoc Pleiades Assoc a Persei 106 yr s Collapsing protostar forms protoplanetary disk 107 yr s 108 yr s Giant planets accrete gaseous atmospheres Rocky cores of giant planets form Era of heavy bombarment by comets Terrestrial planets form Primary Dust (≤ mm) Secondary Dust (≥mm) Locked to Gas Collisional erosion Sun 109 yr s Current age of the Sun: 5x109 yrs . Clearing of inner solar system, formation of a Kuiper cometary belt? Clearing Timescales: P-R drag few 10 6 Rad. Pressure: ~ 104 From: R. Webb Examples of Dusty Disks with Radial and Hemispheric Brightness Anisotropies and Complex Morphologies, Possibly Indicative of Dynamical Interactions with Unseen Planetary Mass Companions, Spatially Resolved and Imaged Around Young (< 10 Myr) Stars by HST. HR 4796A (A0V), ~ 8 Myr A 70AU radius ring, ~ 12 AU wide ring of very red material, exhibiting strong forward scattering and ansally asymmetric hemispheric flux densities. Examples of Dusty Disks with Radial and Hemispheric Brightness Anisotropies and Complex Morphologies, Possibly Indicative of Dynamical Interactions with Unseen Planetary Mass Companions, Spatially Resolved and Imaged Around Young (< 10 Myr) Stars by HST. HD 141569A (Herbig Ae/Be) ~ 5 Myr A 400AU radius disk, with a broad, partially filled asymmetric gap containing a “spiral” arclet. Examples of Dusty Disks with Radial and Hemispheric Brightness Anisotropies and Complex Morphologies, Possibly Indicative of Dynamical Interactions with Unseen Planetary Mass Companions, Spatially Resolved and Imaged Around Young (< 10 Myr) Stars by HST. TW Hya (K7) “Old” PMS Star Pole-on circularly symmetric disk with a break in its surface brightness profile at 120 AU (2”). Examples of Dusty Disks with Radial and Hemispheric Brightness Anisotropies and Complex Morphologies, Possibly Indicative of Dynamical Interactions with Unseen Planetary Mass Companions, Spatially Resolved and Imaged Around Young (< 10 Myr) Stars by HST. TW Hya (K7) “Old” PMS Star and, possibly, a radially and azimuthally confined arc-like depression. Pole-on circularly symmetric disk with a break in its surface brightness profile at 120 AU (2”). HR 4796A 1.1mm 0.58mm HR 4796A RING GEOMETRY (Least-Squares Isophotal Ellipse Fit) Ansal Separation (Peaks) = 2.107” ± 0.0045” Major Axis of BFE = 2.114” ± 0.0055" P.A. of Major Axis (E of N) = 27.06° ± 0.18° Major:Minor Axial Length = (3.9658 ± 0.034): 1 Inclination of Pole to LOS = 75.73° ± 0.12° Photocentric Offset from BFE(Y) = -0.0159" ± 0.0048" Photocentric Offset from BFE(X) = +0.0031" ± 0.0028" HR 4796A Circumstellar Debris Ring - WIDTH NE ANSA CROSS-SECTIONAL PROFILE 1.1 WIDTH AT NE ANSA FWHM: 12.3±0.7AU 8.7% Dring 1-e-1:* 17.7±10.1AU 0.9 0.8 Brightness (normalized to NE Ansa) Brightness (Normalized to NE Ansa) 1 NE ANSA CROSS-SECTIONAL PROFILE 1.1 1 0.7 12.5% Dring 0.9 0.8 0.6 0.7 0.197" 0.6 0.5 0.197" 0.5 Measured PSF point source FWHM ring 1-e-1 * 0.4 0.4 0.3 0.2 0.3 0.1 0 -1.6 -1.5 0.2 -1.4 -1.3 -1.2 -1.1 -1 -0.9 -0.8 -0.7 20% inner:outer fall-off asymmetry Distance (Arc Seconds) -1.5 -1.4 -1.3 -1.2 0.197” 0.070” 0.184” 0.265” -0.6 0.1 0 -1.6 = = = = -1.1 -1 -0.9 Distance (Arc Seconds) -0.8 -0.7 -0.6 RING GEOMETRY - Least-Squares Isophotal Ellipse Fit Ansal Separation (Peaks) = 2.107” ± 0.0045” Major Axis of BFE = 2.114” ± 0.0055" P.A. of Major Axis (E of N) = 27.06° ± 0.18° Major:Minor Axial Length = (3.9658 ± 0.034): 1 Inclination of Pole to LOS = 75.73° ± 0.12° Photocentric Offset from BFE(Y) = -0.0159" ± 0.0048" Photocentric Offset from BFE(X) = +0.0031" ± 0.0028" “FACE-ON” PROJECTION - With Flux Conservation Spatially Resolved Relative PHOTOMETRY of the Ring NW:SE Surface Brightness Anisotropy Front:Back Surface Brightness Anisotropy 170 160 NE % FRONT:BACK SW % FRONT:BACK MEAN