The vertical structure of planet-induced gaps in protoplanetary discs

• Published in: Monthly notices of the Royal Astronomical Society Vol. 387; no. 1; pp. 387 - 396
• Main Authors: Edgar, Richard G., Quillen, Alice C.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2008; Blackwell Science; Oxford University Press
• Subjects: Astronomy; Astrophysics; Earth, ocean, space; Exact sciences and technology; Extrasolar planets; planetary systems: protoplanetary discs; Protoplanetary disks; planetary systems: protoplanetary discs; Submillimeter wave radiation; Spiral arm; Infrared observation; Giant planet; Circumstellar disks; Radio observation; Planetary system; Mach number
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2008.13242.x

Giant planets embedded in circumstellar discs are expected to open gaps in these discs. We examine the vertical structure of the gap edges. We find that the planet excites spiral arms with significant (Mach number of a half) vertical motion of the gas, and discuss the implications of these motions. In particular, the spiral arms will make the edge appear ‘puffed up’ relative to the bulk of the disc. Infrared observations (sensitive to dust) would be dominated by the light from the thick inner edge of the disc. Submillimetre observations (sensitive to gas velocities) would appear to be hot in ‘turbulent’ motions (actually the ordered motion caused by the passage of the spiral arms), but cold in chemistry. Resolved submillimetre maps of circumstellar discs might even be able to detect the spiral arms directly.