Trans-Neptunian Objects and Comets: Saas-Fee Advanced Course 35. Swiss Society for Astrophysics and Astronomy (Saas-Fee Advanced Courses)

267 Pages·2007·5.17 MB·English

by  David Jewitt

Saas-Fee AdvancedCourse35
D. Jewitt A. Morbidelli H. Rauer
Trans-Neptunian Objects
and Comets
Saas-Fee Advanced Course 35
Swiss Society for Astrophysics and Astronomy
Edited by K. Altwegg, W. Benz and N. Thomas
With132 Figures,18 inColor
DavidJewitt HeikeRauer
UniversityofHawaii DLR/InstitutfürPlanetenforschung
InstituteforAstronomy Rutherfordstr.2
2680WoodlawnDrive 12489Berlin,Germany
Honolulu,HI96822,USA and
[email protected] TUBerlin/Zentrum
fürAstronomieundAstrophysik
AlessandroMorbidelli Hardenbergstr.36
10623Berlin,Germany
ObservatoiredelaCôte [email protected]
dŠAzur/CNRS
B.P.4229
06304NiceCedex4,France
[email protected]
VolumeEditors:
KathrinAltwegg
WillyBenz
NicolasThomas
UniversitätBern
PhysikalischesInstitut
Sidlerstrasse5
3012Bern,Switzerland
ThisseriesiseditedonbehalfoftheSwissSocietyforAstrophysicsandAstronomy:
SociétéSuissed’Astrophysiqueetd’Astronomie
ObservatoiredeGenève,ch.desMaillettes51,1290Sauverny,Switzerland
Coverpicture:SeechapterbyD.Jewitt,Fig.12.
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ISBN978-3-540-71957-1 SpringerBerlinHeidelbergNewYork
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Preface
The 35th Saas Fee Winter School was held on 13–18 March 2005 in the
skiing village of Mu¨rren in the Berner Oberland. In view of the excitement
generated over the past 15 years by the discovery of the Kuiper Belt and
Trans-Neptunian Objects and also by the ongoing Rosetta mission to comet
Churyumov-Gerasimenko,itwasdecidedtocombinediscussionoftheseprim-
itiveobjectsintoonewinterschoolunderthetitle,“Trans-NeptunianObjects
andComets.”Theaimwastoprovideanoverviewoftheseobjects,todiscuss
their relationships, and to identify directions for future research. The school
attracted over 60 students from all over the world. We were fortunate that
not merely were the students able to hear a set of outstanding lectures but
were also able to enjoy marvellous weather in one of the most beautiful parts
of Switzerland.
The organizers thank the lecturers, Dave Jewitt, Alessandro Morbidelli,
and Heike Rauer, for the tremendous effort they made in preparing the
lectures and the text for this volume. Stephan Graf, Annette Ja¨ckel, and
Jonathan Horner provided reviews, checked the text and references, and as-
sistedintheproduction.WealsothankFrauStaehliandthestaffoftheHotel
Eiger in Mu¨rren for the warm welcome and their generosity. We also thank
Ms.KathrinWeyenethandMs.EdithHertigfromthe PhysikalischesInstitut
for their secretarialsupport for the school.
Financial assistance provided by the Swiss Society for Astrophysics and
Astronomy and the European Space Agency is gratefully acknowledged.
