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Measurement of Black Hole Masses in Active Galactic Nuclei

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Measurement of Black Hole Masses in Active Galactic Nuclei Measurement of Black Hole Masses in Active Galactic Nuclei DISSERTATION Presented in Partial Ful¯llment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Christopher A. Onken ***** The Ohio State University 2005 Dissertation Committee: Approved by Professor Bradley M. Peterson, Adviser Professor Richard W. Pogge Adviser Astronomy Graduate Program Professor Smita Mathur ABSTRACT We investigate the calibration and application of reverberation mapping techniques for determining black hole (BH) masses in active galactic nuclei (AGNs). We present revised BH mass determinations for several AGNs based on the use of updated methodologies with archival data, demonstrating signi¯cant reductions in the sizes of the BH mass uncertainties. Moreover, the study of the Seyfert 1 galaxy, NGC 3783, shows that the gas in the broad-line region of this AGN obeys the virial theorem. We use measurements of stellar velocity dispersions, σ¤, in AGNs and the assumption that AGNs follow the same relation between BH mass and σ¤ as quiescent galaxies to provide the ¯rst empirical calibration for reverberation-based BH masses. We also attempt to determine an independent calibration of these masses by studying the reverberation-mapped AGN, NGC 4151, with ground- and space-based observations, and by trying to constrain the BH mass through modeling of the galaxy's stellar dynamics. We estimate the BH masses and bolometric luminosities in 400 AGNs » selected from the multi-wavelength AGN and Galaxy Evolution Survey (AGES), ii where the BH masses are calculated from scaling relationships that have grown out of reverberation mapping. We ¯nd the distribution of Eddington ratios at ¯xed luminosity to be sharply peaked around a value of 1/3, with a dispersion of just 0.3 dex. The distribution of Eddington ratios at ¯xed mass looks to be similarly narrow, and we are able to con¯rm a drop in the underlying distribution at low Eddington ratios for certain combinations of redshift and BH mass|all previous studies in these redshift mass bins are a®ected by selection e®ects at low Eddington ¡ ratio (as are the AGES data in lower mass or higher redshift bins). The dominance of AGN accretion at rates relatively close to the Eddington limit has important implications for the growth of BHs and the joint evolution of BHs and their host galaxies. iii Dedicated to all the helping hands along the way... the ones who guided and the ones who pushed. iv ACKNOWLEDGMENTS Innumerable people deserve to be acknowledged for their influence, personal and professional, on the incredible experience I have had. Thank you to my adviser, Brad Peterson, for taking a fellow Minnesotan under your wing and showing me how to work as an astronomer. Thanks to Rick Pogge for your willingness to share your time and encyclopedic knowledge of topics astrophysical and otherwise. Thank you to all of the Astronomy Department faculty members, postdocs, and sta® at The Ohio State University{I've pestered every one of you with questions at some time over the last ¯ve years and you have all been willing to stop whatever you were doing and provide me with answers. To the OSU faculty with whom I've been fortunate enough work directly (in chronological order: Darren DePoy, Don Terndrup, Brad, Jordi Miralda-Escud¶e, Smita Mathur, Rick, Chris Kochanek, Andy Gould, and David Weinberg), I thank you for fostering my development as a scientist. And to the postdocs who have given me so much guidance, Marianne Vestergaard and Matthias Dietrich, thank you for your help. To my fellow OSU grad students, I am grateful to call all of you my friends. The space it would take to explain your importance to my time in Columbus would v double the size of this document. Let me simply say that you are a magni¯cent bunch of people, and I look forward to seeing all of you again. Prior to my arrival in Columbus, I bene¯ted from the advice and instruction o®ered by several people. I am indebted to Evan Skillman, who kindly took the time to answer question after question in Intro Astronomy and in the years that followed; and to Ted Bowell, Bruce Koehn, and Brian Ski®, who gave me my ¯rst taste of observing; and to David Alves and Howard Bond, who sparked continuing research interests that are