A Highly Settled Disk around Oph163131

Abstract High dust density in the midplane of protoplanetary disks is favorable for efficient grain growth and can allow fast formation planetesimals planets, before dissipate. Vertical settling trapping pressure maxima are two mechanisms allowing to concentrate geometrically thin high-density regions. In this work, we aim study these highly inclined disk SSTC2D J163131.2-242627 (Oph 163131, i ∼ 84°). We present new high-angular-resolution continuum 12 CO ALMA observations Oph 163131. The gas emission appears significantly more extended vertical radial direction compared emission, consistent with possibly drift. addition, reveal clear rings. outer ring, located at ∼100 au, well-resolved observations, us put stringent constraints on extent millimeter particles. model using radiative transfer find that scale height millimeter-sized grains 0.5 au or less 100 from central star. This value about one order magnitude smaller than micron-sized constrained by previous modeling, which implies large occurring disk. When adopting a parametric prescription, turbulent viscosity coefficient α ≲ 10 −5 au. Finally, measured 163131 planetary pebble accretion: M E planet may grow within Myr, even orbits exceeding 50