revised 11/98

1999 PACS, 90. - 99.

Summary of Scheme

91. Solid Earth Physics
91.10.-v Geodesy and gravity
91.10.By Mathematical geodesy; general theory
91.10.Da Cartography
91.10.Fc Space geodetic surveys
91.10.Jf Topography; geometric observations
91.10.Kg Crustal movements
91.10.Lh Photogrammetry
91.10.Nj Rotational variations; polar wobble
91.10.Qm Harmonics of the gravity potential field
***** Relations of gravity observations to tectonics and isostasy, see 91.45.S
91.10.Rn Rheology of lithosphere and mantle
91.10.Sp Satellite orbits
91.10.Tq Earth tides
91.10.Vr Ocean/Earth/atmosphere interaction
91.10.Ws Reference systems
91.25.-r Geomagnetism and paleomagnetism; geoelectricity
91.25.Cw Origins and models of the magnetic field; dynamo theories
91.25.Dx Archeomagnetism
91.25.Ey Interactions between exterior sources and interior properties
91.25.Ga Spatial variations: all harmonics and anomalies
91.25.Jc Spatial variations attributed to sea floor spreading
91.25.Le Time variations, diurnal to secular
91.25.Mf Reversals
91.25.Ng Paleomagnetism
91.25.Ph Magnetostratigraphy
91.25.Qi Geoelectricity; electromagnetic induction and conductivity (magnetotelluric effects)
91.30.-f Seismology
91.30.Bi Seismic sources (mechanisms, magnitude, moment frequency spectrum)
91.30.Dk Seismicity: space and time distribution
91.30.Fn Surface and body waves
91.30.Ks Free oscillations (periods less than 12 hours)
91.30.Mv Strong motions and shock waves
91.30.Nw Tsunamis (see also 92.10.D and 92.10.F for dynamics of the ocean)
91.30.Px Phenomena related to earthquake prediction
91.30.Rz Explosion seismology
91.30.Tb Volcano seismology
91.30.Vc Continental crust seismology
91.30.Ye Oceanic crust seismology
91.35.-x Earth's interior structure and properties
91.35.Cb Models of interior structure
91.35.Dc Heat flow; geothermy
91.35.Ed Structure of the Earth's interior below the upper mantle
91.35.Gf Structure of the crust and upper mantle
91.35.Lj Composition of Earth's interior
91.35.Nm Geochronology
91.35.Pn Tomography of the Earth's interior (see also 91.30 Seismology)
91.40.-k Volcanology
91.40.Bp Ash deposits
91.40.Dr Atmospheric effects (see also 92.60.M Particles and aerosols--in Meteorology)
91.40.Ft Eruptions
91.40.Hw Lava
91.45.-c Physics of plate tectonics
91.45.Cg Continental margins
91.45.Dh Plate tectonics
91.45.Ei Neotectonics
91.45.Fj Convection currents
91.45.Pt Slow vertical crustal movements (including isostasy and postglacial phenomena)
91.45.Qv Tomography of plate tectonics
91.45.Sx Relations of gravity observations to tectonics and isostasy
91.45.Ty Folds and Folding
91.45.Vz Fractures and faults
91.45.Yb Pluton emplacement
91.50.-r Marine geology and geophysics
91.50.Cw Beach, coastal, and shelf processes
91.50.Ey Ocean bottom processes (for ocean basin thermometry, see
43.30.Q in acoustics appendix)
91.50.Ga Bathymetry and noncoastal underwater morphology
91.50.Jc Turbidity currents, sedimentation (for acoustics of sediments, see 43.30.M in acoustics appendix)
91.60.-x Physical properties of rocks and minerals (for rheological properties of geological materials, see 83.50 and 83.80.N
91.60.Ba Elasticity, fracture, and flow
91.60.Dc Creep and deformation
91.60.Ed Crystal structure and defects
91.60.Fe Equations of state
91.60.Gf High-pressure behavior
91.60.Hg Phase changes
91.60.Ki Thermal properties
91.60.Lj Acoustic properties
91.60.Mk Optical properties
91.60.Pn Magnetic and electric properties
91.65.-n Geophysical aspects of geology, mineralogy, and petrology
91.65.Br Geochemical cycles
91.65.Dt Isotopic composition/chemistry
91.65.Fw Low-temperature geochemistry
91.65.Hy Organic geochemistry
91.65.Nd Trace elements
91.65.Rg Mineral occurrences and deposits
91.65.Ti Sedimentary petrology
91.65.Vj Major element composition
91.70.-c Information related to geologic time
91.70.Bf Cenozoic
91.70.Dh Mesozoic
91.70.Fj Paleozic
91.70.Hm Precambrian
