Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-26T16:50:36.618Z Has data issue: false hasContentIssue false

Hydrodynamic Models of the Collisional Coma

Published online by Cambridge University Press:  12 April 2016

J.F. Crifo*
Affiliation:
CNRS/IASBP 10 F91371 Verrières CedexFrance

Abstract.

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The hydrodynamic approach to the modeling of the collisional regions of the cometary atmospheres is reviewed. A concise account of the existing Monte Carlo simulations is also incorporated. Emphasis is placed on works stimulated by the Halley flyby missions. The basic physical processes are described, based on the analogy with the physics of underexpanded jets. The general structure of the governing equations is presented and their legacy discussed. A detailed intercomparison is made of the application of these methods to the modeling of the comas. The reliability of the conclusions brought forward by existing models is discussed.

Type
Section V: The Cometary Coma
Copyright
Copyright © Kluwer 1991

References

1. Allen, M., Delitsky, M., Huntress, W., Yung, Y., Ip, W.-H., Schwenn, R., Rosenbauer, H., Shelley, E., Balsiger, H., and Geiss, J. (1987). ‘Evidence for methane and ammonia in the coma of comet Halley,’ Astron. Astrophys. 187, 502512.Google Scholar
2. Anderson, J.B., Foch, J.D., Shaw, M.J., Stern, R.C., and Wu, B.J. (1986). ‘Monte Carlo simulation of free-jet flow from a slit,’ in Cercignani, C. and Boffi, V. (eds.), Rarefied Gas Dynamics XV, Teubner Press, Stuttgart, Vol. 1, pp. 442451.Google Scholar
3. Ashkenas, H., and Sherman, T.S. (1966). ‘The structure and utilization of supersonic free-jets in low-density wind tunnels,’ in de Leeuw, J.H. (ed.), Rarefied Gas Dynamics IV, Academic Press, New York, Vol. 2, pp. 84105.Google Scholar
4. Banaskiewicz, M., Marconi, M., Kömle, N.I., and Ip, W.H. (1989). ‘Dynamics of large grains around Halley’s comet,’ poster presented at “Comets in the Post-Halley Era,” Bamberg, F.R.G. Google Scholar
5. Bisikalo, D.V., Marov, M.Ya., Shematovich, V.I., and Strel’nitsky, V.S.(1989). ‘The flow of the subliming gas in the near-nuclear (Knudsen) layer of the cometary coma,’ Adv. Space Res. 9 (3), 5358.Google Scholar
6. Bockelee-Morvan, D. (1987). ‘A model for the excitation of water in comets,’ Astron. Astrophys. 181, 169181.Google Scholar
7. Bockelee-Morvan, D., and Crovisier, J. (1987). ‘The role of water in the thermal balance of the coma,’ ESA SP-278, pp. 235240.Google Scholar
8. Burgers, J.M. (1969). Flow Equations for Composite Gases, Academic Press, New York.Google Scholar
9. Campbell, D.B., Harmon, J.K., and Shapiro, I.I. (1989). ‘Radar observations of comet Halley,’ Astrophys. J. 338, 10941105.Google Scholar
10. Cattolica, R., Robben, F., Talbot, L., and Willis, D.R. (1974). ‘Translational non-equilibrium in free-jet expansion,’ Phys. Fluids, 17 (10), 17931807.Google Scholar
11. Combi, M.R. (1987). ‘Sources of cometary radicals and their jets: Gases or grains,’ Icarus 71, 178191.Google Scholar
12. Combi, M.R. (1989). ‘The outflow speed of the coma of Halley’s comet,’ Icarus 81, 4150.Google Scholar
13. Combi, M.R., and Smyth, W.H. (1988). ‘Monte Carlo particle trajectory models for neutral coma gases. I. Models and equations,’ Astrophys. J. 327, 10261043; and Combi, M.R., and Smyth, W.H. (1988). ‘Monte Carlo particle trajectory models for neutral coma gases. II. The spatial morphology of the Lyman alpha coma,’ Astrophys. J. 327, 10441059.Google Scholar
