IntroductiontoAstronomicalSpectroscopy SpectroscopyistheprincipaltoolusedinastronomytoinvestigatetheUniversebeyond Earth’satmosphere.Throughtheanalysisofelectromagneticradiation,spectrographs enable observers to assess the chemical composition, kinematics, and local physical properties of distant stars, nebulae, and galaxies. Thoroughly illustrated and clearly written, this handbook offers a practical and comprehensive guide to the different spectroscopic methods used in all branches of astronomy, at all wavelengths from radiotogamma-ray,andfromgroundandspace-borneinstruments.Afterahistorical overviewofthefield,thecentralchaptersnavigatethevarioustypesofhardwareused in spectroscopy. In-depth descriptions of modern techniques and their benefits and drawbacks help you choose the most promising observation strategy. The handbook finishesbyassessingnewtechnologiesandfutureprospectsfordeep-skyobservation. Thistextisanidealreferencefortoday’sgraduatestudentsandactiveresearchers,as wellasthosedesigningoroperatingspectroscopicinstruments. immo appenzeller is Emeritus Professor of Astronomy at the University of Heidelberg,Germany,andDirectoroftheHeidelbergStateObservatory. Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:52:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503 Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:52:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503 CambridgeObservingHandbooksforResearchAstronomy Today’sprofessionalastronomersmustbeabletoadapttousetelescopesand interpretdataatallwavelengths.Thisseriesisdesignedtoprovidethemwith acollectionofconcise,self-containedhandbooks,whichcoversthebasicprin- ciplespeculiartoobservinginaparticularspectraregion,ortousingaspecial techniqueortypeofinstrument.Thebookscanbeusedasanintroductionto thesubjectandasahandyreferenceforuseatthetelescopeorintheoffice. Serieseditors Professor Richard Ellis, Department of Astronomy, California Institute of Technology ProfessorSteveKahn,DepartmentofPhysics,StanfordUniversity ProfessorGeorgeRieke,StewardObservatory,UniversityofArizona,Tuscon Dr Peter B. Stetson, Herzberg Institute of Astrophysics, Dominion Astro- physicalObservatory,Victoria,BritishColumbia Bookscurrentlyavailableinthisseries: 1. HandbookofInfraredAstronomy I.S.Glass 4. HandbookofPulsarAstronomy D.R.LorimerandM.Kramer 5. HandbookofCCDAstronomy,SecondEdition SteveB.Howell 6. IntroductiontoAstronomicalPhotometry,SecondEdition EdwinBuddingandOsmanDemircan 7. HandbookofX-rayAstronomy EditedbyKeithArnaud,RandallSmith,andAnetaSiemiginowska 8. PracticalStatisticsforAstronomers,SecondEdition J.V.WallandC.R.Jenkins 9. IntroductiontoAstronomicalSpectroscopy ImmoAppenzeller Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:52:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503 Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:52:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503 Introduction to Astronomical Spectroscopy IMMO APPENZELLER CenterforAstronomy UniversityofHeidelberg Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:52:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503 cambridgeuniversitypress Cambridge,NewYork,Melbourne,Madrid,CapeTown, Singapore,Sa˜oPaulo,Delhi,MexicoCity CambridgeUniversityPress 32AvenueoftheAmericas,NewYork,NY10013-2473,USA www.cambridge.org Informationonthistitle:www.cambridge.org/9781107601796 ©ImmoAppenzeller2013 Thispublicationisincopyright.Subjecttostatutoryexception andtotheprovisionsofrelevantcollectivelicensingagreements, noreproductionofanypartmaytakeplacewithoutthewritten permissionofCambridgeUniversityPress. Firstpublished2013 PrintedintheUnitedStatesofAmerica AcatalogrecordforthispublicationisavailablefromtheBritishLibrary. LibraryofCongressCataloginginPublicationdata Appenzeller,I.