Very high energy gamma-ray astronomy

238 Pages·2003·4.184 MB·English

by  T.C. Weekes

Very High Energy Gamma-Ray Astronomy
Series in Astronomy and Astrophysics
SeriesEditors: MBirkinshaw,UniversityofBristol,UK
MElvis,Harvard–SmithsonianCenterforAstrophysics,USA
JSilk,UniversityofOxford,UK
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Series in Astronomy and Astrophysics
Very High Energy Gamma-Ray
Astronomy
Trevor Weekes
Whipple Observatory, Harvard–Smithsonian Center for
Astrophysics, USA
Institute of Physics Publishing
Bristol and Philadelphia
(cid:1)c IOPPublishingLtd2003
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PatentsAct1998tobeidentifiedastheauthorofthiswork.
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SeriesEditors: MBirkinshaw,UniversityofBristol,UK
MElvis,Harvard–SmithsonianCenterforAstrophysics,USA
JSilk,UniversityofOxford,UK
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To Ann who gave me moral support through four
decades of gamma-ray astronomy

Contents
Foreword xiii
1 Foundationsofgamma-rayastronomy 1
1.1 Astronomicalexploration 1
1.2 Therelativisticuniverse 2
1.3 Definitions 4
1.4 Theheroiceraofgamma-rayastronomy 5
1.4.1 Theearlypromise 5
1.4.2 Peculiaritiesofgamma-raytelescopes 6
1.4.3 VHEgamma-raytelescopesontheground 7
Historicalnote:seminalpaper 10
1.4.4 HEgamma-raytelescopesinspace 11
2 Veryhighenergygamma-raydetectors 13
2.1 Theatmosphericwindows 13
2.2 Electromagneticcascadeinatmosphere 14
2.3 Thevisibleelectromagneticcascade 14
2.4 AtmosphericCherenkovtechnique 18
2.4.1 Generalproperties 18
2.4.2 Featuresofthetechnique 21
2.5 Thebackgroundofcosmicradiation 25
2.5.1 Chargedcosmicrays 25
2.5.2 Fluxsensitivity 27
2.6 AtmosphericCherenkovimagingdetectors 28
2.6.1 Principle 28
2.6.2 Angularresolution 30
2.6.3 Energyresolution 30
2.6.4 Existingimagingtelescopes 30
2.6.5 Arrays 34
2.7 Otherground-baseddetectors 38
2.7.1 Particleairshowerarrays 38
2.7.2 SolarpowerstationsasACTs 38
Historicalnote:Cherenkovimages 40
viii Contents
3 Highenergygamma-raytelescopesinspace 42
3.1 Introduction 42
3.2 Pairproductiontelescopes:highenergy 42
3.3 Comptontelescopes 46
3.4 Futurespacetelescopes 48
3.4.1 INTEGRAL 48
3.4.2 Swift 49
3.4.3 Lightimagingdetectorforgamma-rayastronomy(AGILE) 49
3.4.4 AlphaMagneticSpectrometer(AMS) 50
3.4.5 TheGamma-rayLarge-AreaSpaceTelescope(GLAST) 50
Historicalnote:CGROrescue 54
4 Galacticplane 55
4.1 Studyofthegalacticplane 55
4.2 Gamma-rayobservations 58
4.2.1 HEobservations 58
4.2.2 VHEobservations 58
4.3 Interpretation 60
4.4 Energyspectrum 62
Historicalnote 65
5 Supernovaeandsupernovaremnants 67
5.1 Supernovaexplosions 67
5.2 Energyconsiderations 68
5.3 Acceleration 70
5.4 Detectionatoutburst 71
5.5 Supernovaremnantclassification 72
5.6 SNRsascosmicraysources 74
Historicalnote:SN1987a 75
6 Gamma-rayobservationsoftheCrabNebula 77
6.1 Significance 77
6.2 Opticalandx-rayobservations 78
6.3 Gamma-rayhistory 79
6.3.1 HEobservations 79
6.3.2 VHEobservations 82
6.4 Gammasource 83
6.4.1 TheCrabresolved 83
6.4.2 Thestandardcandle 85
6.4.3 Interpretation 88
Historicalbox:Crabpictograph 90
Contents ix
7 Gamma-rayobservationsofsupernovaremnants 92
7.1 Introduction 92
7.2 Plerions 92
7.2.1 SNR/PSR1706-44 92
7.2.2 Vela 93
7.3 Shell-typeSNRs 93
7.3.1 SN1006 93
7.3.2 RXJ1713.7-3946 95
7.3.3 CassiopeiaA 95
7.3.4 Otherpossibledetections 97
Historicalnote:supernovaof1006 99
8 Gamma-raypulsarsandbinaries 102
8.1 Generalpropertiesofpulsars 102
8.2 Gamma-rayobservations 104
8.2.1 Generalcharacteristics 104
8.2.2 Spectralenergydistribution 105
8.2.3 Lightcurves 106
8.3 Models 109
8.3.1 Polarcapmodels 109
8.3.2 Outergapmodels 109
8.4 Outlook 111
8.5 Binaries 111
Historicalnote:CygnusX-3 113
9 Unidentifiedsources 116
9.1 HEobservations 116
9.2 Populationstudies 117
9.3 Individualidentifications 120
9.3.1 CG135+01 120
9.3.2 3EGJ0634+0521:binarypulsar? 121
9.3.3 3EGJ1835+5918:Geminga-likepulsar? 121
9.3.4 Galacticcenter 121
9.4 Microquasars 122
9.5 VHEobservations 123
Historicalnote:Geminga 124
10 Extragalacticsources 126
10.1 Introduction 126
10.2 Galaxies:classification 126
10.3 Normalgalaxies 127
10.4 Starburstgalaxies 128
10.5 Activegalaxies 128
10.5.1 Radiogalaxies 129
10.5.2 Activegalacticnuclei 130