UNIVERSITY COLLEGE LONDON Faculty of Mathematics and Physical Sciences Department of Physics & Astronomy A MID-INFRARED STUDY OF DUST EMISSION FROM CORE-COLLAPSE SUPERNOVAE Thesis submitted for the Degree of Doctor of Philosophy of the University of London by Joanna Natalina Fabbri Supervisors: Examiners: Prof. Michael J. Barlow Prof. Stephen Eales Prof. Jonathan M. C. Rawlings Dr. Serena Viti May 13, 2011 To my family and friends, without whom this journey would not have been possible. Declaration I, Joanna Natalina Fabbri, confirm that the work presented in this thesis is my own. Where information has been derived from other sources, I confirm that this has been indicated in the thesis. “Share your knowledge. It is a way to achieve immortality.” – The Dalai Lama “I don’t want to achieve immortality through my work... ...I want to achieve it through not dying.” – Woody Allen Abstract The aim of this thesis has been to help elucidate the potential contribution of core-collapse supernovae (SNe) to the dust-enrichment of galaxies. It has long been hypothesised that SNe are a major source of dust in the Universe, an assumption that has gained support with the discovery that many of the earliest-formed galaxies are extremely dusty and infrared- luminous, as evidenced by the efficient detection of their redshifted infrared emission at submillimeter wavelengths. Massive-star, core-collapse SNe, of Types II, Ib and Ic, arising from the starbursts that power these galaxies, are plausible sources of this dust. However, very little is currently known about how much dust forms in SN outflows. To this end, sensitive mid-infrared surveys for thermal dust emission from recent core-collapse SNe have been conducted with the Spitzer Space Telescope and mid-infrared detectors on the Gemini telescopes, in order to seek evidence for dust formation and evolution in SN ejecta. Of the 30 SNe observed, only five were robustly detected. These were comprised of four Type II-P SNe: SN 2002hh, SN 2003gd, SN 2004dj and SN 2004et; and the Type IIn SN 1999bw. The mid-infrared data of SN 2004et were incorporated with optical and near-infrared data to provide a comprehensive study of this SN from days 64 to 2151 post 3 explosion. Radiative transfer models predict up to 1.5 10− M of dust had condensed in × the ejecta of SN 2004et by day 690. Upper limits to mid-infrared fluxes are presented for 25 supernova and used to obtain upper limits to their dust masses in the mid-infrared. The results from this research add to the weight of observational evidence which suggests the ejecta of core-collapse SNe do not produce sufficient dust, at least during the first 3 or 4 years after outburst, to explain the masses of dust derived for some galaxies in the early Universe. 4 Acknowledgements The first thank you goes to my PhD supervisor Mike Barlow whose unwavering help and support have been above and beyond the call of duty. Your infallible wisdom and famous red pen have helped me to achieve this PhD, and I am immensely grateful for the opportunities you have provided me with, and for your encouragement and reassurance right to the end. To my parents and to my sister, thank you for your unconditional love, patience and support. You have no idea. I literally couldn’t have done it without you. Mum, your home-cooked meals made the numerous occasions of three meals a day at my desk bearable and delicious, as did your pizzas, Dad! Thank you for providing the roof over my head which allowed me the luxury of completing this PhD, and for not asking too many questions (even when it was driving you crazy not to). Vicky, thank you for your generosity, for understanding me, for running with me and for keeping me sane. To my boyfriend, Fab. My best friend. Whilst each has played their own important part in helping me to achieve this PhD, I seriously doubt I could have seen it through to the end without you. You have been my constant and my rock, through both the darkest and the happiest moments. To have shared this experience with you was alone worth doing the PhD for. Thank you is not enough... but one day we will both go to Hawaii! My time at UCL has been long and I have many colleagues/friends/office mates, past and present, to thank for helping make the tough times easier and the whole experience much more pleasurable. Not all are mentioned here, but you know who you are. In no particular order, special thanks to Barbara Ercolano, Sam Searle, Simon Hodges, Will Nicholson, Iris Yiu, Dugan Witherick, Fiona Groenhout (honorary astronomer), John Deacon, Adam Burnley, Matt North, Nutan Rajguru, Bethan James and Jamie Noss. 5 6 All those thesis-encouraging and (equally important) thesis-distracting chats, the late- night Housman Room sessions, the good food shared, and the runs around Regent’s Park - we have had truly great times and I have so many happy memories. Roger Wesson gets a special thank you for his time answering all those Questions I Couldn’t Ask Mike, and for the split eye when playing squash! It’s been a pleasure. I would also like to thank all the SEEDS members, particularly Ben Sugerman for mentoring me in the practicalities of research and for the occasional ‘tough love’ email. Thank you for your extensive time and friendship. To all my friends and family whom I love dearly, and with whom spending time with has often been sacrificed in the pursuit of this PhD, thank you for your patience, love and support. To name a few names: Gemma, Tara, Sarah, Sara, Jessica, Eve, Emma, Catherine, Amira, the Sidoli’s, Gerard, and my Nan. But there are more of you and you are all just as important. A final thank you to George, Arnaud and Isaac for their happiness, friendship and JD and cokes, during those numerous visits to the Housman Room. I must also mention the many staff of ULU Gordons cafe for their supply of caffeine and pain au chocolate - a small slice of romance to start (many of) my thesis-writing days! Thank you. Grazie. Arigato gozaimashita. Gamsa hamnida. Mahalo. Contents Abstract 4 Acknowledgements 5 Table of Contents 7 List of Figures 13 List of Tables 16 1 Introduction 18 1.1 The role of interstellar dust in astrophysics . 18 1.2 The life cycle of interstellar dust . 19 1.3 Dust production by supernovae . 20 1.3.1 Supernova types . 20 1.3.2 Evidence for dust formation in SNe . 22 Theoretical studies . 22 Dust in high-redshift galaxies . 23 Meteorite inclusions . 23 1.3.3 Early infrared observations . 25 1.3.4 SN 1987A . 25 1.3.5 Dust in other massive-star supernovae . 29 SN 1990I . 29 SN 1998S . 29 SN 1999em . 30 7 Contents 8 1.3.6 Supernova remnants . 31 1.3.7 The three signatures of ejecta-condensed dust . 33 1.4 Thesis outline and the SEEDS collaboration . 34 2 Gemini Observations of Supernovae 36 2.1 Introduction . 36 2.2 The sample definition and selection . 36 2.3 Ground-based mid-IR astronomy and the Gemini Observatory . 40 2.3.1 Atmospheric transmission . 41 2.3.2 Chopping and nodding and observing overheads . 43 2.3.3 The Gemini instruments . 45 OSCIR - Instrument description . 45 T-ReCS - Instrument description . 45 Michelle - Instrument description . 47 2.4 The Gemini observations . 48 2.4.1 Gemini-North/OSCIR program GN-2001A-C-10, May 2001 . 48 2.4.2 Gemini-South/T-ReCS program GS-2004A-Q-1, Mar – Dec 2004 . 50 2.4.3 Gemini-North/Michelle Director’s Discretionary program GN-2004B-DD-4, Sep – Oct 2004 . 53 2.4.4 Gemini-North/Michelle program, Feb 2005 – Jul 2008 . 53 GN-2005A-Q-20 observations, Feb – Jul 2005 . 55 GN-2005B-Q-2 observations, Aug 2005 . 56 GN-2006A-Q-1 observations, Apr – Jun 2006 . 56 GN-2006B-Q-1 observations, Sep/Oct 2006 and Mar 2007 . 56 GN-2007A-Q-5 observations, Mar – Apr 2007 . 57 GN-2007B-Q-4 and GN-2008B-Q-44 observations, Jun – Jul 2008 . 57 2.5 Gemini mid-IR data reduction . 61 2.5.1 OSCIR data reduction . 61 2.5.2 T-ReCS and Michelle data reduction . 61 2.5.3 Final image manipulation: cleaning and combining . 63 2.5.4 Flux calibration . 64 2.6 Flux density measurements: detections and upper limits . 66 2.6.1 Aperture photometry with IRAF phot ................ 67 Contents 9 2.6.2 PSF-fitted photometry with IRAF daophot .............. 69 2.6.3 Non-detections – upper limits to flux densities . 70 2.6.4 Error analysis . 71 2.7 Discussion of results . 72 2.8 Summary . 77 3 Spitzer Observations of Supernovae 79 3.1 Introduction . 79 3.2 Space-based mid-IR astronomy & the Spitzer Space Telescope ......... 79 3.2.1 The Spitzer instruments . 80 The Infrared Array Camera - IRAC . 82 The Multiband Imaging Photometer for Spitzer - MIPS . 83 The Infrared Spectrograph - IRS . 86 3.2.2 Observing with the Spitzer Space Telescope ............... 87 3.3 The Spitzer observations . 89 3.3.1 The SINGS Legacy program: 00159 . 89 The SINGS observations . 89 3.3.2 Cycle 1 General Observations (GO) program: 03333 . 90 3.3.3 Cycle 2 GO program: 20320 . 93 3.3.4 Cycle 3 GO program: 30494 . 97 3.3.5 Cycle 4 GO program: 40010 . 99 3.4 Spitzer data reduction . 101 3.4.1 Data retrieval . 101 3.4.2 The SSC data reduction pipelines and flux calibration .