Kathrin Altwegg
Willy Benz
Nicolas Thomas
Contents
Kuiper Belt and Comets: An Observational Perspective
D. Jewitt ....................................................... 1
1 Preamble.................................................... 1
1.1 The Conduct of Research into the Subject .................. 2
2 The Modern Solar System ..................................... 5
2.1 Protoplanetary Disk ..................................... 5
2.2 The Three Domains...................................... 9
3 Cometary Nuclei ............................................. 26
3.1 Mantles ................................................ 38
4 Kuiper Belt.................................................. 47
4.1 Kuiper Belt Physical Properties: Colors and Albedos ......... 47
4.2 Kuiper Belt Physical Properties: Spectra.................... 53
4.3 Kuiper Belt Physical Properties: Shapes, Spins .............. 56
4.4 Kuiper Belt Physical Properties: Multiple Objects ........... 57
4.5 Kuiper Belt Physical Properties: Densities .................. 59
4.6 Centaurs ............................................... 62
4.7 Irregular Satellites ....................................... 63
4.8 Trojans................................................. 68
References ...................................................... 72
Comets and Their Reservoirs: Current Dynamics
and Primordial Evolution
A. Morbidelli.................................................... 79
1 The Trans-Neptunian Population............................... 80
1.1 Brief Tutorial on Orbital Dynamics ........................ 80
1.2 The Structure of the Trans-Neptunian Population............ 84
1.3 Dynamics in the Kuiper Belt.............................. 93
1.4 Note on the Scattered Disk ...............................100
2 The Dynamics of Comets......................................101
2.1 Origin and Evolution of Jupiter Family Comets..............104
2.2 Origin and Evolution of Long-PeriodComets................108
VIII Contents
2.3 Note on Halley-Type Comets..............................113
2.4 The Fate of Faded Comets ................................115
3 The Formation of the Oort Cloud ..............................117
3.1 Problems with the Classical Scenario.......................122
3.2 Oort Cloud Formation in a Dense Galactic Environment......124
4 The Primordial Sculpting of the Kuiper Belt.....................127
4.1 The Origin of the Resonant Populations ....................128
4.2 The Origin of the Hot Population..........................130
4.3 The Origin of the Outer Edge of the Kuiper Belt ............132
4.4 The Mass Deficit of the Cold Population....................134
4.5 Pushing out the Kuiper Belt ..............................138
5 Origin of the Late Heavy Bombardment
of the Terrestrial Planets ......................................139
6 Building a Coherent View of Solar System History: Perspectives
for Future Work..............................................151
References ......................................................154
Comets
H. Rauer .......................................................165
1 Introduction .................................................165
2 Sublimation Processes ........................................168
2.1 General Overview........................................168
2.2 Gas Sublimation and Nucleus Differentiation ................170
2.3 Observations of Gas Activity Evolution.....................175
3 Coma and Tail Dynamics .....................................182
3.1 Dynamics of the Neutral Coma ...........................182
3.2 Dynamics in the Outer Coma and Neutral Gas Tails .........200
3.3 Dynamics of Dust Tails ..................................201
3.4 Dynamics of Ion Tails ...................................204
4 Emission Excitation in the Gas Coma ..........................208
4.1 Resonance Fluorescence ..................................212
4.2 Prompt Emission ........................................213
4.3 Optical Depth Effects ....................................214
