Chasing the Brightest Cosmic Explosions with ROTSE-III by Fang Yuan A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Physics) in The University of Michigan 2010 Doctoral Committee: Professor Carl W. Akerlof, Chair Professor Fred Adams Professor Timothy A. McKay Professor Bing Zhou Assistant Professor Jon M. Miller c Fang Yuan 2010 All Rights Reserved To my family ii ACKNOWLEDGEMENTS First of all, I can never express my gratitude enough to Carl Akerlof, who has taught me so much in and beyond the field of physics. Carl's wonderful mentoring has made my PhD study such an enjoyable experience. As a proud member of the ROTSE group, I am grateful to all these brilliant people, Eli Rykoff, Tim McKay, Heather Flewelling, Sarah Yost, Wiphu Rujopakarn, Don Smith and many more, that have worked with ROTSE and have made it such a superb instrument and fun project to work with. It has been a great pleasure to work with the friendly and capable observatory staffs, in particular David Doss, Toni Hanke, Tuncay Ozı¨ ¸sık and Andre Phillips. A critical part of this thesis has been made possible through collaboration with an excellent group of researchers in the University of Texas. It all began with the ingenious idea of Robert Quimby, from whom I have gained invaluable technical and mental support when starting RSVP. I am indebted to Craig Wheeler for all the wise insights and generous encouragement. I also thank Jozsef Vinko for all the kindly help. The success of RSVP has relied on the efforts from many undergraduates, including Jamie Aretakis, Dan Chamarro, Matt Sisson and Amelia Uecker. I would like to acknowledge Weikang Zheng and Shashi Pandy for taking graceful care of ROTSE when I am busy finishing up this thesis. iii I wish to thank my parents for their unconditional love and support that make me feel safe and connected whatever I do wherever I am. Finally, thank you Qiaoqiao for making me a very happy person. Part of chapter 3 of this thesis is accepted for publication in the Astrophysical Journal. Part of chapter 4 is based on Yuan & Akerlof (2008). Part of chapter 5 has been submitted to the Astrophysical Journal. iv TABLE OF CONTENTS DEDICATION : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : ii ACKNOWLEDGEMENTS : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : iii LIST OF FIGURES : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : viii LIST OF TABLES : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : x LIST OF ABBREVIATIONS : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : xi ABSTRACT : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : xiii CHAPTER I. Introduction . 1 II. GRB and the Fireball Model . 4 2.1 Introduction . 4 2.2 Pre-Swift Phenomenology . 6 2.2.1 Prompt Burst Emission . 6 2.2.2 Afterglow . 7 2.2.3 SNe Association . 7 2.3 The Fireball Model . 8 2.3.1 Relativistic Outflow . 8 2.3.2 Emission Mechanisms . 8 2.3.3 Jets . 9 2.3.4 Very High Energy Emission . 10 2.4 The Swift-era . 12 2.4.1 Bursts Statistics . 12 2.4.2 Canonical X-ray Lightcurves . 13 2.4.3 Very Early Optical Observations . 13 2.4.4 Missing Jet Breaks? . 15 2.4.5 High Redshift Bursts . 17 2.4.6 Host . 18 2.4.7 Progenitor . 18 III. Observations of GRBs by ROTSE-III . 20 3.1 Introduction . 20 3.2 GRB 081008: from Burst to Afterglow and the Transition Phase in Between 21 v 3.2.1 Observations and Data Reduction . 22 3.2.2 Spectral and Temporal analysis . 28 3.2.3 Discussion . 37 3.2.4 Conclusions . 45 3.3 Other GRBs Observed by ROTSE-III . 47 3.3.1 Data Reduction . 47 3.3.2 GRB 071025 . 49 3.3.3 GRB/XRF 080330 . 52 3.3.4 GRB 080413A . 54 3.3.5 GRB 080603B . 56 3.3.6 GRB 080607 . 58 3.3.7 GRB 080703 . 61 3.3.8 GRB 080804 . 62 3.3.9 GRB 080928 . 64 3.3.10 GRB 081029 . 66 3.3.11 GRB 081121 . 68 3.4 Early Behavior of GRBs . 70 3.4.1 High Energy Observations . 70 3.4.2 Optical and X-ray Spectra . 70 3.4.3 Optical and Hard X-ray (BAT) Spectra . 71 3.4.4 Conclusion . 73 IV. ROTSE Supernova Verification Project . 74 4.1 Introduction . 74 4.2 Science Goals . 76 4.2.1 Ultra-luminous SNe . 76 4.2.2 SNe Ia . 81 4.3 Image Subtraction by Cross-Convolution . 86 4.3.1 Mathematical Method . 87 4.3.2 Computational Methods . 90 4.3.3 Operational Experience . 96 4.4 Transient Search Pipeline . 97 4.4.1 Target Fields Selection . 97 4.4.2 Construction of References and Bad Pixel Maps . 104 4.4.3 Data Flow and Automated Candidate Filtering . 106 4.4.4 Web Scan and Follow-up Schedules . 107 V. RSVP supernovae . 111 5.1 Introduction . 111 5.2 ROTSE-III Observations of the SNe . 112 5.2.1 Data Reduction . 112 5.2.2 Discoveries and Photometry . 112 5.2.3 SN 2007gr . 112 5.2.4 SN 2007if . 129 5.2.5 SN 2007is . 130 5.2.6 SN 2007iu . 130 5.2.7 SN 2007kh . 130 5.2.8 SN 2007nq . 131 5.2.9 SN 2007ob . 131 5.2.10 SN 2007op . 132 5.2.11 SN 2007qc . 132 5.2.12 SN 2007qe . 132 vi 5.2.13 SN 2007rx . 133 5.2.14 SN 2007sp . 133 5.2.15 SN 2007su . 133 5.2.16 SN 2007sw . 134 5.2.17 SN 2008E . 134 5.2.18 SN 2008ab . 134 5.2.19 SN 2008ac . 135 5.2.20 SN 2008ad . 135 5.2.21 SN 2008am . 135 5.2.22 SN 2008ar . 137 5.2.23 SN 2008bg . 137 5.2.24 SN 2008bj . 137 5.2.25 SN 2008by . 138 5.2.26 SN 2008bz . 138 5.2.27 SN 2008cw . 138 5.2.28 SN 2008dx . 139 5.2.29 ROTSE3 J125642.7+273041 . ..