A three-dimensional axisymmetric photochemical flow model of the cometary 'inner' shock layer

Abstract

view Abstract Citations (11) References (28) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Three-dimensional Axisymmetric Photochemical Flow Model of the Cometary ``Inner'' Shock Layer Damas, M. C. ; Mendis, D. A. Abstract Assuming the Newtonian thin layer approximation to describe the structure of the shock layer between the cometary 'ionopause' and the inner shock, a 3D axisymmetric photochemical flow model of this layer is constructed. While sources of ions in this layer are the flow across the inner shock and photoionization of neutrals within it, the sinks are the flow into the flanks and dissociative recombination, the latter being the dominant one. For Halley's comet at the time of the Giotto encounter, the calculated thickness of the layer is very small, typically about 100 km for expected values of the dissociative-recombination coefficient. This is not inconsistent with the observations. The lateral flow speed near the point of encounter (inbound) is about 0.9 km/s, while the sonic line is at an angle of about 50 deg to the sun-comet line. Testing the validity of this model will have to await a cometary rendezvous mission such as the proposed CRAF/Cassini mission. Publication: The Astrophysical Journal Pub Date: September 1992 DOI: 10.1086/171752 Bibcode: 1992ApJ...396..704D Keywords: Cometary Atmospheres; Halley'S Comet; Magnetohydrodynamic Flow; Shock Layers; Three Dimensional Flow; Flow Distribution; Giotto Mission; Ionopause; Magnetoacoustic Waves; Newtonian Fluids; Astrophysics; COMETS: GENERAL; SHOCK WAVES full text sources ADS |