4.4 Excitation of Rotational and Vibrational Transitions .........214
4.5 OH Maser Emission......................................216
4.6 X-ray Emission..........................................216
5 Chemical Processes in the Coma ...............................216
5.1 Chemistry of Some Frequently Observed Species .............219
6 Gas Production Rates ........................................224
6.1 Simple Coma Models.....................................224
6.2 Abundance Ratios and Compositional
Differences among Comets ................................226
6.3 Compositional Differences Among Comets ..................230
6.4 Isotopic Ratios ..........................................231
Contents IX
7 Dust Particles ...............................................233
7.1 Composition ............................................234
7.2 Size Distribution.........................................236
7.3 The Dust Production Rate................................238
8 Outlook.....................................................240
References ......................................................242
Acknowledgments .............................................255
Index..........................................................257
List of Previous Saas-Fee Advanced Courses
!! 2005 Trans-NeptunianObjectsand Comets
D. Jewitt, A. Morbidelli, H. Rauer
!! 2004 TheSun,Solar Analogs andtheClimate
J.D. Haigh, M. Lockwood, M.S. Giampapa
!! 2003 Gravitation Lensing: Strong, WeakandMicro
P. Schneider, C. Kochanek, J. Wambsganss
!! 2002 TheCold Universe
A.W. Blain, F. Combes, B.T. Draine
!! 2001 Extrasolar Planets
T. Guillot, P. Cassen, A. Quirrenbach
!! 2000 High-Energy SpectroscopicAstrophysics
S.M. Kahn, P. von Ballmoos, R.A. Sunyaev
!! 1999 PhysicsofStar Formation in Galaxies
F. Palla, H. Zinnecker
!! 1998 StarClusters
B.W. Carney, W.E. Harris
!! 1997 Computational MethodsforAstrophysical FluidFlow
R.J. LeVeque, D. Mihalas, E.A. Dorfi, E. Mu¨ller
!! 1996 Galaxies Interactions andInducedStarFormation
R.C. Kennicutt, F. Schweizer, J.E. Barnes
!! 1995 Stellar Remnants
S.D. Kawaler, I. Novikov, G. Srinivasan
!! 1994 Plasma Astrophysics
J.G. Kirk, D.B. Melrose, E.R. Priest
!! 1993 TheDeepUniverse
A.R. Sandage, R.G. Kron, M.S. Longair
!! 1992 Interacting Binaries
S.N. Shore, M. Livio, E.J.P. van den Heuvel
!! 1991 TheGalactic Interstellar Medium
W.B. Burton, B.G. Elmegreen, R. Genzel
!! 1990 Active Galactic Nuclei
R. Blandford, H. Netzer, L. Woltjer
* 1989 TheMilky WayasaGalaxy
G. Gilmore, I. King, P. van der Kruit
! 1988 Radiation inMoving GaseousMedia
H. Frisch, R.P. Kudritzki, H.W. Yorke
! 1987 LargeScaleStructuresintheUniverse
A.C. Fabian, M. Geller, A. Szalay
! 1986 Nucleosynthesis andChemical Evolution
J. Audouze, C. Chiosi, S.E. Woosley
! 1985 HighResolution inAstronomy
R.S. Booth, J.W. Brault, A. Labeyrie
! 1984 Planets, TheirOrigin, InteriorandAtmosphere
D. Gautier, W.B. Hubbard, H. Reeves
! 1983 Astrophysical ProcessesinUpperMainSequenceStars
A.N. Cox, S. Vauclair, J.P. Zahn
* 1982 Morphology andDynamics ofGalaxies
J. Binney, J. Kormendy, S.D.M. White
! 1981 Activity andOuterAtmospheres oftheSunandStars
F. Praderie, D.S. Spicer, G.L. Withbroe
* 1980 StarFormation
J. Appenzeller, J. Lequeux, J. Silk
* 1979 Extragalactic High EnergyPhysics
F. Pacini, C. Ryter, P.A. Strittmatter
* 1978 Observational Cosmology
J.E. Gunn, M.S. Longair, M.J. Rees
* 1977 AdvancedStages in Stellar Evolution
I. Iben Jr., A. Renzini, D.N. Schramm
* 1976 Galaxies
K. Freeman, R.C. Larson, B. Tinsley
* 1975 Atomic andMolecular ProcessesinAstrophysics
A. Dalgarno, F. Masnou-Seeuws, R.V.P. McWhirter
* 1974 Magnetohydrodynamics
L. Mestel, N.O. Weiss
* 1973 Dynamical StructureandEvolution ofStellar Systems
G. Contopoulos, M. H´enon, D. Lynden-Bell
* 1972 Interstellar Matter
N.C. Wickramasinghe, F.D. Kahn, P.G. Metzger
* 1971 TheoryoftheStellar Atmospheres
D. Mihalas, B. Pagel, P. Souffrin
* Outofprint
! MaybeorderedfromGenevaObservatory
Saas-FeeCourses
GenevaObservatory
CH-1290 Sauverny
Switzerland
!! MaybeorderedfromSpringer and/or are available online
at springerlink.com.