91.90.+p Other topics in solid Earth physics (restricted to new topics in section 91)
92. Hydrospheric and Atmospheric Geophysics
92.10.-c Physics of the oceans (for ocean parameter estimation by acoustical methods, see
43.30.P in acoustics appendix)
92.10.Bf Physical properties of seawater
92.10.Cg Capillary waves
92.10.Dh Dynamics of the deep ocean
92.10.Ei Coriolis effects
92.10.Fj Dynamics of the upper ocean
92.10.Gk El Nino
92.10.Hm Surface waves, tides, and sea level
92.10.Jn Seiches
92.10.Kp Sea-air energy exchange processes
92.10.Lq Turbulence and diffusion
92.10.Mr Thermohaline structure and circulation
92.10.Ns Fine structure and microstructure
92.10.Pt Optical properties of sea water
92.10.Rw Sea ice
92.10.Sx Coastal and estuarine oceanography
92.10.Ty Fronts and jets
92.10.Vz Underwater sound (for acoustical aspects, see 43.30)
92.10.Wa Sediment transport
92.10.Yb Hydrography
***** Marine geology and geophysics, see 91.50
92.20.-h Interdisciplinary aspects of oceanography
92.20.Bk Aerosols
92.20.Cm Chemistry of the ocean
92.20.Gr Ocean energy extraction
92.20.Hs Anoxic environments
92.20.Jt Biological aspects of oceanography
92.20.Kv Photochemistry
92.20.Lw Photosynthesis
92.20.Mx Physicochemical properties
92.20.Ny Marine pollution
92.20.Pz Bacteria
92.20.Rb Plankton
92.20.Td Radioactivity
92.40.-t Hydrology and glaciology
92.40.Cy Modeling; general theory
92.40.Ea Precipitation
92.40.Fb Rivers, runoff, and streamflow
92.40.Gc Erosion and sedimentation
92.40.Je Evaporation
92.40.Kf Groundwater
92.40.Lg Soil moisture
92.40.Ni Limnology
92.40.Qk Water quality and water resources
92.40.Rm Snow
92.40.Sn Ice
92.40.Vq Glaciers
92.60.-e Meteorology (see also 43.28 Aeroacoustics and atmospheric sound, 42.68 Atmospheric optics, 94.10.D Atmospheric structure, pressure, density, and temperature)
92.60.Bh General circulation
92.60.Dj Gravity waves, tides, and compressional waves
92.60.Ek Convection, turbulence, and diffusion
92.60.Fm Boundary layer structure and processes
92.60.Gn Winds and their effects
92.60.Hp Chemical composition and chemical interactions
92.60.Jq Water in the atmosphere (humidity, clouds, evaporation, precipitation)
92.60.Ls Ionic interactions and processes
92.60.Mt Particles and aerosols (see also 94.20 Physics of the ionosphere)
92.60.Nv Cloud physics
92.60.Pw Atmospheric electricity
92.60.Qx Storms
92.60.Ry Climatology
92.60.Sz Air quality and air pollution
92.60.Ta Interaction of atmosphere with electromagnetic waves; propagation
92.60.Vb Solar radiation
92.60.Wc Weather analysis and prediction
92.70.-j Global change (see also 92.60 Meteorology)
92.70.Cp Atmosphere
92.70.Er Biogeochemical processes
92.70.Gt Climate dynamics
92.70.Jw Oceans
92.70.Ly Water cycles
92.90.+x Other topics in hydrospheric and atmospheric geophysics (restricted to new topics in section 92)
93. Geophysical Observations, Instrumentation, and Techniques
93.30.-w Information related to geographical regions
93.30.Bz Africa
93.30.Ca Antarctica
93.30.Db Asia
93.30.Fd Australia
93.30.Ge Europe
93.30.Hf North America
93.30.Jg South America
93.30.Kh Large islands (e.g., Greenland)
93.30.Li Arctic Ocean
93.30.Mj Atlantic Ocean
93.30.Nk Indian Ocean
93.30.Pm Pacific Ocean
93.30.Qn Southern Ocean
93.30.Rp Regional seas
93.30.Sq Polar regions
93.30.Tr Temperate regions
93.30.Vs Tropical regions
93.55.+z International organizations, national and international programs
93.65.+e Data acquisition and storage
93.85.+q Instrumentation and techniques for geophysical research
94. Aeronomy and Magnetospheric Physics
94.10.-s Physics of the neutral atmosphere (for atmospheres of the planets, see 99.35.H)
94.10.Bw General properties of the high atmosphere
94.10.Dy Atmospheric structure, pressure, density, and temperature (stratosphere, mesosphere, thermosphere, exosphere) (see also 92.60 Meteorology)
94.10.Fa Atmospheric composition (atomic or molecular), chemical reactions and processes (see also