(Immo),1940– Introductiontoastronomicalspectroscopy/ImmoAppenzeller. pages cm.–(Cambridgeobservinghandbooksforresearchastronomers;9) Includesbibliographicalreferencesandindex. ISBN978-1-107-01579-1(hardback)–ISBN978-1-107-60179-6(paperback) 1.Astronomicalspectroscopy. I.Title. QB465.A67 2013 522(cid:2).67–dc23 2012019846 ISBN978-1-107-01579-1Hardback ISBN978-1-107-60179-6Paperback CambridgeUniversityPresshasnoresponsibilityforthepersistenceoraccuracyofURLs forexternalorthird-partyInternetWebsitesreferredtointhispublicationanddoesnot guaranteethatanycontentonsuchWebsitesis,orwillremain,accurateorappropriate. Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:52:16, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503 Contents Preface pagexi 1 HistoricalRemarks 1 1.1 EarlyPioneers 1 1.2 ThePhotographicEra 6 1.3 TheImpactofLinearDetectors 10 1.4 ExtendingtheWavelengthRange 19 2 SpectroscopyinPresent-DayAstronomy 26 2.1 SpectralClassification 26 2.2 RadialVelocities 30 2.3 GravitationalandCosmologicalRedshifts 32 2.4 AstrophysicalApplications 35 2.5 MagneticFields 43 2.6 TheImportanceofSpectralResolution 46 3 BasicPhysicsofSpectralMeasurements 50 3.1 ElectromagneticRadiation 50 3.2 MeasuringFrequencies 54 3.3 MeasuringWavelengths 55 3.4 AccuracyLimits 76 4 Optical-RangeGratingandPrismSpectrometers 81 4.1 CommerciallyAvailableSpectrometers 81 4.2 BasicComponentsofAstronomicalSpectrometers 82 4.3 SlitlessSpectroscopy 85 4.4 Single-ObjectSlitSpectrometers 87 4.5 Fiber-CoupledInstruments 107 vii Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:53:11, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503 viii Contents 4.6 MultiobjectSpectrometers 110 4.7 IntegralFieldSpectroscopy 115 4.8 ColdIRSpectrometers 119 5 OtherTechniquesfortheOpticalSpectralRange 127 5.1 Fabry-PerotTechniques 127 5.2 FourierTransformSpectrometers 134 5.3 DirectDetectionofVisualPhotonEnergies 138 6 PreparingandReducingOpticalObservations 145 6.1 PlanningandPreparingObservingRuns 145 6.2 TheExecutionPhase 154 6.3 CalibrationProcedures 156 6.4 ReductionofRawSpectra 159 6.5 ArchivingSpectralData 176 7 UV,X-Ray,andGammaSpectroscopy 179 7.1 UVandX-RayOptics 180 7.2 UVSpectrometers 187 7.3 Photon-EnergySensitiveX-RayDetectors 189 7.4 X-RayGratingSpectrometers 191 7.5 GammaSpectroscopy 194 8 SpectroscopyatRadioWavelengths 200 8.1 DetectionofRadioWavesfromSpace 201 8.2 FilterBanks 203 8.3 FastFourier-TransformSpectrometers 204 8.4 AutocorrelationTechniques 206 8.5 Cross-CorrelationSpectroscopywithArrays 209 8.6 Acousto-OpticalInstruments 210 8.7 Chirp-TransformSpectrometers 212 9 SpecialTechniquesoftheFIRand SubmillimeterRange 214 9.1 SpectroscopywithBolometers 215 9.2 HeterodyneSpectroscopyatFIRandSubmillimeter Wavelengths 221 10 NewDevelopmentsandFutureProspects 224 10.1 ScientificDrivers 224 10.2 NewFacilities 225 Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:53:11, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503 Contents ix 10.3 NewTechnologies 231 10.4 OrganizationalChallenges 236 Appendix:ListofAcronyms 239 References 245 Index 251 Downloaded from https://www.cambridge.org/core. Nottingham Trent University, on 22 Aug 2019 at 20:53:11, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/CBO9781139059503