14. Cravens, T.E. (1989). ‘A magnetohydrodynamic model of the inner coma of Comet Halley,’ J. Geophys. Res. 94 (All), 15,02515,040.Google Scholar
15. Crifo, J.F. (1986a). ‘Hydrodynamic expansion of cometary gas loaded with refractory and volatile grains,’ in Lagerkvist, C.I. et al. (eds.), Asteroids, Comets, Meteors H, Reprocentralen HSC, Uppsala, pp. 389392.Google Scholar
16. Crifo, J.F. (1986b). ‘Comets as dirty snowballs sublimating in empty space,’ in Cercignani, C. and Boffi, V. (eds.), Rarefied Gas Dynamics XV, Teubner Press, Stuttgart, pp. 229250.Google Scholar
17. Crifo, J.F. (1987a). ‘Improved gas kinetic treatment of cometary water sublimation and recondensation, application to comet P/Halley,’ Astron. Astrophys. 187, 438450.Google Scholar
18. Crifo, J.F. (1987b). ‘Optical and hydrodynamic implications of Comet Halley dust size distribution,’ ESA SP-278, pp. 399408.Google Scholar
19. Crifo, J.F. (1987c). ‘Are cometary dust mass loss rates deduced from optical emissions reliable?’, in Ceplecha, Z. and Pecina, P. (eds.), Interplanetary Matter, Proceedings of the Xth ERAM IAU Meeting, Prague, Czechoslovakia, Czechoslovak Academy of Sciences report G7, pp. 5966.Google Scholar
20. Crifo, J.F. (1989). ‘Collisional coma models: An unorthodox overview,’ Adv. Space Res. 9 (3), 197211.CrossRefGoogle Scholar
21. Crifo, J.F. (1990a). ‘Water clusters in the coma of Comet Halley and their effect on the gas density, temperature and velocity,’ Icarus, in press.Google Scholar
22. Crifo, J.F. (1990b). ‘A realistic simple size approximation to Comet Halley dust size distribution, suitable for hydrodynamic applications,’ preprint.Google Scholar
23. Crifo, J.F., Crovisier, J., and Bockelee-Morvan, D. (1989). ‘Proposed water velocity and temperature radial profiles appropriate to Comet Halley flyby conditions,’ poster presented at “Comets in the Post-Halley Era,” Bamberg, F.R.G. Google Scholar
24. Crovisier, J. (1984). ‘The water molecule in comets: Fluorescence mechanisms and thermodynamics of the inner coma,’ Astron. Astrophys. 130, 361372.Google Scholar
25. Crovisier, J. (1989). ‘The photodissociation of water in cometary atmospheres,’ Astron. Astrophys. 213, 459464.Google Scholar
26. Festou, M. (1981). ‘The density distribution of neutral compounds in cometary atmospheres,’ Astron. Astrophys. 95, 6979.Google Scholar
27. Fulle, M. (1989). ‘Evaluation of cometary dust parameters from numerical simulations: Comparison with analytical approach and role of anisotropic emissions,’ Astron. Astrophys. 217, 283297.Google Scholar
28. Fulle, M. (1990). ‘A neck-line structure in the dust tail of comet 19101,’ preprint.Google Scholar
29. Gombosi, T.I. (1986). ‘A heuristic model of the Comet Halley dust size distributions,’ ESA SP-250, pp. 167171.Google Scholar
30. Gombosi, T.I., Cravens, T.E., and Nagy, A.F. (1985). ‘Time-dependent dusty gas dynamical flow near cometary nuclei,’ Astrophys. J. 293, 328341.Google Scholar
31. Gombosi, T.I., Nagy, A.F., and Cravens, J.E. (1985). ‘Dust and neutral gas modeling of the inner upper atmosphere of comets,’ Rev. Geophys. 24, 667700.Google Scholar