82.40.W Atmospheric chemistry)
94.10.Gb Absorption and scattering of radiation
94.10.Jd Tides, waves, and winds
94.10.Lf Convection, diffusion, mixing, turbulence, and fallout
94.10.Nh Cosmic dust
94.10.Rk Aurora and airglow
94.20.-y Physics of the ionosphere (for ionospheres of the planets, see 98.35.K; for plasma physics aspects, see 52; for radiowave propagation, see 41.20.J in electromagnetism and 84.40 in electromagnetic technology)
94.20.Bb Wave propagation
94.20.Dd Ionospheric structure (D, E, F, and topside regions) including steady- state ion densities and temperatures
94.20.Ee D region
94.20.Gg E region
94.20.Ji F region
94.20.Kj Polar cap ionosphere
94.20.Lk Topside region
94.20.Mm Plasmasphere
94.20.Pp Plasmapause
94.20.Qq Particle precipitation
94.20.Rr Interactions between waves and particles
94.20.Ss Electric fields
94.20.Tt Ionospheric soundings
94.20.Vv Ionospheric disturbances
94.20.Ww Plasma motion, convection, or circulation
94.20.Yx Interaction between ionosphere and magnetosphere
94.30.-d Physics of the magnetosphere (for magnetospheres of the planets, see 98.35.K; for plasma physics aspects, see 52; for radiowave propagation, see 41.20.J in electromagnetism and 84.40 in electromagnetic technology)
94.30.Bg Magnetic coordinate systems
94.30.Ch Magnetospheric configuration
94.30.Di Magnetopause
94.30.Ej Magnetic tail
94.30.Fk Plasma motion, convection, or circulation
94.30.Gm Plasma instabilities
94.30.Hn Trapped particles
94.30.Jp Ring currents
94.30.Kq Electric fields
94.30.Lr Magnetic storms, substorms
94.30.Ms Magnetic pulsations
94.30.Tz Waves; propagation and excitation
94.30.Va Magnetosheath; interaction with interplanetary space (including solar wind) (for cosmic-ray interactions, see 13.85.T in elementary particle physics; see also 98.40 in solar system)
94.80.+g Instrumentation for aeronomy and magnetospheric studies (see also 95.55 Astronomical and space-research instrumentation)
94.90.+m Other topics in aeronomy and magnetospheric physics (restricted to new topics in section 94)
95. Fundamental Astronomy and Astrophysics; Instrumentation, Techniques, and Astronomical Observations
95.10.-a Fundamental astronomy
95.10.Ce Celestial mechanics (including n-body problems) (see also
03.20 Classical mechanics of discrete systems: general mathematical aspects)
***** Dynamics and kinematics of stellar systems, see 98.10
95.10.Eg Orbit determination and improvement
95.10.Fh Chaotic dynamics (see also 05.45 Theory and models of chaotic systems)
95.10.Gi Eclipses, transits, and occultations
95.10.Jk Astrometry and reference systems
95.10.Km Ephemerides, almanacs, and calendars
95.30.-k Fundamental aspects of astrophysics
95.30.Cq Elementary particle processes (see also 26 Nuclear astrophysics)
95.30.Dr Atomic processes and interactions (see also 32 Atomic properties and interactions with photons; 34 Atomic and molecular collision processes and interactions)
95.30.Ft Molecular and chemical processes and interactions; (see also 33 Molecular properties and interactions with photons; 34 Atomic and molecular collision processes and interactions)
95.30.Gv Radiation mechanisms; polarization
95.30.Jx Radiative transfer; scattering
95.30.Ky Atomic and molecular data, spectra, and spectral parameters (opacities, rotation constants, line identification, oscillator strengths, gf values, transition probabilities, etc.) (see also 32.10, 32.30, 32.70, 33.15, 33.20, and 33.70 in atomic and molecular physics)
95.30.Lz Hydrodynamics
95.30.Qd Magnetohydrodynamics and plasmas
95.30.Sf Relativity and gravitation (see also 04 General relativity and gravitation, 98.80.H Mathematical and relativistic cosmology)
95.30.Tg Thermodynamic processes, conduction, convection, equations of state (see also 05.70 Thermodynamics)
95.30.Wi Dust processes (condensation, evaporation, sputtering, mantle growth, etc.)
