Clemson University TigerPrints All Theses Theses 5-2017 High-redshift lB azars through NuSTAR Eyes Lea Marcotulli Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_theses Recommended Citation Marcotulli, Lea, "High-redshift lB azars through NuSTAR Eyes" (2017). All Theses. 2653. https://tigerprints.clemson.edu/all_theses/2653 This Thesis is brought to you for free and open access by the Theses at TigerPrints. It has been accepted for inclusion in All Theses by an authorized administrator of TigerPrints. For more information, please contact [email protected]. HIGH-REDSHIFT BLAZARS THROUGH NuSTAR EYES A Thesis Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Master of Science Astrophysics by Lea Marcotulli May 2017 Accepted by: Dr. Marco Ajello, Committee Chair Dr. Dieter Hartmann Dr. Bradley Meyer Abstract MeV blazars are the most powerful sources among the blazar class. With bolometric luminosities exceeding 1048 erg s−1 and powerful relativistic jets, they are usually detected at high-redshifts (z > 2) and they generally harbor extremely massive black holes (M 109M ). Being able to derive their physical BH ∼ ⊙ properties such as jet power, accretion disk luminosity, bulk Lorentz factor of the jet (Γ) and black hole mass, enables us to put constraints in the understanding of this not well sampled class of objects and use them for example to probe the formation of massive black holes in the early universe. In this thesis we have analyzed the broadband emission of three high redshift blazars, focusing on the high energy part of their spectral energy distribution. In fact, being able to obtain hard X-ray data from the recently launched NuSTAR and having γ-ray detections from the Fermi-LAT, we were able to constrain more accurately the high energy peak of their distribution and therefore more precisely infer their jet power, underlying electron distribution, Γ and viewing angle (θv). Gathering optical and UV data allowed us to determine the black hole mass of such powerful objects as well as their accretion disk luminosity. This work has recently been published in ApJ (Marcotulli et al., 2017). In Section 1, the broad family of active galactic nuclei (ANGs) and their main physical characteristics are introduced, with a focus on the subclass of blazars and specifically MeV blazars. In Section 2, the main instruments used in our research to gatherand analyze data are described, with a particular interest on imaging in the hard X-ray regime. Section 3 contains the data analysis description, the results obtained combining the observations with a one-zone leptonic emission model and the discussion on our findings. In Section 4 we report our conclusions and present an outlook on future MeV blazars studies possibilities. Appendix A, B and C contain an overlook of relativistic beaming, radiative processes and model used for these sources. ii Acknowledgments Being in Clemson has given me many satisfactions, and writing this thesis is one of them. But for this to be achieved, I needed the help of some fantastic people that deserve a proper thank you. First Marco, my advisor, the best! Without you I wouldn’t be here in the first place and I couldn’t have had this great experience that has been living in the US. It’s thanks to your advices and mentoring that I could do everything here and start my carreer. You made everything look easier and worth to. Plus, I mean, which advisor takes his students for camping? You’re just great. Grazie infinatamente! I also want to thank my unofficial advisor, Vaidehi. ‘Handsome, smart, with a little bit of belly but no worries’, not only you basically thaught me everything I know about blazars, but also about monkeys and you have been a good friend as well. And thanks to our group: Aman, Abhishek, Stefano. Having your support makes everything easier and more fun. I also want to thank all professors that have dealt with me in the first year.. and after: Dieter, Brad and Tewari. I learnt and I keep learning a lot from all of you. I want to thank my friends in Clemson, that have become my family here throught these two years: Komal, Bipin, Subash, Prakash, P.K., Mihiri, Nick, Steve, Wren, Chuanchang. A particular thanks goes to Komal: without you I probably would have become crazy after the first few weeks of classes and teaching and I wouldn’t have enjoyed all of this. You have been a friend, a sis and sometimes also a mom. There is no way I can be in Clemson without you. Then to all three bros: with our laughter and crappy jokes, it was possible to forget everything and to move on from every good or bad week. I love y’all so much! iii And then of course there are all the people far away that have supported me since the first time I said I