TY - JOUR
T1 - Corona-like atmospheric escape from KBOs. II. The behavior of aerosols
AU - Levi, Amit
AU - Podolak, Morris
N1 - Funding Information:
This work was supported, in part, by a grant from the Israel Academy of Sciences. We thank the referees, Dr. Chris McKay and Dr. Kevin Zahnle, for their very helpful comments which greatly contributed to improving this manuscript.
PY - 2009/10
Y1 - 2009/10
N2 - In Levi and Podolak (Levi, A., Podolak, M. [in press] Icarus) we applied the theory of coronal expansion to gas escape from a small, cold, object such as those found in the Kuiper belt. Here we extend the theory to include aerosols that are lifted off the surface by the escaping gas. Aerosols carried by the gas but still gravitationally bound, tend to be lifted to a height above the surface that is dependent on the aerosol radius, so that in steady state the variation of aerosol radius with height is well-defined. We develop an extension of Parker's coronal flow theory to include the effect of aerosols carried along by the gas and use this to estimate the optical depth of such an atmosphere. For KBOs with CO evaporation from the surface and with radii in the range 245-334 km, line-of-site optical depths through the atmosphere can exceed one at heights of a few hundred kilometers above the surface. Such aerosol layers should be observable, and might be used to infer the flow proprieties of the escaping gas.
AB - In Levi and Podolak (Levi, A., Podolak, M. [in press] Icarus) we applied the theory of coronal expansion to gas escape from a small, cold, object such as those found in the Kuiper belt. Here we extend the theory to include aerosols that are lifted off the surface by the escaping gas. Aerosols carried by the gas but still gravitationally bound, tend to be lifted to a height above the surface that is dependent on the aerosol radius, so that in steady state the variation of aerosol radius with height is well-defined. We develop an extension of Parker's coronal flow theory to include the effect of aerosols carried along by the gas and use this to estimate the optical depth of such an atmosphere. For KBOs with CO evaporation from the surface and with radii in the range 245-334 km, line-of-site optical depths through the atmosphere can exceed one at heights of a few hundred kilometers above the surface. Such aerosol layers should be observable, and might be used to infer the flow proprieties of the escaping gas.
KW - Atmospheres
KW - Dynamics
KW - Kuiper belt
KW - Trans-Neptunian objects
UR - http://www.scopus.com/inward/record.url?scp=69949091958&partnerID=8YFLogxK
U2 - 10.1016/j.icarus.2009.05.018
DO - 10.1016/j.icarus.2009.05.018
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AN - SCOPUS:69949091958
SN - 0019-1035
VL - 203
SP - 610
EP - 625
JO - Icarus
JF - Icarus
IS - 2
ER -