Essential Radio Astronomy

386 Pages·2016·33.51 MB·English

by  James J. Condon, Scott M. Ransom

Essential Radio Astronomy
PRINCETONSERIESINMODERNOBSERVATIONALASTRONOMY
DavidN.Spergel,SERIES EDITOR
Written by some of the world’s leading astronomers, the Princeton Series in Modern
ObservationalAstronomyaddressestheneedsandinterestsofcurrentandfutureprofes-
sional astronomers. International in scope, the series includes cutting-edge monographs
andtextbooksontopicsgenerallyfallingunderthecategoriesofwavelength,observational
techniques and instrumentation, and observational objects from a multiwavelength
perspective.
Statistics, Data Mining, and Machine Learning in Astronomy: A Practical Python Guide for the
AnalysisofSurveyData,byŽeljkoIvezic´,AndrewJ.Connolly,JacobT.VanderPlas,andAlexander
Gray
Essential Radio Astronomy
James J. Condon and Scott M. Ransom
PRINCETON UNIVERSITY PRESS • PRINCETON AND OXFORD
Copyright(cid:2)c 2016byPrincetonUniversityPress
PublishedbyPrincetonUniversityPress,41WilliamStreet,
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IntheUnitedKingdom:PrincetonUniversityPress,6OxfordStreet,
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ISBN978-0-691-13779-7
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10 9 8 7 6 5 4 3 2 1
Contents
Preface ix
1 Introduction 1
1.1 AnIntroductiontoRadioAstronomy 1
1.2 TheDiscoveryofCosmicRadioNoise 9
1.3 ATouroftheRadioUniverse 15
2 RadiationFundamentals 23
2.1 BrightnessandFluxDensity 23
2.2 RadiativeTransfer 30
2.3 Polarization 40
2.4 BlackbodyRadiation 42
2.5 NoiseGeneratedbyaWarmResistor 50
2.6 CosmicMicrowaveBackgroundRadiation 53
2.7 RadiationfromanAcceleratedCharge 58
2.8 DustEmissionatRadioWavelengths 61
3 RadioTelescopesandRadiometers 64
3.1 AntennaFundamentals 64
3.2 ReflectorAntennas 80
3.3 Two-DimensionalApertureAntennas 92
3.4 Waveguides 100
3.5 RadioTelescopes 102
3.6 Radiometers 112
3.7 Interferometers 126
4 Free-FreeRadiation 141
4.1 ThermalandNonthermalEmission 141
4.2 HIIRegions 141
4.3 Free–FreeRadioEmissionfromHIIRegions 146
5 SynchrotronRadiation 160
5.1 Magnetobremsstrahlung 160
5.2 SynchrotronPower 163
5.3 SynchrotronSpectra 167
5.4 SynchrotronSources 178
5.5 Inverse-ComptonScattering 188
5.6 ExtragalacticRadioSources 194
vi • Contents
6 Pulsars 208
6.1 PulsarProperties 208
6.2 PulsarsandtheInterstellarMedium 222
6.3 PulsarTiming 225
7 SpectralLines 233
7.1 Introduction 233
7.2 RecombinationLines 234
7.3 LineRadiativeTransfer 242
7.4 ExcitationTemperature 247
7.5 Masers 249
7.6 RecombinationLineSources 252
7.7 MolecularLineSpectra 255
7.8 TheHI21-cmLine 266
A FourierTransforms 277
A.1 TheFourierTransform 277
A.2 TheDiscreteFourierTransform 278
A.3 TheSamplingTheorem 280
A.4 ThePowerSpectrum 282
A.5 BasicTransforms 282
A.6 BasicFourierTheorems 282
A.7 ConvolutionandCross-Correlation 284
A.8 OtherFourierTransformLinks 286
B MathematicalDerivations 287
B.1 EvaluationofPlanck’sSum 287
B.2 DerivationoftheStefan–BoltzmannLaw 288
B.3 ComplexExponentials 291
B.4 TheFourierTransformofaGaussian 293
B.5 TheGaussianProbabilityDistributionandNoiseVoltage 294
B.6 TheProbabilityDistributionofNoisePower 295
B.7 EvaluationoftheFree–FreePulseEnergyIntegral 296
B.8 TheNonrelativisticMaxwellianSpeedDistribution 297
C SpecialRelativity 299
C.1 Relativity 299
C.2 TimeDilationandLengthContraction 302
C.3 VelocityAdditionFormulas 302
C.4 Mass,Energy,andPower 303
D WavePropagationinaPlasma 305
D.1 DispersionandReflectioninaLow-DensityPlasma 305
D.2 FaradayRotationinaMagnetizedPlasma 307
Contents • vii
E EssentialEquations 309
F Constants,Units,andDimensions 332
F.1 PhysicalConstants 332
F.2 AstronomicalConstants 332
F.3 MKS(SI)andGaussianCGSUnits 333
F.4 OtherConstantsandUnits 336
F.5 RadarandWaveguideFrequencyBands 336
F.6 DimensionalAnalysis 337
G SymbolsandAbbreviations 338
G.1 GreekSymbols 338
G.2 OtherSymbolsandAbbreviations 340
H ReferencesandLinks 348
H.1 ReferenceBooks 348
H.2 Links 349
Bibliography 351
Index 357