FRONT:BACK 1 + 0.73*COS(theta) 150 140 130 120 110 100 6 5 4 3 2 1 0 0 (NE Front-Back) : SIGMA(Front/Back) (SW Front-Back) : SIGMA(Front/Back) (MEAN Front-Back) : SIGMA(Front/Back) 10 20 30 40 Angle from Major Axis (Degrees) 50 60 Broad Colors of the HR 4796A Debris Ring [50CCD]-[F110W]=0.55±0.09 [50CCD]-[F160W]=1.14 +0.20 -0.17 Intrinsically red grains •Consistent with collisionally evolved population of particle sizes > few microns •Not primordial ISM grains •Similar intrinsic colors to TNOs in our solar system [V]-[J]=+1.07* •Consistent with laboratory* irradiation experiments on a variety of organics to study reddening of D & P type asteroids with distance From Sun. *Barucci et al (1993); Andronico et al (1987) Planet-Building Timeline Taurus, Ophiuchus star forming regions TW Hydrae Tucanae Hyades Assoc Pleiades Assoc a Persei 106 yr s Collapsing protostar forms protoplanetary disk 107 yr s 108 yr s Giant planets accrete gaseous atmospheres Rocky cores of giant planets form Era of heavy bombarment by comets Terrestrial planets form Primary Dust (≤ mm) Secondary Dust (≥mm) Locked to Gas Collisional erosion Sun 109 yr s Current age of the Sun: 5x109 yrs . Clearing of inner solar system, formation of a Kuiper cometary belt? Clearing Timescales: P-R drag few 10 6 Rad. Pressure: ~ 104 From: R. Webb Cooling Curves for Substellar Objects 0 Evolution of M Dwarf Stars, Brown Dwarfs and Giant Planets (from Adam Burrows) -2 200M jup 80M jup sun Log 10L/Lsum -4 -6 14M jup -8 STARS (Hydrogen burning) BROWN DWARFS (Deuterium burning) JUPITER PLANETS -10 6 7 SATURN 8 Log10 Age (years) 9 10 CORONAGRAPHIC COMPANION DETECTION (Multiaccum) Imaging at two S/C orientations (in a single HST visability period). Background objects rotate about occulted Target. PSF structures and optical artifacts do not. TWA6. Two Integrations: Median of 3 Multiaccum Each D Roll = 30° D Time = 20 minutes H “companion” = 20.1 DH = 13.2, r=2.5” At r=2.5” background brightness is reduced by an ADDITIONAL factor of 50 over raw coronagraphic gain (of appx 4). Each independent image of TWA6“B” is S/N ~20 in difference frame. Above: Coronagraphic Images D Roll: 30° Left: Difference Image Same display dynamic range Imperfections in PSF-subtractions result in residuals expected from pure photon noise. Systematics: OTA “Breathing” Target Re-centration Coron. Edge Effects Mechanical Stability Detectability and Spatial Completeness (r,q) Dependence via Model PSF Implantation Observed Model* *TinyTim Nulled Implant 5.0 HST+NICMOS Optical Model - Krist Detectability: (r,q) Dependence via Model PSF Implantation . Photometric Efficacy & Statistical Significance 25 % Recovered Flux 20 16 12 8 4 Detectability: (1”,q) Dependence via Model PSF Implantation 2.0 1.0 0.0 1.0 Arc Seconds 2.0 PSF FWHM = 0.16" TWA6 Image Combination: S/NTWA6B = 35 NICMOS F160W 25 OCT 1998 Camera 2 (0.076"/pixel) Coronagraph (0.3" radius) Integration Time =1280s H-Band (F160W) Point-Source Detectability Limits Two-Roll Coronagraphic PSF Subtraction 22m Total Integration DH(5s) = 7.14 + 3.15r” - 0.286r” 2 {M&K Stars} .. .. 9 Photon Noise Dominated Read Noise Dominated 4 10 11 12 0 -2 -4 -4 -2 0 14 2 4 0.0 0.2 0.4 0.6 0.8 1.0 Normalized Intensity 7x7 Pixels 71% Ensquared Energy DH M ag n it ud e 13 2 H=6.9 5s 15 1s 16 0 1 2 3 4 5 6 Radius (Arc seconds) 7 8 9 10 2.0 1.0 0.0 1.0 Arc Seconds PSF FWHM = 0.16" 2.0 TWA 6A/B TW Hya Assn K7primary, D = 55pc Age = 10 Myr r=2.54”, 140AU DH =13.2 (LB/A)[H]=5 x10-6 Habs = 16.6 NICMOS F160W 25 OCT 1998 Implies: • Mass ~ 2Jupiter S/NTWA6B = 35 • Teff ~ 800K Camera 2 (0.076"/pixel) Coronagraph (0.3" radius) Integration Time =1280s IF Companion... Confirmation (or Rejection) by Common Proper Motion 2.0 1.0 0.0 1.0 Arc Seconds … possible via groundbased adaptive optics imaging with a sufficiently long temporal baseline. 