32. Gustafson, B.A. (1989). ‘Comet ejections and dynamics of nonspherical dust particles and meteroids,’ Astrophys. J. 337, 945949.Google Scholar
33. Hodges, R.R. (1990a). ‘Monte Carlo simulation of nonadiabatic expansion in cometary atmospheres: Halley,’ Icarus 83, 410433.Google Scholar
34. Hodges, R.R. (1990b). ‘Aspheric flow of water vapor in cometary atmospheres,’ preprint.Google Scholar
35. Huebner, W.F. (1985). ‘The photochemistry of comets,’ in Levine, J.J. (ed.), The Photochemistry of Atmospheres, Academic Press, Orlando, pp. 438508.Google Scholar
36. Huebner, W.F., and Keady, J.J. (1983). ‘Energy balance and photochemical processes in the inner coma,’ in Gombosi, T.I. (ed.), Cometary Exploration, Academy of Hungary Press, Budapest, pp. 165183.Google Scholar
37. Huebner, W.F., and Keady, J.J. (1984). ‘First-flight escape from spheres with r-2 density distribution,’ Astron. Astrophys. 135, 177180.Google Scholar
38. Ip, W.H. (1983). ‘Photochemical heating of the cometary plasma,’ Astrophys. J. 264, 726732.Google Scholar
39. Ip, W.H. (1986). ‘Photochemical heating of comets: The effect of icy water droplet recondensation,’ Astrophys. J. 300, 456460.Google Scholar
40. Ip, W.H. (1989). ‘Photochemical heating of cometary gases: in. The radial variation of the expansion velocity of CN shells in Comet Halley,’ Astrophys. J. 346, 475480.CrossRefGoogle Scholar
41. Keller, H.U., Delamere, W.A., Huebner, W.F., Reitsema, H.J., Schmidt, H.U., Whipple, F.L., Wilhelm, K., Curdt, W., Kramm, R., Thomas, N., Arpigny, C., Barbieri, C., Bonnet, R.M., Cazes, S., Coradini, M., Cosmovici, C.B., Hughes, D.W., Jamar, C., Malaise, D., Schmidt, K., Schmidt, W.K.H., and Seige, P. (1987). ‘Comet P/Halley’s nucleus and its activity,’ Astron. Astrophys. 187, 807823.Google Scholar
42. Keller, U.H., Marconi, M.L., and Thomas, N. (1990). ‘Hydrodynamic implications of particle fragmentation near cometary nuclei,’ Astron. Astrophys. 227, L1L4.Google Scholar
43. Kitamura, Y., Ashihara, U., and Yamamoto, T. (1985). ‘A model for the hydrogen coma of a comet,’ Icarus 61, 278295.Google Scholar
44. Kitamura, Y., and Yamamoto, T. (1986). ‘Hydrodynamic study of condensation and sublimation of ice particles in cometary atmospheres,’ Icarus 68 (2), 266275.Google Scholar
45. Kitamura, Y. (1986). ‘Axisymmetric dusty gas jet in the inner coma of a comet,’ Icarus 66, 241257.Google Scholar
46. Kitamura, Y. (1987). ‘Axisymmetric dusty gas jet in the inner coma of a comet. I. The case of isolated jets,’ Icarus 72, 555567.Google Scholar
47. Kitamura, Y. (1988). ‘Numerical study of 3-dimensional cometary jets: Formation of shock waves in cometary atmospheres,’ in Proceedings of the XXth ISAS Lunar and Planetary Symposium, Tokyo, pp. 3334. Also, preprint (1989).Google Scholar
48. Kömle, N.I. (1990). ‘Jet and shell structures in the cometary coma,’ in Mason, J. (ed.), Comet Halley 1986: Worldwide Investigations, Results and Interpretations, J. Wiley, New York, in press.Google Scholar
49. Kömle, N.I., and Ip, W.H. (1987a). ‘A model for the anisotropic structure of the neutral gas coma of a comet,’ ESA SP-278, 247254.Google Scholar
50. Kömle, N.I., and Ip, W.H. (1987). ‘Anisotropic non-stationary gas flow dynamics in the coma of Comet P/Halley,’ Astron. Astrophys. 187, 405410.Google Scholar
