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Young Planets Embedded in Circumstellar Disks

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Young Planets Embedded in Circumstellar Disks Young planets embedded in circumstellar disks Sascha P. Quanz (ETH Zurich) Image credit: ESO/L. Calçada The National Centres of Competence in Research (NCCR) are a research instrument of the Swiss National Science Foundation Where, when and how do (gas giant) planets form? Gas giant planets are found over a broad range of separations From radial velocity surveys From direct imaging HR8799 HD95086 GJ 504 Marois et al 2010; Rameau et al. 2013a,b; Kuzuhara et al. 2013 The physical processes involved in planet formation are largely unconstrained Spiegel & Burrows 2012 (see also, e.g., Marley et al. 2007) Indirect signatures of planets thanks to high-spatial resolution imaging of disks Gaps in the HD169142 protoplanetary disks revealed by polarimetric imaging 7 (Sub-mm) interferometry NIR scattered light imaging Distance (AU) Distance (arcsec) −150 −100 −50 0 50 100 150 −1" −0.5" 0" 0.5" 1" N N a) b) 1" 150 150 1" E E 100 100 0.5" 0.5" 50 50 0" Dip 0 0 0" −50 Distance (AU) −50 Distance (arcsec) −0.5" −0.5" Distance (arcsec) −100 −100 AO feature −1" −150 −150 −1" −1" −0.5" 0" 0.5" 1" −150 −100 −50 0 50 100 150 Distance (arcsec) Distance (AU) −1" −0.5" 0" 0.5" 1" 1" The Astrophysical Journal LettersN,729:L17(6pp),2011March10 140 Hashimoto et al. c) d) 150 1" 120 E AU 0.8" 100 AO feature 150 100 50 0 -50 -100 100 50 0 -50 -100 -1500.5" 100 50 0 -50 -100 -150 100 50 1 0.5 0 -0.5 0.6"Ring gap A Outer ring 80 0 0" 0.4" 60 Distance (AU) −50 D Distance (AU) −0.5" Distance (arcsec) E 40 −100 0.2" B AO feature P1 AU −150 −1" 20 P3 Dip F 0" P2 0 −150 −100 −50 0 50 100 150 0 90 180 270 360 Distance (AU) Degrees eastG of north Dec. offset (arcsecond) Dec. offset N -0.5 0 0.5 1 2 Fig. 1.— NACO/PDI observations of HD169142 in the H band. a) Final Qr image scaled with r to compensate for the decrease in stellar flux (image shown in a linear stretch). The positionE of the centralInner star ring is indicated by the redC cross. Saturated pixels in the central regions have been masked out. Our data reveal a bright inner ring, a large gap and a smooth outer disk in polarized light. A brightness dip in the ring and a residual 0.5 AO feature 0 are indicated -0.5 by arrows. -1 b) Ur with 0.5 the same 0 scaling and-0.5 stretch as -1 for the Qr image. c) Intensity image also scaled with r2.FeaturesfromtheAOsystemandthetelescopespidersareclearlyseen.d)PolarcoordinatemappingofQ . R.A. offset (arcsecond) r Andrews et al. 2011; Hashimoto et al. 2011; 2012; The innermost, masked out region is less than 0.1′′ in diameter. The red line traces the peak brightness of the inner ring. Quanz et al. 2013b; Havenhaus et al. 2014; Garufi et al. 2013 10 (mJy/arcsec 2 ) 100 100 50 10 Total G F Surface brightness (mJy/arcsec ) D intensity 2 Polarized E intensity A P3 P2 P1 2 Surface brightness (mJy/arcsec ) C B 10 50 100 110 120 10 50 100 110 0 100 200 300 0 100 200 300 θ (degree) Figure 2. Magnified view of the inner PI images of AB Aur and their averaged azimuthal profiles. Top: magnified PI image with a coronagraphic occulting mask of 0′′. 3 diameter (left) and the features of the PI image (right). Central position (0, 0) is the stellar position. The outer and inner rings are denoted by the dashed ellipsoids. The solid ellipsoid indicates the wide ring gap. The dashed circles (A to G) represent small dips in the two rings. The filled diamond, circle, and square represent the geometric center of the inner ring, ring gap, and outer ring, respectively. The field of view in both images is 2. 0 2. 0. The solid circle in the left bottom inset ′′ × ′′ represents the spatial resolution of 0′′. 06. Bottom left: averaged azimuthal profiles of the outer ring for the PI (black) and reference PSF-subtracted I (red) images. The profile is averaged every 5◦ in position angle (corresponding to resolution) in the outer ring. Bottom right: same with the bottom left image, but for the inner ring with every 15◦ in position angle (corresponding to resolution) in the inner ring. (A color version of this figure is available in the online journal.) Our observations are consistent with Perrin et al. (2009). early phase of global evolution, and possibly one or more unseen When we assume that a companion is 100% polarized in planets are being formed in the disk. the PI