2.0 PSF FWHM = 0.16" NICMOS F160W 25 OCT 1998 Camera 2 (0.076"/pixel) Coronagraph (0.3" radius) Integration Time =1280s Keck II + AO imaging. Courtosy of B.Macintosh, LLNL Anomaly or Bias? A Jovian Planet @ > 140 AU? • RV Surveys suggest ~ 5% MS *s have 0.8—8 Mjup companions @ d < 3AU from their primaries. • NOT Where Giant Planets are found in our own Solar System WHY ARE THEY THERE? Posited*: Mutual interactions within a disk can perturb one young planet to move into a < 1AU eccentric orbit (as inferred from RV surveys), and the other… Ejected (but bound) to very large separations, > 100AU Cannot be observationally tested with HST-like capabilities, requires “Super-High” contrast imaging. * e,g., Lin & Ida (ApJ, 1997); Boss (2001, IAU Symp 202) Inner Regions of Evolved Disks Cannot yet be probed in scattered light. Yet, as inferred from mid-IR: An inner tenuous component of warm zodi-like dust may be confined within a few AU of HR 4796A. 12–20mm thermal emission is contained completely within the large inner “hole” of HD 141569A. What evolutionary and dynamical interactions may be going on between unseen planets and unseen dust which will shape these systems? Requires “Super-High” contrast and resolution. HST Has Sampled Only the Low-Hanging Fruit in the Disk/Planet Orchard. 200M jup TWA6B ? 80M jup sun 10L/Lsum -4 Log GL 503.2B GL577B/C -2 HR 7329B CD -33° 7795B 0 -6 14M jup -8 STARS (Hydrogen burning) BROWN DWARFS (Deuterium burning) JUPITER PLANETS -10 6 7 SATURN 8 Log10 Age (years) 9 10 Anomaly or Bias? A Jovian Planet @ > 140 AU? • RV Surveys suggest ~ 5% MS *s have 0.8—8 Mjup companions @ d < 3AU from their primaries. • NOT Where Giant Planets are found in our own Solar System WHY ARE THEY THERE? Posited*: Mutual interactions within a disk can perturb one young planet to move into a < 1AU eccentric orbit (as inferred from RV surveys), and the other… Ejected (but bound) to very large separations, > 100AU * e,g., Lin & Ida (ApJ, 1997); Boss (2001, IAU Symp 202) UV/Optical imaging and spectroscopy of collisionally evolved circumstellar debris and co-orbital bodies will play a pivotal role in furthering our understanding of the formation and evolution of exosolar planetary systems. To study physical processes acting over sub-AU spatial scales and time scales comparable to the age of our solar system will require a 3—4 order of magnitude improvement in instrumental stray light rejection over the performance obtainable with HST. GLENN SCHNEIDER NICMOS Project Steward Observatory 933 N. Cherry Avenue University of Arizona Tucson, Arizona 85721 HUBBLE SPACE T ELESCOPE Phone: 520-621-5865 FAX: 520-621-1891 e-mail: [email protected] http://nicmosis.as.arizona.edu:8000/ Is it, or Isn’t It? • Undetected in NICMOS 0.9mm Followup Observation I-H > 3 • Marginally Detected in 6-Orbit Binned STIS G750L Spectrum • Colors Consistent with 2 Mjup, 10 Myr, “Hot” Giant Planet Instrument NICMOS/C2 NICMOS/C2 STIS/G750L STIS/G750L Band F160W F090M I extract R extract Bandpass 1.40—1.80 0.80—1.00 0.81—0.99 0.63—0.77 If NOT a hot young planet, it must be a Highly exotic object! Mag 20.1 >23.1 ~25.4 >27.2 Is it, or Isn’t It? • Undetected in NICMOS 0.9mm Followup Observation I-H > 3 • Marginally Detected in 6-Orbit Binned STIS G750L Spectrum • Colors Consistent with 2 Mjup, 10 Myr, “Hot” Giant Planet* ~25.4 >27.2 >23.1 Spectrum from A. Burrows 20.1 * Sudarsky et al., 2000 • Keck/AO Astrometric (PM) Follow-up Thus-Far Inconclusive Is it, or Isn’t It? A differential proper motion measure will be obtained with NICMOS. If common proper motions are confirmed we will request time for NICMOS grism spectrophotometry to obtain a near-IR spectrum. ~25.4 >27.2 >23.1 20.1