51. Körösmezey, A., Cravens, T.E., Gombosi, T.I., Nagy, A.F., Mendis, D.A., Szegő, K., Gribov, B.E., Sagdeev, R.Z., Shapiro, V.D., and Shevchenko, V.I. (1987). ‘A new model of cometary ionospheres,’ J. Geophys. Res. 92 (A7), 73317340.Google Scholar
52. Körösmezey, A., and Gombosi, T.I. (1990). ‘A time-dependent dusty-gas dynamic model of axisymmetric cometary jets,’ Icarus, 84, 118153.CrossRefGoogle Scholar
53. Lämmerzahl, P., Krankowsky, D., Hodges, R.R., Stubbemann, U., Woweries, J., Herrwerth, I., Berthelier, J.J., Illiano, J.M., Eberhardt, P., Dolder, U., Schulte, W., and Hoffman, J.H. (1987). ‘Expansion velocity and temperature of gas and ions measured in the coma of Comet P/Halley,’ Astron. Astrophys. 187, 169173.Google Scholar
54. Mager, R., Adomeit, G., and Wortberg, G. (1989). ‘Theoretical and experimental investigation of the strong evaporation of solids,’ in Muntz, E.P. et al. (eds.), Rarefied Gas Dynamics: Space Related Studies, Progress in Astronautics and Aeronautics, Vol. 118, AIAA Press, Washington, D.C., pp. 460469.Google Scholar
55. Mc Donnell, J.A.M., Alexander, W.M., Burton, W.M., Bussoletti, E., Evans, G.C., Evans, S.T., Firth, J.G., Grard, R.J.L., Green, S.F., Grun, E., Hanner, M.S., Hughes, D.W., Igenbergs, E., Kissel, J., Kuczera, H., Lindblad, B.A., Langevin, Y., Mandeville, J.-C., Nappo, S., Pankiewicz, G.S.A., Perry, C.H., Schwehm, G.H., Sekanina, Z., Stevenson, T.J., Turner, R.F., Weishaupt, U., Wallis, M.K., and Zarnecki, J.C. (1987). ‘The dust distribution within the inner coma of comet P/Halley 1982i: Encounter by Giotto’s impact detectors,’ Astron. Astrophys. 187, 719741.Google Scholar
56. Mcintosh, B.A., and Jones, J. (1988). ‘The Halley comet meteor stream: Numerical modelling of its dynamical evolution,’ Mon. Not. R. Astr. Soc. 235, 673693.Google Scholar
57. Marconi, M.L. (1986). ‘The effect of dust IR and H2O IR on the thermodynamics of Comet Halley’s atmosphere,’ unpublished UCSD report.Google Scholar
58. Marconi, M.L., and Mendis, D.A. (1983). ‘The atmosphere of a dirty clathrate cometary nucleus: A two phase multifluid model,’ Astrophys. J. 273, 381396.Google Scholar
59. Marconi, M.L., and Mendis, D.A. (1984). ‘The effects of the diffuse radiation fields due to multiple scattering and thermal reradiation by dust on the dynamics and thermodynamics of a dusty cometary atmosphere,’ Astrophys. J. 287, 445454.Google Scholar
60. Marconi, M.L., and Mendis, D.A. (1986). ‘Infrared heating of Comet Halley’s atmosphere,’ The Moon and Planets, 36, 249256.Google Scholar
61. Mazets, E.P., Sagdeev, R.Z., Aptekar, R.L., Golenetskii, S.V., Guryan, Yu.A., Dyachkov, A.V., Ilyinskii, V.N., Panov, V.N., Petrov, G.G., Savvin, A.V., Sokolov, I.A., Frederiks, D.D., Khavenson, N.G., Shapiro, V.D., and Shevchenko, V.I. (1987). ‘Dust in comet P/Halley from Vega observations,’ Astron. Astrophys. 187, 699706.Google Scholar
62. Mendis, D.A., Houpis, L.F., and Marconi, M.L. (1985). ‘The physics of comets,’ Fundam. Cosm. Phys. 10, 1379.Google Scholar
63. Muntz, E.P. (1989). ‘Rarefied gas dynamics,’ Ann. Rev. Fluid Mech. 21, 387417.CrossRefGoogle Scholar
64. Olsson-Steel, D. (1987). ‘The dispersal of meteroid streams by radiative effects,’ in Ceplecha, Z. and Pecina, P. (eds.), Interplanetary Matter, Proceedings of the Xth ERAM IAU Meeting, Prague, Czechoslovakia, Czechoslovak Academy of Sciences report G7, pp. 157161.Google Scholar
