TY - JOUR
T1 - Corona-like atmospheric escape from KBOs. I. Gas dynamics
AU - Levi, Amit
AU - Podolak, Morris
N1 - Funding Information:
We thank Dr. K. Zahnle for a careful initial reading of the manuscript, and Dr. D. Hunten and an anonymous referee for helpful suggestions on how this manuscript could be improved. This work was supported, in part, by the France–Israel Research Networks Program in Astrophysics.
PY - 2009/8
Y1 - 2009/8
N2 - We show that for low temperatures (T ∼ 30 K) and small, but non-negligible, gravitational fields the hydrodynamic escape of gas can be treated by Parker's theory of coronal expansion [Parker, E.N., 1963. Interplanetary Dynamical Processes. Interscience Publishers, New York]. We apply this theory to gas escape from Kuiper belt objects. We derive limits on the density and radius of the bodies for which this theory is applicable, and show how the flow depends on the mean molecular weight and internal degrees of freedom of the gas molecules. We use these results to explain the CH4 dichotomy seen on KBOs [Schaller, E.L., Brown, M.E., 2007. Astrophys. J., 659, L61-L64].
AB - We show that for low temperatures (T ∼ 30 K) and small, but non-negligible, gravitational fields the hydrodynamic escape of gas can be treated by Parker's theory of coronal expansion [Parker, E.N., 1963. Interplanetary Dynamical Processes. Interscience Publishers, New York]. We apply this theory to gas escape from Kuiper belt objects. We derive limits on the density and radius of the bodies for which this theory is applicable, and show how the flow depends on the mean molecular weight and internal degrees of freedom of the gas molecules. We use these results to explain the CH4 dichotomy seen on KBOs [Schaller, E.L., Brown, M.E., 2007. Astrophys. J., 659, L61-L64].
KW - Abundances
KW - Kuiper belt
KW - Trans-neptunian objects
KW - atmospheres
UR - http://www.scopus.com/inward/record.url?scp=67649980032&partnerID=8YFLogxK
U2 - 10.1016/j.icarus.2009.03.004
DO - 10.1016/j.icarus.2009.03.004
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AN - SCOPUS:67649980032
SN - 0019-1035
VL - 202
SP - 681
EP - 693
JO - Icarus
JF - Icarus
IS - 2
ER -