Probing inner and outer disk misalignments in transition disks

Abstract

Context. Transition disks are protoplanetary disks with dust-depleted cavities, possibly indicating substantial clearing of their dust content by a massive companion. For several known transition disks, dark regions interpreted as shadows have been observed in scattered light imaging and are hypothesized to originate from misalignments between distinct regions of the disk. Aims. We aim to investigate the presence of misalignments in transition disks. We study the inner disk (<1 au) geometries of a sample of 20 well-known transition disks with Very Large Telescope Interferometer (VLTI) GRAVITY observations and use complementary 12CO and 13CO molecular line archival data from the Atacama Large Millimeter/submillimeter Array (ALMA) to derive the orientation of the outer disk regions (>10 au). Methods. We fit simple parametric models to the visibilities and closure phases of the GRAVITY data to derive the inclination and position angle of the inner disks. The outer disk geometries were derived from Keplerian fits to the ALMA velocity maps and compared to the inner disk constraints. We also predicted the locations of expected shadows for significantly misaligned systems. Results. Our analysis reveals six disks to exhibit significant misalignments between their inner and outer disk structures. The predicted shadow positions agree well with the scattered light images of HD 100453 and HD 142527, and we find supporting evidence for a shadow in the south of the disk around CQ Tau. In the other three targets for which we infer significantly misaligned disks, V1247 Ori, V1366 Ori, and RY Lup, we do not see any evident sign of shadows in the scattered light images. The scattered light shadows observed in DoAr 44, HD 135344 B, and HD 139614 are consistent with our observations, yet the underlying morphology is likely too complex to be described properly by our models and the accuracy achieved by our observations. Conclusions. The combination of near infrared and submillimeter interferometric observations allows us to assess the geometries of the innermost disk regions and those of the outer disk. Whereas we can derive precise constraints on the potential shadow positions for well-resolved inner disks around Herbig Ae/Be stars, the large statistical uncertainties for the marginally resolved inner disks around the T Tauri stars of our sample make it difficult to extract conclusive constraints for the presence of shadows in these systems.

Improved Orbital Constraints and Hα Photometric Monitoring of the Directly Imaged Protoplanet Analog HD 142527 B

“…Narrow "shadow" features have been observed along the outer disk cavity wall, suggesting that this inner disk may be inclined with respect to the outer disk (Marino et al 2015). Bohn et al (2022) provided the first resolved measurements of the inner disk using VLTI/GRAVITY observations, which they used to investigate the mutual alignments of the inner and outer disk components. They found that the K-band complex visibilities of their data were best fit by an inner disk model with an inclination of i d,inn = 23°.76 ± 3°.…”

“…We determine the posterior distribution of mutual inclinations between the binary orbit and both the inner and outer disk components (shown in Figure 15) by drawing random samples from the posterior distribution of i å and Ω å produced by orbitize!, and assuming a Gaussian distribution for the disk orientation centered on the values most recently inferred from ALMA gas kinematic data for the outer disk (i disk,outer = 38°.21 ± 1°.38, Ω disk,outer = 162°.72 ± 1°. 38; Perez et al 2015;Boehler et al 2017;Bohn et al 2022), and VLTI/GRAVITY observations for the inner disk (i disk,inner = 23°.76 ± 3°.18, Ω disk,inner = 15°.44 ± 7°.44; Bohn et al 2022).…”

“…Figure14illustrates the posterior distribution of orbital elements for the HD 142527 AB binary. Figure15plots the mutual inclination parameters i å , Ω å from Figure14, computed as described in Section 5, along with i d , Ω d drawn from Gaussian distributions specified by the disk parameters fit byBohn et al (2022), and the resultant distribution of mutual inclinations θ. Figure16illustrates the posterior distribution for the orbit of the θ 1 Ori B2-B3 derived from Keck NIRC2 observations, as described in Appendix A.…”

Kinematic Structures in Planet-Forming Disks

“…High-resolution sub-mm continuum observations with ALMA have beautifully exposed a large-scale warp in GW Ori (Kraus et al 2020;Bi et al 2020), whose triple ring system is seen as a projected ellipses with different inclinations. Gravity Collaboration et al (2021) detected clear misalignments between both disks for 4 objects out of 9 transition disks, while Bohn et al (2022) detected additional misalignments in 6 targets out of sample of 20 transition disks. For 3 of those targets the orientation of the inner disk is consistent with the shadows detected in scattered light in the outer disks.…”

External or internal companion exciting the spiral arms in CQ Tau?

“…The observations used in this work are summarised in Table 2. All are new to this work, with the exception of program 098.C-0760 (2017-10-06) which is presented in Appendix E of Bohn et al (2022). Together, they represent all currently available ESO high-contrast imaging data for CQ Tau.…”