Photoevaporation as a Truncation Mechanism for Circumplanetary Disks

Abstract

We investigate the conditions under which the regular satellites of Jupiter and Saturn formed. The final stage of giant planet accretion is thought to occur slowly over a relatively long, 10 Myr, timescale. Gas accretion during this stage, through a completely or partially opened gap in the solar nebula, occurs slowly allowing for the condensation of ices, and incomplete differentiation, seen in the regular satellites of the giant planets. Furthermore, the dichotomy seen in the Jovian and Saturnian systems may be explained as this infall wanes or is completely shutoff as a result of gap opening or global depletion of gas in the solar nebula. We present one-dimensional simulations of circumplanetary disks that couple the viscous transport of material with the loss of mass at the disk outer edge by ultraviolet photoevaporation as well as the infall of material from the solar nebula. We find that the circumplanetary disks of these protoplanets are truncated, as a result of photoevaporation, at a range of values with the mean corresponding to $\approx$ 0.16 Hill radii. These truncation radii are broadly consistent with the current locations of the regular satellite systems of Jupiter and Saturn. We also find that photoevaporation can successfully act as a clearing mechanism for circumplanetary nebulae on the potentially short timescales, 100-10,000 yr, over which mass accretion from the solar nebula wanes as a result of gap opening. Such a rapid clearing of the circum-Jovian disk may be required to explain the survival of the Galilean satellites.

6 pages, 6 figures, accepted for publication in the Astronomical Journal

References in corpus (7)

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• Halting Type I planet migration in non-isothermal disks
• Cavity opening by a giant planet in a protoplanetary disc and effects on planetary migration
• The Photoevaporation of Discs Around Young Stars in Massive Clusters
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Cited by in corpus (9)

• Early evolution of the birth cluster of the solar system
• Magnetic Coupling in the Disks Around Young Gas Giant Planets
• Cradle(s) of the Sun
• Significant interstellar object production by close stellar flybys
• Circumplanetary disk ices. I. Ice formation vs. viscous evolution and grain drift
• Photoevaporation of the Jovian circumplanetary disk I. Explaining the orbit of Callisto and the lack of outer regular satellites
• Observing Circumplanetary Disks with METIS
• Hydrogen-loosing planets in transition discs around young protostars
• New Mid-Infrared Imaging Constraints on Companions and Protoplanetary Disks around six Young Stars