95.35.+d Dark matter (stellar, interstellar, galactic, and cosmological) (see also 95.30.C Elementary particle and nuclear processes; for brown dwarfs, see 97.20.V; for galactic halos see 98.35.G and 98.62.G; for models of the early Universe, see 97.10.F)
95.40.+s Artificial Earth satellites (for lunar and planetary probes, see 95.55.P)
95.45.+i Observatories
95.55.-n Astronomical and space-research instrumentation (see also 94.80 Instrumentation for aeronomy and magnetospheric studies, 07.87 spaceborne and space research instrument, apparatus, and components)
95.55.Aq Charge-coupled devices, image detectors, and IR detector arrays (see also 85.60.G Photodetectors)
95.55.Br Astrometric and interferometric instruments
95.55.Cs Ground-based ultraviolet, optical and infrared telescopes
95.55.Ev Solar instruments
95.55.Fw Space-based ultraviolet, optical, and infrared telescopes
95.55.Jz Radio telescopes and instrumentation; heterodyne receivers
95.55.Ka X- and gamma-ray telescopes and instrumentation
95.55.Pe Lunar, planetary, and deep-space probes
95.55.Qf Photometric, polarimetric, and spectroscopic instrumentation
95.55.Rg Photoconductors and bolometers (see also 07.57.K Bolometers, infrared submillimeter wave microwave and radiowave receivers and detectors)
95.55.Sh Auxiliary and recording instruments; clocks and frequency standards
95.55.Vj Neutrino, muon, pion, and other elementary particle detectors; cosmic ray detectors
95.55.Ym Gravitational radiation detectors; mass spectrometers; and other instrumentation and techniques (see also 04.80 Experimental studies of gravity in general relativity and gravitation)
95.75.-z Observation and data reduction techniques; computer modeling and simulation
95.75.De Photography and photometry (including microlensing techniques)
95.75.Fg Spectroscopy and spectrophotometry
95.75.Hi Polarimetry
95.75.Kk Interferometry
95.75.Mn Image processing (including source extraction)
95.75.Pq Mathematical procedures and computer techniques
95.75.Qr Adaptive and segmented optics (see also 42.68 Atmospheric optics)
95.75.Rs Remote observing techniques
95.75.Tv Digitization techniques (see also 07.05.P Image processing)
95.75.Wx Time series analysis, time variability
95.80.+p Astronomical catalogues, atlases, sky surveys, databases, retrieval systems, archives, etc.
