eDisk Modeling of a Protostellar Disk: Flared Dust Distribution and Viscous Accretion Heating of the Disk around R CrA IRS 7B-a

Shigehisa Takakuwa  (Kagoshima University)

We performed radiative transfer calculations and observing simulations to reproduce the 1.3-mm dust-continuum and C18O (2–1) images in the Class I protostar R CrA IRS7B-a, observed with eDisk. We found that the dust disk model passively heated by the central protostar cannot reproduce the observed peak brightness temperature of the 1.3-mm continuum emission (∼195 K), and that viscous accretion heating in the disk is required to reproduce the observed high brightness temperature. The observed intensity profile of the 1.3-mm dust-continuum emission along the disk minor axis is skewed toward the disk far side. Our modeling reveals that such an asymmetric intensity distribution requires flaring of the dust along the disk’s vertical direction with the scale-height following h/r ∼ r0.3 as function of radius. From our modeling of the C18O (2–1) emission, the outermost radius of the gas disk is estimated to be ∼80 au, larger than that of the dust disk (∼62 au), to reproduce the observed distribution of the C18O (2–1) emission in IRS 7B-a. We will show these results and implications as compared to more evolved Class II sources.