4:15 PM - 4:30 PM
[PPS07-16] Gap formation in protoplanetary disks by a super-Jupiter mass planet considering mass accretion onto the planet
Keywords:Planet formation, Gas accretion, Gas giants
A giant planet embedded in a protoplanetary disk creates a gap structure along with its orbit by disk-planet interaction and grows by mass accretion through the gap. The characteristics of the gap formed in the disk strongly depend on parameters such as the mass of the planet, the viscosity, and the scale heigh of the gas disk. These characteristics affect the mass accretion rate onto the planet and the rate of orbital migration of the planet. Therefore, this process is important in considering the formation and evolution of planetary systems. In addition, recent radio observations using ALMA have revealed that the existence of many protoplanetary disks with substructures such as gaps and rings, and these may have been induced by planets embedded in the disks.
Recently, research of planet-disk interaction using numerical simulation has been actively carried out, and the properties of the gap structures such as width and depth, and mass accretion rate onto the planet have been investigated in detail. However, most of the previous studies have focused on planets less massive than Jupiter. A few studies have focused on so-called super-Jupiter-mass planets, which have masses heavier than Jupiter, but the predictions of the mass accretion rates differ several orders of magnitude. Since a lot of exoplanets heavier than Jupiter have been discovered, understanding the process of their formation and evolution is important for the overall theory of planet formation.
Our previous calculation shows that the outer edge of the gap becomes unstable when the planetary mass is heavier than 3 Jupiter masses, and the low-density gas in the gap is stirred by the surrounding gas, which has the effect of increasing the surface density inside the gap. This result shows that when the planetary mass is large enough, the gap becomes shallower than predicted by an empirical formula obtained in previous studies. In this case, it is suggested that the mass accretion rate onto a super-Jupiter-mass planet will increase due to the increase of the surface density inside the gap, but at the same time, the relative velocity between the planet and the perturbed gas flow will increase, which may reduce the accretion. Therefore, it is important to treat the global structure of the disk and the process of mass accretion onto the planet at the same time in order to evaluate the mass accretion rate onto the super-Jupiter-mass planet correctly.
In this study, we performed a set of hydrodynamic simulation of disk-planet interaction taking into account the effect of mass accretion onto the planet by using FARGO. FARGO is a public code dedicated to solving the advection of rotating gas disk and is widely used in the study of disk-planet interaction. In order to test the validity of the modeling of mass accretion onto the planet used in the code, we first performed calculations with different accretion radii and accretion timescales. The results show that, when the accretion radius is taken appropriately, the results are consistent with the accretion rates obtained from previous high-resolution local simulations regardless of the accretion timescale. We also calculated the accretion rate onto the planet with different planetary masses and investigated the accretion rate when the unstable eccentric gap is induced by the super-Jupiter-mass planet. We compare these results with previous numerical calculations and discuss their implications for the formation and evolution of gas giants, especially super-Jupiter-mass planets.
Recently, research of planet-disk interaction using numerical simulation has been actively carried out, and the properties of the gap structures such as width and depth, and mass accretion rate onto the planet have been investigated in detail. However, most of the previous studies have focused on planets less massive than Jupiter. A few studies have focused on so-called super-Jupiter-mass planets, which have masses heavier than Jupiter, but the predictions of the mass accretion rates differ several orders of magnitude. Since a lot of exoplanets heavier than Jupiter have been discovered, understanding the process of their formation and evolution is important for the overall theory of planet formation.
Our previous calculation shows that the outer edge of the gap becomes unstable when the planetary mass is heavier than 3 Jupiter masses, and the low-density gas in the gap is stirred by the surrounding gas, which has the effect of increasing the surface density inside the gap. This result shows that when the planetary mass is large enough, the gap becomes shallower than predicted by an empirical formula obtained in previous studies. In this case, it is suggested that the mass accretion rate onto a super-Jupiter-mass planet will increase due to the increase of the surface density inside the gap, but at the same time, the relative velocity between the planet and the perturbed gas flow will increase, which may reduce the accretion. Therefore, it is important to treat the global structure of the disk and the process of mass accretion onto the planet at the same time in order to evaluate the mass accretion rate onto the super-Jupiter-mass planet correctly.
In this study, we performed a set of hydrodynamic simulation of disk-planet interaction taking into account the effect of mass accretion onto the planet by using FARGO. FARGO is a public code dedicated to solving the advection of rotating gas disk and is widely used in the study of disk-planet interaction. In order to test the validity of the modeling of mass accretion onto the planet used in the code, we first performed calculations with different accretion radii and accretion timescales. The results show that, when the accretion radius is taken appropriately, the results are consistent with the accretion rates obtained from previous high-resolution local simulations regardless of the accretion timescale. We also calculated the accretion rate onto the planet with different planetary masses and investigated the accretion rate when the unstable eccentric gap is induced by the super-Jupiter-mass planet. We compare these results with previous numerical calculations and discuss their implications for the formation and evolution of gas giants, especially super-Jupiter-mass planets.