Optical/IR images of transition disks (TDs) have revealed deep intensity decrements in the rings of HAeBes HD 142527 and HD 100453, that can be interpreted as shadowing from sharply tilted inner disks, such that the outer disks are directly exposed to stellar light. Here we report similar dips in SPHERE+IRDIS differential polarized imaging (DPI) of TTauri DoAr 44. With a fairly axially symmetric ring in the sub mm radio continuum, DoAr 44 is likely also a warped system. We constrain the warp geometry by comparing radiative transfer predictions with the DPI data in H band (Q φ (H)) and with a re-processing of archival 336 GHz ALMA observations. The observed DPI shadows have coincident radio counterparts, but the intensity drops are much deeper in Q φ (H) (∼88%), compared to the shallow drops at 336 GHz (∼24%). Radiative transfer predictions with an inner disk tilt of ∼ 30 ± 5 deg approximately account for the observations. ALMA long-baseline observations should allow the observation of the warped gas kinematics inside the cavity of DoAr 44.

We present ALMA 1.3 mm continuum observations at 0.2 (25 au) resolution of Elias 2-24, one of the largest and brightest protoplanetary disks in the Ophiuchus Molecular Cloud, and report the presence of three partially resolved concentric

Planet-disc interactions build up local pressure maxima that may halt the radial drift of protoplanetary dust, and pile it up in rings and crescents. ALMA observations of the HD 135344B disc revealed two rings in the thermal continuum stemming from ∼mm-sized dust. At higher frequencies the inner ring is brighter relative to the outer ring, which is also shaped as a crescent rather than a full ring. In near-IR scattered light images, the disc is modulated by a 2-armed grand-design spiral originating inside the ALMA inner ring. Such structures may be induced by a massive companion evacuating the central cavity, and by a giant planet in the gap separating both rings, that channels the accretion of small dust and gas through its filamentary wakes while stopping the larger dust from crossing the gap. Here we present ALMA observations in the J = (2 − 1) CO isotopologue lines and in the adjacent continuum, with up to 12 km baselines. Angular resolutions of ∼0${_{.}^{\prime\prime}}$03 reveal the tentative detection of a filament connecting both rings, and which coincides with a local discontinuity in the pitch angle of the IR spiral, proposed previously as the location of the protoplanet driving this spiral. Line diagnostics suggest that turbulence, or superposed velocity components, is particularly strong in the spirals. The 12CO(2-1) 3-D rotation curve points at stellocentric accretion at radii within the inner dust ring, with a radial velocity of up to $\sim 5\%\pm 0.5\%$ Keplerian, which corresponds to an excessively large accretion rate of ∼2 × 10−6 M⊙ yr−1 if all of the CO layer follows the 12CO(2-1) kinematics. This suggests that only the surface layers of the disc are undergoing accretion, and that the line broadening is due to superposed laminar flows.

The large crescents imaged by ALMA in transition disks suggest that azimuthal dust trapping concentrates the larger grains, but centimetre-wavelengths continuum observations are required to map the distribution of the largest observable grains. A previous detection at ∼1 cm of an unresolved clump along the outer ring of MWC 758 (Clump 1), and buried inside more extended sub-mm continuum, motivates followup VLA observations. Deep multiconfiguration integrations reveal the morphology of Clump 1 and additional cm-wave components which we characterize via comparison with a deconvolution of recent 342 GHz data (∼1 mm). Clump 1, which concentrates ∼ 1/3 of the whole disk flux density at ∼1 cm, is resolved as a narrow arc with a deprojected aspect ratio χ > 5.6, and with half the azimuthal width than at 342 GHz. The spectral trends in the morphology of Clump 1 are quantitatively consistent with the Lyra-Lin prescriptions for dust trapping in an anticyclonic vortex, provided with porous grains ( f ∼ 0.2 ± 0.2) in a very elongated ( χ ∼ 14 ± 3) and cold (T ∼ 23 ± 2 K) vortex. The same prescriptions constrain the turbulence parameter α and the gas surface density Σ g through log 10 α × Σ g /g cm −2 ∼ −2.3 ± 0.4, thus requiring values for Σ g larger than a factor of a few compared to that reported in the literature from the CO isotopologues, if α 10 −3 . Such physical conditions imply an appreciably optically thick continuum even at cm-wavelengths (τ 33 GHz ∼ 0.2). A secondary and shallower peak at 342 GHz is about twice fainter relative to Clump 1 at 33 GHz. Clump 2 appears to be less efficient at trapping large grains.