Kazuhiro D. Kanagawa

ALMA OBSERVATIONS OF A GAP AND A RING IN THE PROTOPLANETARY DISK AROUND TW HYA

We report the first detection of a gap and a ring in 336 GHz dust continuum emission from the protoplanetary disk around TW Hya, using the Atacama Large Millimeter/Submillimeter Array (ALMA). The gap and ring are located at around 25 and 41 au from the central star, respectively, and are associated with the CO snow line at ~30 au. The gap has a radial width of less than 15 au and a mass deficit of more than 23%, taking into account that the observations are limited to an angular resolution of ~15 au. In addition, the 13CO and C18O J = 3 - 2 lines show a decrement in CO line emission throughout the disk, down to ~10 au, indicating a freeze-out of gas-phase CO onto grain surfaces and possible subsequent surface reactions to form larger molecules. The observed gap could be caused by gravitational interaction between the disk gas and a planet with a mass less than super-Neptune (2M_{Neptune}), or could be the result of the destruction of large dust aggregates due to the sintering of CO ice.

MASS ESTIMATES OF A GIANT PLANET IN A PROTOPLANETARY DISK FROM THE GAP STRUCTURES

A giant planet embedded in a protoplanetary disk forms a gap. An analytic relationship among the gap depth, planet mass

Detailed structure of the outer disk around HD 169142 with polarized light in H-band

M_{p}

Meridional circulation of gas into gaps opened by giant planets in three-dimensional low-viscosity disks

, disk aspect ratio

Formation of a disc gap induced by a planet: effect of the deviation from Keplerian disc rotation

h_p

A Gap with a Deficit of Large Grains in the protoplanetary disk around TW Hya

, and viscosity

Mass constraint for a planet in a protoplanetary disk from the gap width

\alpha

The Structure of Gas-accreting Protoplanets and the Condition of the Critical Core Mass

has been found recently, and the gap depth can be written in terms of a single parameter

Modelling of deep gaps created by giant planets in protoplanetary disks

K= (M_{p}/M_{\ast})^2 h_p^{-5} \alpha^{-1}

Radial Migration of Gap-opening Planets in Protoplanetary Disks. I. The Case of a Single Planet

. We discuss how observed gap features can be used to constrain the disk and/or planet parameters based on the analytic formula for the gap depth. The constraint on the disk aspect ratio is critical in determining the planet mass so the combination of the observations of the temperature and the image can provide a constraint on the planet mass. We apply the formula for the gap depth to observations of HL~Tau and HD~169142. In the case of HL~Tau, we propose that a planet with