GAMMA-RAY BURST HOST GALAXIES AT HIGH RESOLUTION CHRISTINA CARINA THÖNE Dissertation Submitted for the Degree PHILOSOPHIÆ DOCTOR Dark Cosmology Centre Niels Bohr Institut Det Naturvidenskabelige Fakultet Københavns Universitet Submission: July 4th, 2008 Defence: October 3rd, 2008 Supervisor: Assoc. Prof. Johan P. U. Fynbo Opponents: Prof. Max Pettini Dr. Chryssa Kouveliotou Cover art: Going observing brings you not only scientific images, sometimes, there is also time to do pretty pictures, either with the telescope itself or with your own camera. This cover joins both. The panorama at the bottom was taken in a very cold full moon night in August 2008 on La Silla after a thunderstorm and fresh snow in the Cordillera Central. The pictures were taken in raw format and dark- and bias-subtracted before joining them to a panorama. Thanks to Antonio for making this nice panorama from the raw files taken with my small, but apparently not so crappy Olympus. The telescope at the right side of the back cover shows UT1 of the VLT telescopes, taken a few days before under nearly full moon, this time with Antonios camera and a tripod. The dome to the left belongs to one of the two Keck telescopes on Mauna Kea. The main image of the cover is a mosaic of the nebula around η Carinae, a massive luminous blue variable but likely never becoming a GRB, created by its violent outbursts and mass losses over the last 100 years with the star itself hiding behind the dark dust clouds. The mosaic consists of 8 panels taken in V, R and I filters with the Danish 1.54m telescope in February 2006. Thanks to Robert Gendler for processing and merging the images. The little "cosmic explosion" in the upper left of the back cover is a picture of our own sun taken during the solar eclipse 2006 which I watched from a hotel near Antalya/Turkey during a GRB workshop. It marks the end of the eclipse when the sun is shining through the valleys at the edge of the moon creating the diamond ring effect. It is also a symbol for the background picture I had on my mobile phone used for GRB triggering over the last years which showed a picture of the moon with some artistic rays around but which I could not get in high resolution. The cover was put together in Photoshop, thanks to Ana Lucía for helping with various problems in Photoshop. The titlepage of Part I of the thesis is a color composite of the starburst galaxy M82 taken with ALFOSC at the NOT in B, V and Hα filters and symbolizes the absorption lines likely caused by starburst winds from GRB hosts that we detected in the spectra of GRB 030329 and GRB 060206. Thanks to Johan for making the color image. The title of Part II shows a part of the η Carinae mosaic and a color composite of a galaxy whose name I forgot. It was taken at the Brorfelde observatory west of Copenhagen when Chloé and I were training for going observing the first time back in October 2005. The two pictures are a symbol for the resolved host galaxies of GRB 060505 and SN 2008D and for the fact that we were interested in the progenitors of GRBs/SNe in that part of the thesis. CONTENTS Contents v Acronyms xi List of Figures xiii List of Tables xv Acknowledgments xvii Abstract xxi Sammenfatning xxiii Zusammenfassung xxvi 1 Introduction 5 1.1 A serendipitous discovery . 5 1.1.1 Once upon a time... 5 1.1.2 Better localization - the IPN . 5 1.1.3 CGRO . 6 1.1.4 The first afterglows - Beppo SAX and HETE . 7 1.1.5 The Swift era.................................... 8 1.1.6 GLAST and the future . 9 1.2 The most powerfull explosions in the Universe . 11 1.2.1 Prompt emission - the fireball model . 11 1.2.2 Progenitors of GRBs . 15 1.2.3 Cosmology with GRBs? . 18 1.3 The galaxy . 18 1.3.1 Long GRB hosts . 19 1.3.2 Short GRB hosts . 20 1.4 It’s all about being fast or when the mobile rings twice . 21 1.4.1 The GCN Network . 21 1.4.2 ToO observations . 22 1.4.3 Examples of ToO observations and results . 23 v IABSORPTION LINE SPECTROSCOPY OF GRB AFTERGLOWS 29 2 What do we learn from distant GRB hosts? 31 2.1 The high redshift universe . 31 2.1.1 Indirect observations - Quasar absorption line systems . 31 2.1.2 Direct imaging . 33 2.2 Absorption line profiles and column density determinations . 34 2.2.1 Doppler, Lorentz- and Voigt profiles . 34 2.2.2 The Curve of Growth method . 36 2.2.3 Apparent optical depth . 37 2.2.4 Voigt profile fitting . 37 2.3 The metallicity problem . 38 2.3.1 QSO and GRB metallicities . 38 2.3.2 Relative abundances and dust depletion . 40 2.4 Distances . 41 2.4.1 Finestructure lines . 42 2.4.2 Neutral species . 43 2.4.3 Indication for material from the circumburst medium? - NV in GRB sight- lines . 44 2.5 The dynamical universe . 44 2.5.1 Winds from the progenitor star? . 44 2.5.2 Rotating disks and Superwinds . 45 3 Photometry and Spectroscopy of GRB 060526 49 3.1 Introduction . 49 3.2 Observations . 50 3.2.1 Photometry . 50 3.2.2 Spectroscopy . 51 3.2.3 The multi-color light curve . 51 3.2.4 Analysis of the light curve variability . 53 3.2.5 Modelling the light curve numerically with energy injections . 55 3.2.6 The spectral energy distribution and host extinction . 56 3.2.7 Host search . 57 3.3 Spectroscopy results . 59 3.3.1 Line identification . 59 3.3.2 Column densities from curve of growth analysis . 59 3.3.3 Metallicity and relative abundances . 62 3.4 Discussion and conclusions . 63 3.4.1 A highly variable light curve . 63 3.4.2 A moderate metallicity environment . 64 4 ISM studies of GRB 030329 with high resolution spectroscopy 69 4.1 Introduction . 69 4.2 Data sample . 70 4.3 Line analysis . 71 4.3.1 Emission lines . 71 4.3.2 Absorption lines . 73 4.4 Results . 75 4.4.1 Redshift . 75 4.4.2 Broadening of the emission lines . 75 4.4.3 Galactic and host extinction . 76 4.4.4 SFR . 76 4.4.5 Metallicity of the host . 77 4.5 Absorption line kinematics . 77 4.5.1 Fitting of the absorption systems . 77 4.5.2 Interpretation of the Mg I & II velocity structure . 79 4.6 Conclusion . 81 5 The host of GRB 060206: kinematics of a distant galaxy 83 5.1 Introduction . 83 5.2 Observations . 84 5.2.1 Spectroscopy . 84 5.2.2 Imaging . 84 5.3 Extinction along the line-of-sight . 85 5.4 Absorption line analysis . 85 5.5 Velocity components in the host galaxy . 86 5.5.1 Fine structure levels . 86 5.5.2 N V absorption lines . 91 5.5.3 The nature of the absorption systems . 92 5.5.4 Comparison with QSO-DLAs . 93 5.6 The host in emission . 94 5.7 An intervening system at z = 1.48 ........................... 95 5.7.1 Properties of the intervening absorber . 95 5.7.2 Variability of the intervening system? . 96 5.7.3 Identifying the absorber in emission . 96 5.8 Conclusions . 98 II RESOLVED HOST GALAXIES AND THE SN-GRB MYSTERY 101 6 GRBs with Supernovae, Supernovae without GRBs and GRBs without supernova 103 6.1 The SN-GRB connection . 103 6.1.1 The common picture between 1998 and 2006.