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Uva-DARE (Digital Academic Repository) UvA-DARE (Digital Academic Repository) Gamma-Ray Burst afterglows Galama, T.J. Publication date 1999 Link to publication Citation for published version (APA): Galama, T. J. (1999). Gamma-Ray Burst afterglows. General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl) Download date:30 Sep 2021 Contents s 11 Introduction 7 1.11 What are 7-ray bursts? 7 1.1.11 Vela satellites 7 1.1.22 Light curves and spectra of GRBs 8 1.1.33 Distribution on the sky and in space 9 1.1.44 The 'great' debate 12 1.1.55 Counterparts 14 1.22 Rel ativistic blast wave models 15 1.2.11 The compactness problem, relativistic motion and baryon loading ... 15 1.2.22 Blast wave dynamics 17 1.2.33 Low-energy emission at late times: afterglow 19 1.33 Afterglow 20 1.3.11 The first identifications 20 1.3.22 Confirmation of the relativistic blast-wave model 20 1.44 Current status and open questions 21 1.4.11 GRB progenitors and the cause of the explosion 21 1.4.22 The relationship between GRBs and the star-formation rate 22 1.4.33 GRBs as potential probes of the high-redshift Universe 22 1.4.44 Not all GRBs have afterglows 22 1.4.55 Different classes of GRBs; supernova-GRBs 29 1.4.66 The early afterglow 30 1.4.77 Strongly anisotropic outflow (beaming) 30 1.55 Overview of this thesis 30 Referencess 33 22 Two variable radio sources near the position of GRB 940301 39 2.11 Introduction 39 2.22 GRB 940301 40 2.33 Observations and data reduction 41 2.44 A search for variability 42 2.55 Two variable radio sources 43 2.66 Discussion 46 2.77 Conclusions 48 Referencess 48 1 1 Contents Contents 33 Unusual increase in the 325 MHz flux density of PSR B0655+64 51 3.11 Introduction 51 3.22 PSR B0655+64 52 3.33 Observations and data reduction 52 3.44 Results 53 3.4.11 Elongated structure 53 3.4.22 Light curves 54 3.4.33 Decorrelation bandwidth 56 3.4.44 DISS behavior 57 3.4.55 Average flux densities and RISS behavior 58 3.55 Discussion 59 3.5.11 Ordinary scintillation 59 3.5.22 Caustics 61 3.5.33 Intrinsic variation 63 3.5.44 Other events 63 3.66 Conclusions 63 Referencess 64 44 Radio and optical follow-up observations and improved IPN position of GRB9701111 65 4.11 Introduction 65 4.22 GRB 970111 gamma-ray observations 66 4.2.11 BATSE observations 66 4.2.22 IPN-BeppoSax WFC combined error box 67 4.33 Radio and optical observations 67 4.3.11 Radio observations 67 4.3.22 Optical observations 69 4.44 Discussion 70 Referencess 73 55 Transient optical emission from the error box of the 7-ray burst of 28 February 19977 75 5.11 GRB 970228 75 5.22 Optical observations 77 5.33 Variability background 78 5.44 Multiwavelength observations 80 5.55 Positional coincidence with a galaxy 80 5.66 Conclusions 81 Referencess 82 66 The decay of optical emission from the 7-ray burst GRB 970228 85 6.11 Introduction 85 6.22 The R-band light curve 86 6.33 Discussion 89 Referencess 90 2 2 Contents Contents 77 Optical follow-up of GRB 970508 91 7.11 Introduction 91 7.22 Optical photometry 92 7.33 The Rc-band differential optical light curve 92 7.44 Broad-band optical flux distribution 94 7.55 Discussion 95 Referencess 97 88 The 1.4 GHz light curve of GRB 970508 99 8.11 Introduction 99 8.22 Radio observations 100 8.2.11 The light curve 100 8.33 Discussion 103 Referencess 104 99 The radio to X-ray spectrum of GRB 970508 on May 21.0 UT 107 9.11 Introduction 107 9.22 The X-ray to radio spectrum on May 21.OUT 108 9.33 Discussion 109 9.3.11 The radio to X-ray spectrum 109 9.3.22 Evidence for a second spectral break 109 9.3.33 Rapid electron cooling 110 9.3.44 Constraints on the break frequencies uQ and um for May 21.0 UT . ... 110 9.3.55 The near-infrared range 112 9.3.66 Adiabatic dynamical evolution of the blast wave and the value of to 112 9.44 Conclusion 113 Referencess 113 100 Physical parameters of GRB 970508 and GRB 971214 from their afterglow syn- chrotronn emission 115 10.11 Introduction 115 10.22 Radiation from an adiabatic blast wave 116 10.2.11 Blast wave dynamics 116 10.2.22 Synchrotron radiation 118 10.33 Observed and inferred parameters of GRB 970508 121 10.44 Properties of GRB 971214 124 10.4.11 The optical break as vm 125 10.4.22 The optical break as uc 125 10.55 Conclusion 128 Referencess 129 111 A search for optical afterglow from GRB 970828 131 11.11 Introduction 131 11.22 Observations and data analysis 132 11.33 Discussion 133 11.3.11 Comparison with optical afterglows of GRB 970228 and GRB 970508 . 133 11.3.22 Comparison with relativistic blast wave models 134 3 3 Contents Contents 11.3.33 Absorption in redshifted material 135 Referencess 137 122 The rapid decay of the optical emission from GRB 980326 and its possible implica- tionss 139 12.11 Introduction 139 12.22 The optical counterpart 140 12.33 Constraints on the electron distribution 142 12.44 The maximum value of p 142 12.55 Explanations for non-detections: rapid decays and galactic halos 144 12.66 Conclusions 145 Referencess 146 133 An unusual supernova in the error box of the 7-ray burst of 25 April 1998 149 13.11 GRB 980425 149 13.22 Optical observations 150 13.33 The connection between SN1998bw and GRB 980425 150 13.44 X-ray sources 152 13.55 Discussion 155 Referencess 158 144 The X-ray, optical and infrared counterpart to GRB 980703 159 14.11 Introduction 159 14.22 X-ray observations 160 14.33 Optical and infrared observations 162 14.44 Discussion 165 Referencess 168 155 The effect of magnetic fields on 7-ray bursts inferred from multi-wavelength ob- servationss of the burst of 23 January 1999 171 15.11 Introduction 171 15.22 Observations 172 15.2.11 Prompt 7-ray emission 172 15.2.22 Multi-wavelength afterglow emission 173 15.33 Discussion 178 Referencess 182 166 Evidence for a supernova in reanalyzed optical and near-infrared images of GRBB 970228 185 16.11 Introduction 185 16.22 Reanalysis of previous observations 186 16.2.11 Calibration 186 16.2.22 The details of each observation 188 16.2.33 The host galaxy 191 16.33 The light curves 192 16.44 Optical/near-infrared to X-ray spectra 193 16.55 Discussion 194 4 4 Contents Contents Referencess 199 177 Nagloeien van gamma-uitbarstingen 201 17.11 De eerste jaren 202 17.22 De lancering van BATSE 202 17.33 De BeppoSAX satelliet 203 17.44 Nagloeien van gamma-uitbarstingen: GRB 970228 204 17.55 Het gehele electromagnetisch spectrum 205 17.66 Vuurbal 205 17.77 GRB 980425: supernova gamma-uitbarsting 206 17.88 GRB 990123: grootste explosie ooit waargenomen 207 17.8.11 Heldere lichtflits 207 Listt of Publications 211 Dankwoordd 221 5 5 Contents Contents 6 6 .
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