image, which is the faintest case as Oppenheimer One possible explanation for the non-axisymmetric structures et al. (2008), the upper limits of its mass at 5σ (the absolute is GI of the disk (e.g., Durisen et al. 2007). If Toomre’s magnitude of 11.7 at the H band) of the photon noise in Dip Q-parameter (defined as Q csκ/πG!,wherecs, κ,and! = Aare5and6MJ for an age of 3 and 5 Myr, respectively are the sound speed, epicycle frequency, and surface density, (Baraffe et al. 2003). These derived upper limits of the respectively) is of the order of unity, GI occurs and a mode masses are consistent with that of 1 MJ inferred by the with a small number of arms is excited, that is, a pattern of the numerical simulations (Jang-Condell & Kuchner 2010). On surface density arises that may resemble what we have observed. the other hand, our upper limits for point sources in the dips However, this GI possibility may be rejected for AB Aur seen in the inner ring are 7 and 9 MJ for these ages due to (at present) because optically thin submillimeter observations higher photon noise. indicate that Toomre’s Q-parameter is of the order of 10 (Pietu´ et al. 2005). It may be noted that the disk mass estimate from The structures of AB Aur’s inner (22–120 AU) disk surface submillimeter emission has large uncertainties arising from the described above indicate that the disk is in an active and probably uncertainties in the optical properties of the dust particles. 4 3 systems with promising candidate planets in disks (at the moment) The planet candidate in the LkCa 15 disk SMA 850 micron + Keck aperture masking (2.3 and 3.8 micron) •Dust cavity R~40-50 AU (also in scattered light) •Companion candidate in the cavity at ~11 AU Kraus & Ireland 2012; Andrews et al. 2011; see also Thalmann et al. 2011, 2014, 2015 First attempts to detect the circumplanetary disk around LkCa 15 b VLA 7mm data Isella et al. 2014 –11– 0.8 VLA CnB VLA B 7 mm 7 mm 0.4 + + HD169142 - sequential0 planet formation? + + −0.4 1.6 micron scattered light image 7 mm(a) VLA data (b) −0.8 0.8 VLA CnB+B+A VLA 7 mm 7 mm VLT H−Band DEC offset (arcsec) 0.4 innerinner gapgap (cavity)(cavity) 0 + + ring ring 29 AU outer gap −0.4 outer gap (c) (d) ? ? −0.8 0.8 0.4 0 −0.4 −0.8 0.8 0.4 0 −0.4 −0.8 RA offset (arcsec) •Inner cavity <25 AU Fig. 1.— VLA images of the• 7 ~5 mm dustsigma thermal ‘overdensity’ emission in several array configurations. •Annular gap ~40-70 AU Panels (a) and (b) show, respectively, inside the the CnB cavity and B configuration~50 AU images. Panel (c) shows the image obtained by combining the CnB, B, and A configuration visibilities with a uvrange 1 <1500 kλ (rms=18 µJy beam− ; beam=0.23⇤⇤ 0.16⇤⇤, PA=5⇥). Panel (d) shows an overlay ⇥ of the image shown in panel (c) (contours) and the VLT/NACO H-band (1.6 µm) polarized light image from Quanz et al. (2013) (color-scale). Saturated pixels in the central region of the H-band image have been masked out. In all panels, contour levels are 3, 3, 5, 7, 9, and − 11 times the rms. Synthesized beams are plotted in the lower-right corners. The apparent Quanz et al. 2013b; Osorio et al. 2014 decrease of the 7 mm emission in the north and south edges of the source is most probably aconsequenceoftheelongatedbeam.ThelargercrossmarksthepositionoftheHD169142 star and the smaller one that of the protoplanet candidate. HD169142 - sequential planet formation? 1.6 micron scattered light image 3.8 micron high contrast image •Inner cavity <25 AU •3.8 micron point source •Annular gap ~40-70 AU at ~20-23 AU •Not (yet) detected at shorter wavelengths •7mm source not detected Quanz et al. 2013b; Reggiani, Quanz et al. 2014 (see also, Biller et al. 2014) 4 Avenhaus et al. P P P 5 P ⊥ ⇥ ⇥ · 2006 Hband 0.5" The Astrophysical Journal,791:136(7pp),2014August20 Brittain et al. Table 3 Properties of Excess CO v 1–0 Emission = Date Scaled Equivalent Excess Equivalent Doppler Shift FWHM Position Angle Orbital Phase Red Blue band Widtha Width ofExcess ofExcess ofExcess ofExcessb Offset Offset s 2006 2 1 2 1 1 1 (10− cm− ) (10− cm− )(kms− )(kms− )(mas)(mas) K 2003 Jan 7 4.50 0.14 40 0 12.7 3.3 14.0 3.3 ± ··· ··· ··· − ◦ ◦ ± ± 2006 Jan 14 5.69 0.59 1.19 0.61 +6 16 5 47 10 1.6 4.3 17.8 4.3 ± ± ± − ◦ ◦ ± ◦ ± ± 2010 Dec 23 6.39 0.57 1.89 0.58 1 1 12 60 97 7 5.7 4.8 25.9 4.8 ± ± − ± ◦ ◦ ± ◦ ± ± 2013 Mar 18 5.89 0.20 1.12 0.15 6 16 105133 10 10.9 0.9 35.8 0.9 ± ± − ± ◦ ◦ ± ◦ ± ± 0.5" Notes.
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