beyond the scope of this dissertation; and to John Dickey, who both demonstrated how to be an e®ective teacher and patiently advised me on my senior thesis; and to Terry Jones, who ¯rst suggested applying to OSU for grad school. Finally, I am pleased to be able to acknowledge the role of my wonderful family. Without your love, interest, and support, I never would have come so far. Thank you. vi VITA August 14, 1978 . Born { Spring¯eld, IL, USA 2000 . B.S., Physics (magna cum laude), University of Minnesota 2000 . B.S., Astrophysics (summa cum laude), University of Minnesota 2000 { 2005 . Graduate Teaching and Research Associate, The Ohio State University 2003 . M.S., The Ohio State University PUBLICATIONS Research Publications 1. H. E. Bond, D. R. Alves, and C. Onken, \CCD Photometry of the Globular Cluster NGC 5986 and Its Post-Asymptotic Giant Branch and RR Lyrae Stars", AJ, 121, 318, (2001). 2. C. A. Onken, and B. M. Peterson, \The Mass of the Central Black Hole in the Seyfert Galaxy NGC 3783", ApJ, 572, 746, (2002). 3. B. M. Peterson, et al. (41 authors, incl. C. A. Onken), \Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XVI. A 13 Year Study of Spectral Variability in NGC 5548", ApJ, 581, 197, (2002). vii 4. C. A. Onken, B. M. Peterson, M. Dietrich, A. Robinson, and I. M. Salamanca, \Black Hole Masses in Three Seyfert Galaxies", ApJ, 585, 121, (2003). 5. C. A. Onken, and J. Miralda-Escud¶e, \History of Hydrogen Reionization in the Cold Dark Matter Model", ApJ, 610, 1, (2004). 6. B. M. Peterson et al. (12 authors, incl. C. A. Onken), \Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database", ApJ, 613, 682, (2004). 7. C. A. Onken, L. Ferrarese, D. Merritt, B. M. Peterson, R. W. Pogge, M. Vestergaard, and A. Wandel, \Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the Black Hole Mass-Velocity Dispersion Relationship for Active Galactic Nuclei", ApJ, 615, 645, (2004). FIELDS OF STUDY Major Field: Astronomy viii Table of Contents Abstract . ii Dedication . iv Acknowledgments . v Vita . vii List of Tables . xii List of Figures . xiv Chapter 1 Introduction 1 1.1 Active Galactic Nuclei . 1 1.2 Reverberation Mapping . 3 1.2.1 Time Delay . 4 1.2.2 Velocity Width . 9 1.2.3 BH Mass . 10 1.3 Stellar Dynamical BH Masses . 11 1.4 Scaling Relations . 14 1.5 Focus of This Study . 16 1.6 Published Work . 18 Chapter 2 Reverberation Mapping of NGC 3783 23 ix 2.1 Introduction . 23 2.2 Data . 24 2.2.1 UV Data . 24 2.2.2 Optical Data . 26 2.3 Methods and Techniques . 28 2.3.1 Spectral Analysis . 28 2.3.2 Light Curve Analysis . 29 2.4 Results . 30 2.4.1 Line widths . 30 2.4.2 Time delays . 30 2.5 Discussion . 33 Chapter 3 Additional Reverberation Mapping Studies 70 3.1 Introduction . 70 3.2 Observations and Data Reduction . 71 3.2.1 NGC 3227 . 72 3.2.2 NGC 3516 . 73 3.2.3 NGC 4593 . 74 3.3 Analysis . 75 3.4 Mass Calculations . 76 3.4.1 NGC 3227 . 77 3.4.2 NGC 3516 . 77 3.4.3 NGC 4593 . 78 3.5 The BH Mass|Stellar Velocity Dispersion Relationship . 78 x 3.6 Conclusion . 80 Chapter 4 The Black Hole Mass Stellar Velocity Dispersion Relation ¡ for AGNs 89 4.1 Introduction . 89 4.2 Observations and Data Reduction . 91 4.2.1 Data Reduction and Analysis . 93 4.3 Results and Discussion . 94 4.3.1 Measuring Velocity Dispersions . 94 4.3.2 Measuring Virial Products . 95 4.3.3 The BH Mass{Velocity Dispersion Relation . 96 4.3.4 BLR Models . 100 4.3.5 Gravitational Redshifts . 101 4.3.6 Velocity Dispersion Versus FWHM([O III]¸5007 A)º . 103 4.4 Conclusion . 104 Chapter 5 Stellar Dynamics of NGC 4151 113 5.1 Introduction . 113 5.2 Stellar Dynamics Overview . 115 5.3 Imaging . 117 5.3.1 ACS/HRC . 118 5.3.2 MDM . 118 5.4 Spectroscopy . 119 5.4.1 HST/STIS ToO . 120 5.4.2 Ground-based . 122 xi 5.5 Analysis & Results . 125 5.5.1 Surface Brightness Pro¯le Modeling . 125 5.5.2 Gauss-Hermite Parameter Estimation . 129 5.5.3 Orbit Modeling . 131 5.6 Discussion . 133 Chapter 6 Black Hole Masses and Eddington Ratios at 0:3 < z < 4 156 6.1 Introduction . 156 6.2 Data . 158 6.2.1 Completeness . 160 6.3 Analysis . 162 6.3.1 Line Width . 163 6.3.2 Continuum Luminosity . 166 6.3.3 Calibrating the Mg IIRelation . 167 6.3.4 Bolometric Luminosity Calculation . 168 6.4 Results . 169 6.4.1 Luminosity-Redshift Bins . 171 6.4.2 Mass-Redshift Bins . 175 6.5 Discussion . 179 Chapter 7 Conclusion 197 7.1 Future Work . 200 Bibliography 202 xii List of Tables 2.1 NGC 3783 Continuum and Emission Line.
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