95.85.-e Astronomical observations (additional primary heading(s) must be chosen with these entries to represent the astronomical objects and/or properties studied)
95.85.Bh Radio, microwave, and submillimeter
95.85.Fm Submillimeter (300 mum - 1 mm)
95.85.Gn Far infrared (10 - 300 mu m)
95.85.Hp Infrared (3 - 10 mu m)
95.85.Jq Near infrared (0.75 - 3 mu m)
95.85.Kr Visible (390 - 750 nm)
95.85.Ls Near ultraviolet (300 - 390 nm)
95.85.Mt Ultraviolet (10 - 300 nm)
95.85.Nv X-ray
95.85.Pw Gamma-ray
95.85.Ry Neutrino, muon, pion, and other elementary particles; cosmic rays
95.85.Sz Gravitational radiation, magnetic fields, and other observations
95.90.+v Historical astronomy and archaeoastronomy; and other topics in fundamental astronomy and astrophysics; instrumentation, techniques, and astronomical observations
96. Solar System (for the Earth, see 91-94)
96.10.+i General, solar nebula, and cosmogony
96.20.-n Moon
96.20.Br Origin, formation, and age
96.20.Dt Features, landmarks, mineralogy, petrology, and atmosphere
96.20.Jz Gravitational field, selenodesy, magnetic fields
96.20.Ka Cratering
96.30.-t Planets, their satellites and rings; asteroids ( for comets, see 96.50.G)
96.30.Dz Mercury
96.30.Ea Venus
96.30.Gc Mars
96.30.Kf Jupiter
96.30.Mh Saturn
96.30.Pj Uranus
96.30.Rm Neptune
96.30.Sn Pluto
96.30.Wr Planetary rings
96.30.Ys Asteroids (minor planets)
96.35.-j Planetary, asteroid, cometary, and satellite characteristics and properties (see also 97.82 for extrasolar planetary systems)
96.35.Cp Origin, formation, evolution, and ages
96.35.Er Chemical composition
96.35.Fs Mass, size; gravitational fields; rotation; orbits
96.35.Gt Surface features, cratering, and topography
96.35.Hv Neutral atmospheres
96.35.Kx Ionospheres; magnetospheres
96.35.Mz Interiors
96.35.Na Volcanism and tectonics
96.35.Pb Electric and magnetic fields
96.35.Se Interplanetary comparisons
96.40.-z Cosmic rays (for cosmic rays outside the Solar System, see 98.70.S)
96.40.Cd Interplanetary propagation and effects
96.40.De Composition, energy spectra, and interactions
96.40.Fg Energetic solar particles and photons
96.40.Kk Solar modulation and geophysical effects
96.40.Pq Extensive air showers
96.40.Tv Neutrinos and muons
96.40.Vw Cosmic-ray effects in meteorites and terrestrial matter
96.50.-e Interplanetary space (for asteroids, see 96.30.Y)
96.50.Bh Solar electric and magnetic fields (including solar wind fields)
96.50.Ci Solar wind plasma
96.50.Dj Interplanetary gas and dust (including gegenschein and zodiacal light)
96.50.Ek Solar wind interactions with planets, satellites, and comets (for interactions with Earth, see 94.30.V)
96.50.Fm Shock waves
96.50.Gn Comets
96.50.Hp Oort cloud
96.50.Jq Kuiper belt
96.50.Kr Meteors, meteoroids, and meteor streams
96.50.Mt Meteorites, micrometeorites, and tektites
96.50.Pw Particle acceleration
96.50.Qx Stream-stream interactions
96.50.Ry Waves and discontinuities
96.60.-j Solar physics
96.60.Bn Diameter, figure, rotation, mass
96.60.Fs Chemical composition
96.60.Hv Electric and magnetic fields
96.60.Jw Solar interior (for solar neutrinos, see
96.60.Ly Oscillations and waves; helioseismology
96.60.Mz Photosphere, granulation
96.60.Na Chromosphere and chromosphere-corona transition; spicules
96.60.Pb Corona; coronal loops, streamers, and holes
96.60.Qc Sunspots, faculae, plages
96.60.Rd Flares, bursts, and related phenomena
96.60.Se Prominences
96.60.Tf Solar electromagnetic radiation (see also 92.60.V Solar radiation in meteorology )
96.60.Vg Particle radiation, solar wind (see also 96.50.C Solar wind plasma and 96.50.E Solar wind interactions with planets, satellites, and comets)
96.60.Wh Coronal mass ejection
