Energy balance and the gas flux from the surface of comet 46P/Wirtanen |
| |
| Institution: | 1. DLR Institute of Planetary Exploration, Rudower Chaussee 5, Bldg. 16.16, D-12489 Berlin, Germany;1. Department of Clinical Nutrition and Dietetics, National Nutrition and Food Technology Research Institute, Faculty of Nutrition Science and Food Technology, Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran;2. Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, United States;3. School of Medicine, Federal University of Uberlandia (UFU), Uberlandia, Minas Gerais, Brazil;4. Department of Cellular and Molecular Nutrition, National Nutrition and Food Technology Research Institute, Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran;5. Department of Cellular and Molecular, Nutrition School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran;6. Student Research Committee, Department of Nutrition, School of Public Health, Iran University of Medical Sciences, Tehran, Iran;7. Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran;8. UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia;9. “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania;10. Department of Geriatrics and Long Term Care, Rumailah Hospital, Doha, Qatar;11. Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran;12. Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran;13. College of Health Sciences, QU-Health, Qatar University, Doha, Qatar;14. Center of Hematology and Bone Marrow Transplantation, Fundeni Clinical Institute, Bucharest, Romania;1. Department of Medical Oncology, Radboud University Medical Center, Nijmegen, the Netherlands;2. Department of Urology, Radboud University Medical Center, Nijmegen, the Netherlands;3. Department of Medical Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA;4. Department of Medical Oncology, Hospital Moinhos de Vento, Porto Alegre, Brazil;5. Department of Tumor Immunology, Radboud University Medical Center, Nijmegen, the Netherlands;6. Department of Pathology, Radboud University Medical Center, Nijmegen, the Netherlands |
| |
| Abstract: | Understanding the power balance at the surface of the nucleus is essential to study the chemical and physical evolution of a comet. Therefore, we present a detailed energy budget analysis for the surface of a model comet in the orbit of 46P/Wirtanen, target comet of the European space craft mission Rosetta, for a variety of parameters and assumptions. We will show that for a fast spinning Jupiter-family comet such as 46P/Wirtanen with a rotation period of about 6 h, a fast rotator approximation underestimates the effective energy input. This yields lower gas fluxes from the surface. For an 100% active, non-dust covered surface we obtain a water gas flux on the order of about 1.5×1028 molecules s?1 at perihelion, assuming a radius of 600 m. The calculated gas flux of water is within the order of measured values for comet 46P/Wirtanen. But our calculated values are maximum gas fluxes at noon—not averaged over one cometary day or taking the lesser insolation at the polar areas into account. Therefore, we conclude that either the radius of comet 46P/Wirtanen may be much larger than the accepted value of 600 m. A radius in the order of 2 km seems more likely to explain the measurements. Or, an other possibility could be that water-ice particles are blown off from the surface like dust particles. This may also increase the effective surface area of sublimation. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