wanted to flea the country. Ma maman cherie ador´ee, that have always encouraged me for every choice in my life. My brother and my dad, that everytime something happens to me here, they spread the news in the whole Fermo. My friends, that even with 6 hours of time delay, always kept in touch as we were 5 minutes away and with whom I could swear in Italian everytime this town made me go nuts! Love, Mimmi, grazie! To conclude I just want to say that I am grateful that I had this chance in my life. The chance to find a good advisor, good professors, and good friends. The chance to feel at home even being a non resident alien. And even if this is a small step, I know that many others will come in the next years. I love you all very much! Thank you! iv Table of Contents Title Page ................................................. i Abstract .................................................. ii Acknowledgments ............................................ iii List of Tables ............................................... vi List of Figures .............................................. vii 1 Introduction ............................................. 1 1.1 Historical background and Observational characteristics .................... 1 1.2 Main AGN components ..................................... 4 1.3 Unification ........................................... 9 1.4 Blazars ............................................. 12 2 Facilities ............................................... 18 2.1 Imaging in the hard X-ray regime ............................... 18 2.2 The Nuclear Spectroscopic Telescope Array .......................... 24 2.3 Fermi Large Area Telescope (LAT) .............................. 26 2.4 Swift ............................................... 30 2.5 Gamma-Ray Burst Optical/Near-Infrared Detector ....................... 33 3 MeV Blazars through Nustar Eyes ................................. 35 3.1 Observations .......................................... 36 3.2 Results .............................................. 38 3.3 Discussion ............................................ 44 4 Conclusions and Outlook ...................................... 48 4.1 Conclusions ........................................... 48 4.2 Outlook ............................................. 49 Appendices ................................................ 51 A Relativistic Beaming ...................................... 52 B Radiative Processes ....................................... 58 C Modeling ............................................ 69 Bibliography ............................................... 76 v List of Tables 1.1 Table of AGN subclasses .................................... 10 2.1 Tableof NuSTAR optics parameters .............................. 24 2.2 Table of Observatory Performance Parameters (adapted from Harrison et al., 2013) ..... 26 2.3 Focal Plane Parameters (adapted from Harrison et al., 2013) ................. 26 2.4 LAT instrument parameters and Estimated Performance (adapted from Atwood et al., 2009) . 28 2.5 XRT instrument parameters (adapted from Burrows et al., 2005) ............... 32 2.6 UVOT instrument parameters (adapted from Roming et al., 2005) .............. 32 3.1 Table of Observations and Spectral Parameters ......................... 40 3.2 Summary of the parameters used/derived from the SED modeling of three MeV blazars ... 41 3.3 Table of Black-Hole Masses .................................. 44 vi List of Figures 1.1 Superluminal motion of M87 .................................. 3 1.2 A schematic of an AGN with relativistic jets .......................... 5 1.3 Keplerian disk around a black hole ............................... 7 1.4 Quasar spectrum ........................................ 7 1.5 Torus and jet emission from AGN ............................... 10 1.6 AGN unification ......................................... 12 1.7 Typical SED of a blazar ..................................... 13 1.8 Blazar sequence ......................................... 15 1.9 SEDs of high redshift blazars .................................. 16 2.1 Scanning collimators and Coded masks ............................ 20 2.2 X-ray reflectivities for different materials ........................... 21 2.3 Schematic of an X-ray mirror .................................. 22 2.4 Absorption efficiency of different materials .......................... 23 2.5 NuSTAR observatory diagram .................................. 24 2.6 Effective collecting area of NuSTAR .............................. 25 2.7 NuSTAR focal plane ...................................... 26 2.8 Schematic diagram of the Fermi-LAT instrument. ....................... 27 2.9 Fermi tracker array ......................................