65. Peyret, R., and Viviand, H. (1976). ‘Computations of viscous compressible flows based on the Navier Stokes Equation,’ Nato AGARD publication AG 212.Google Scholar
66. Probstein, R.F. (1969). ‘The dusty gas dynamics of comet heads,’ in Lavrentiev, M.A. (ed.), Problems of Hydrodynamics and Continuum Mechanics, SIAM, Philadelphia, pp. 568583.Google Scholar
67. Rickman, H. (1989). ‘The nucleus of Comet Halley: Surface, structure, mean density, gas and dust production,’ Adv. Space Res. 9 (3), 5972.Google Scholar
68. Salo, H. (1988). ‘Monte Carlo modelling of the net effects of coma scattering and thermal reradation on the energy input to cometary nucleus,’ Icarus 76 (2), 253269.Google Scholar
69. Schmidt, H.U., Wegmann, R., Huebner, W.F., and Boice, D.C. (1988). ‘Cometary gas and plasma flow with detailed chemistry,’ Comput. Phys. Comm. 49 (1), 1759.Google Scholar
70. Schulz, R., and Schlosser, W. (1989). ‘CN-shell structures and dynamics of the nucleus of Comet P/Halley,’ Astron. Astrophys. 214, 375385.Google Scholar
71. Shimizu, M. (1976). ‘The structure of cometary I. atmospheres Temperature distribution,’ Astrophys. Space Sci. 40, 149155.Google Scholar
72. Shul’man, L.M. (1970). ‘The physical conditions in the boundary layer of a cometary nucleus,’ Astron. Astrophys. 4, translated as NASA-N70–30776, pp. 100109.Google Scholar
73. Shul’man, L.M. (1972). ‘Dinamika Kometnikh Atmosfer Neitralnii Gas,’ Naukova Dumka, Kiev, pp. 170173 (in Russian).Google Scholar
74. Sykes, M.V. (1988). ‘Observations of extended zodiacal structures,’ Astrophys. J. 334, L55L58.Google Scholar
75. Szegő, K., Toth, I., Szatmary, Z., Smith, B.A., Kondor, A., and Merenyi, E. (1989). ‘Dust photometry in the near nucleus region of Comet Halley,’ submitted to Icarus.Google Scholar
76. Thomas, N., and Keller, U.H. (1987). ‘Fine dust structures in the emission of comet P/Halley observed by the Halley Multicolour Camera on board Giotto,’ Astron. Astrophys. 187, 843846.Google Scholar
77. Thomas, N., and Keller, U.H. (1990). ‘Interpretation of the inner coma observations of Comet P/Halley by the Halley Multicolor Camera,’ Ann. Geophys. 8, 147166.Google Scholar
78. Vergazov, M.A., and Krasnobaev, K.V. (1985). ‘Axisymmetric flow of reacting gas from a comet nucleus,’ Sov. Astron. Lett. 11 (4), 232235.Google Scholar
79. Vincenti, W.G., and Kruger, C.H. (1975). Introduction to Physical Gas Dynamics, J. Wiley, New York.Google Scholar
80. Wallis, M.K. (1982). ‘Dusty gas dynamics in real comets,’ in Wilkening, L.L. (ed.), Comets, University of Arizona Press, Tucson, pp. 357369.Google Scholar
81. Wallis, M.K., Rabilizirov, R., and Wickramasinghe, N.C. (1987). ‘Evaporating grains in P/Halley’s coma,’ Astron. Astrophys. 187, 801806.Google Scholar
82. Weaver, H.A., and Mumma, M.J. (1987). ‘Infrared investigations of water in Comet P/Halley,’ Astron. Astrophys. 187, 411418.Google Scholar
83. Wegman, R., Schmidt, H.U., Huebner, W.F., and Boice, D.C. (1987). ‘Cometary MHD and chemistry,’ Astron. Astrophys. 187, 339350.Google Scholar
84. Wu, Z.J. (1988). ‘Calculation of the shape of the contact surface at Comet Halley,’ Ann. Geophys. 88, 355360.Google Scholar
85. Ytrehus, T., and Gjernes, E. (1988). ‘Dusty Knudsen layers in cometary gas dynamics,’ Bulg. Acad. Sci. Theoretical and Applied Mechanics 3, 99; also preprint (1989).Google Scholar