96.90.+c Other topics on the solar system (restricted to new topics in section 96)
97. Stars
97.10.-q Stellar characteristics and properties (see also
04.40.D Relativistic stars)
97.10.Bt Star formation
97.10.Cv Stellar structure, interiors, evolution, nucleosynthesis, ages
97.10.Ex Stellar atmospheres (photospheres, chromospheres, coronae, magnetospheres); radiative transfer; opacity and line formation
97.10.Fy Circumstellar shells, clouds, and expanding envelopes; circumstellar masers (for interstellar masers, see 98.38.E and 98.58.E)
97.10.Gz Accretion and accretion disks
97.10.Jb Stellar activity
97.10.Kc Stellar rotation
97.10.Ld Magnetic and electric fields; polarization of starlight
97.10.Me Mass loss and stellar winds
97.10.Nf Masses
97.10.Pg Radii
97.10.Qh Surface features (including starspots)
97.10.Ri Luminosities; magnitudes; effective temperatures, colors, and spectral classification
97.10.Sj Pulsations, oscillations, and stellar seismology
97.10.Tk Abundances, chemical composition
97.10.Vm Distances, parallaxes
97.10.Wn Proper motions and radial velocities (line-of-sight velocities); space motions (see also 95.10.J Astrometry and reference systems)
97.10.Xq Luminosity and mass functions
97.10.Yp Star counts, distribution, and statistics
97.10.Zr Hertzsprung-Russell, color-magnitude, and color-color diagrams
97.20.-w Normal stars (by class): general or individual
97.20.Ec Main-sequence: early-type stars (O and B)
97.20.Ge Main-sequence: intermediate-type stars (A and F)
97.20.Jg Main-sequence: late-type stars (G, K, and M)
97.20.Li Giant and subgiant stars
97.20.Pm Supergiant stars
97.20.Rp Faint blue stars (including blue stragglers), white dwarfs, degenerate stars, nuclei of planetary nebulae (for planetary nebulae, see 98.38.L or 98.58.L)
97.20.Tr Population II stars (horizontal branch, metal poor, etc.)
97.20.Vs Low luminosity stars, subdwarfs, and brown dwarfs
97.20.Wt Population III stars
97.21.+a Pre-main sequence objects, young stellar objects (YSO's) and protostars (T Tauri stars, Orion population, Herbig-Haro objects, Bok globules, bipolar outflows, cometary nebulae, etc.) (see also 98.38.F and 98.58.F Jets, outflows and bipolar flows in the Milky Way and external galaxies)
97.30.-b Variable and peculiar stars (including novae)
97.30.Dg Low-amplitude blue variables (alpha Cygni, beta Cephei, delta Scuti, delta Delphini, delta Canis Majoris, SX Phoenicius, etc.)
97.30.Eh Emission-line stars (Of, Be, Luminous Blue Variables, Wolf-Rayet, etc.)
97.30.Fi Chemically peculiar stars (Ap, Am, etc.)
97.30.Gj Cepheids (delta Cephei, W Virginis)
97.30.Hk Carbon stars, S stars, and related types (C, S, R, and N)
97.30.Jm Long-period variables (Miras) and semiregulars
97.30.Kn RR Lyrae stars, RV Tauri and PV Telescopii variables
97.30.Nr Flare stars (UV Ceti, RS Canum Venaticorum, FU Orionis, R Coronae Borealis variables, etc.)
97.30.Qt Novae, dwarf novae, recurrent novae, and other cataclysmic (eruptive) variables (see also 97.80.G, J Cataclysmic binaries and X-ray binaries)
97.30.Sw Unusual and peculiar variables
97.60.-s Late stages of stellar evolution (including black holes) (see also 04.40.D Relativistic stars)
97.60.Bw Supernovae
97.60.Gb Pulsars
97.60.Jd Neutron stars
97.60.Lf Black holes (see also 04.70 Physics of black holes, 95.30.S Relativity and gravitation; for galactic black holes, see 98.35.J and 98.62.J; for infall, accretion, and accretion disks, see 98.62.M )
97.80.-d Binary and multiple stars
97.80.Af Astrometric and interferometric binaries
97.80.Di Visual binaries
97.80.Fk Spectroscopic binaries; close binaries
97.80.Gm Cataclysmic binaries (novae, dwarf novae, recurrent novae, and nova- like objects); symbiotic stars (see also 97.30.Q Novae)
97.80.Hn Eclipsing binaries
97.80.Jp X-ray binaries (see also 98.70.Q X-ray sources; see also 97.60.G Pulsars)
97.80.Kq Multiple stars
97.82.-j Extrasolar planetary systems
97.82.Cp Photometric and spectroscopic detection; coronographic detection; interferometric detection
97.82.Fs Substellar companions; planets
97.82.Jw Infrared excess; debris disks; protoplanetary disks; exo-zodiacal dust
97.90.+j Other topics on stars (restricted to new topics in section 97)
98. Stellar Systems; Interstellar Medium; Galactic and Extragalactic Objects and Systems; the Universe
98.10.+z Stellar dynamics and kinematics
98.20.-d Stellar clusters and associations
98.20.Af Associations of stars (OB, T, R) in the Milky Way
98.20.Bg Associations of stars (OB, T, R) in external galaxies
98.20.Di Open clusters in the Milky Way
98.20.Fk Open clusters in external galaxies
98.20.Gm Globular clusters in the Milky Way
98.20.Jp Globular clusters in external galaxies
98.35.-a Characteristics and properties of the Milky Way galaxy
98.35.Ac Origin, formation, evolution, age, and star formation
98.35.Bd Chemical composition and chemical evolution
98.35.Ce Mass and mass distribution
98.35.Df Kinematics, dynamics, and rotation
98.35.Eg Electric and magnetic fields
98.35.Gi Galactic halo
98.35.Hj Spiral arms and galactic disk
98.35.Jk Galactic center, bar, circumnuclear matter, and bulge (including black hole and distance measurements) (see also
04.70 Physics of black holes)
98.35.Ln Stellar content and populations; morphology and overall structure
98.35.Mp Infall and accretion
98.35.Nq Galactic winds and fountains
98.35.Pr Solar neighborhood
98.38.-j Interstellar medium (ISM) and nebulae in Milky Way
98.38.Am Physical properties (abundances, electron density, magnetic fields, scintillation, scattering, kinematics, dynamics, turbulence, etc.)
98.38.Bn Atomic, molecular, and chemical, and grain processes
98.38.Cp Interstellar dust grains; diffuse emission; infrared cirrus
98.38.Dq Molecular clouds, H sub 2 clouds, dense clouds, and dark clouds
98.38.Er Interstellar masers (for circumstellar masers, see 97.10.F )
98.38.Fs Jets, outflows, and bipolar flows (for pre-main sequence objects, see 97.21)
98.38.Gt H I regions and 21-cm lines; diffuse, translucent, and high-velocity clouds
98.38.Hv H II regions; emission and reflection nebulae
98.38.Jw Infrared emission
98.38.Kx Intercloud medium (ICM); hot and highly ionized gas; bubbles
98.38.Ly Planetary nebulae (for nuclei of planetary nebulae, see also 97.20.R)
98.38.Mz Supernova remnants
98.52.-b Normal galaxies; extragalactic objects and systems (by type)
98.52.Cf Classification and classification systems
98.52.Eh Elliptical galaxies
98.52.Lp Lenticular (SO) galaxies
98.52.Nr Spiral galaxies
98.52.Sw Irregular and morphologically peculiar galaxies
98.52.Wz Dwarf galaxies (elliptical, irregular, and spheroidal)
98.54.-h Quasars; active or peculiar galaxies, objects, and systems
98.54.Aj Quasars
98.54.Cm Active and peculiar galaxies (including BL Lacertae objects, blazers, Seyfert galaxies, Markarian galaxies, active galactic nuclei)
98.54.Ep Starburst galaxies and infrared excess galaxies
98.54.Gr Radio galaxies
98.54.Kt Protogalaxies; primordial galaxies
98.56.-p Local group; Magellanic clouds
98.56.Ew Elliptical galaxies
98.56.Ne Spiral galaxies (M31 and M33)
98.56.Si Magellanic clouds and other irregular galaxies
98.56.Tj Magellanic stream
98.56.Wm Dwarf galaxies (elliptical, irregular, and spheroidal)
98.58.-w Interstellar medium (ISM) and nebulae in external galaxies
98.58.Ay Physical properties (abundances, electron density, magnetic fields, scintillation, scattering, kinematics, dynamics, turbulence, etc.
98.58.Bz Atomic, molecular, chemical, and grain processes
98.58.Ca Interstellar dust grains; diffuse emission; infrared cirrus
98.58.Db Molecular clouds, H sub 2 clouds, dense clouds, and dark clouds
98.58.Ec Interstellar masers (for circumstellar masers, see 97.10.F)
98.58.Fd Jets, outflows, and bipolar flows (for pre-main sequence objects, see 97.21)
98.58.Ge H I regions and 21-cm lines; diffuse, translucent, and high-velocity clouds
98.58.Hf H II regions; emission and reflection nebulae
98.58.Jg Infrared emission
98.58.Kh Intercloud medium (ICM); hot and highly ionized gas; bubbles
98.58.Li Planetary nebulae (for nuclei of planetary nebulae, see also 97.20.R)
98.58.Mj Supernova remnants
98.58.Nk Tidal tails; HI shells
98.62.-g Characteristics and properties of external galaxies and extragalactic objects (for the Milky Way, see 98.35)
98.62.Ai Origin, formation, evolution, age, and star formation
98.62.Bj Chemical composition and chemical evolution
98.62.Ck Masses and mass distribution
98.62.Dm Kinematics, dynamics, and rotation
98.62.En Electric and magnetic fields
98.62.Gq Galactic halos
98.62.Hr Spiral arms and bars; galactic disks
98.62.Js Galactic nuclei (including black holes), circumnuclear matter, and bulges (see also 04.70 Physics of black holes)
98.62.Lv Stellar content and populations; radii; morphology and overall structure
98.62.Mw Infall, accretion, and accretion disks (see also 04.70 Physics of black holes)
98.62.Nx Jets and bursts; galactic winds and fountains
98.62.Py Distances, redshifts, radial velocities; spatial distribution of galaxies (see also 98.80.E Observational cosmology)
98.62.Qz Magnitudes and colors; luminosities
98.62.Ra Intergalactic matter; quasar absorption and emission-line systems; Lyman forest (for quasars see 98.54.A; for intracluster matter see 98.65.H)
98.62.Sb Gravitational lenses and luminous arcs (see also 95.30.S Relativity and gravitation)
98.62.Tc Astrometry; identification
98.62.Ve Statistical and correlative studies of properties (luminosity and mass functions; mass-to-light ratio; Tully-Fisher relation, etc.)
98.65.-r Galaxy groups, clusters, and superclusters; large scale structure of the Universe
98.65.At Interacting galaxies; galaxy pairs, and triples
98.65.Bv Small and compact galaxy groups
98.65.Cw Galaxy clusters
98.65.Dx Superclusters; large-scale structure of the Universe (including voids, pancakes, great wall, etc.)
98.65.Fz Galaxy mergers, collisions, and tidal interactions
98.65.Hb Intracluster matter; cooling flows
98.70.-f Unidentified sources of radiation outside the Solar System (for cosmic rays in the Solar System, see 96.40; for pulsars, see 97.60.G)
98.70.Dk Radio sources
***** Quasars, see 98.54.A
98.70.Lt IR sources (for IR sources in interstellar medium, see 98.38.J and/or 98.58.J)
98.70.Qy X-ray sources; X-ray bursts (see also 97.30.Q Novae, dwarf novae, 97.80.J X-ray binaries)
98.70.Rz Gamma-ray sources; gamma-ray bursts
98.70.Sa Cosmic-rays (including sources, origin, acceleration, and interactions)
98.70.Vc Background radiations
98.80.-k Cosmology (see also 04 General relativity and gravitation; for origin and evolution of galaxies, see 98.62.A; for elementary particle and nuclear processes, see 95.30.C; for dark matter, see 95.35; for superclusters and large-scale structure of the Universe, see 98.65.D)
98.80.Bp Origin and formation of the Universe
98.80.Cq Particle-theory and field-theory models of the early Universe (including cosmic pancakes, cosmic strings, chaotic phenomena, inflationary universe, etc.)
98.80.Es Observational cosmology (including Hubble constant, distance scale, cosmological constant, early Universe, etc)
98.80.Ft Origin, formation, and abundances of the elements (see also 26.35 Big Bang nucleosynthesis)
98.80.Hw Mathematical and relativistic aspects of cosmology; quantum cosmology (see also 95.30.S Relativity and gravitation)
98.90.+s Other topics on stellar systems; interstellar medium; galactic and extragalactic objects and systems; the Universe (restricted to new topics in section 98)
99.10.+g Errata