Avery Broderick

Research Interests

The goal of my research program is to elucidate the fundamental nature and astronomical consequences of astrophysical black holes. I do this via a number of independent projects, spanning scales from the horizon to the universe, each of which are connected by the critical role played by the extreme physical conditions near black hole horizons.

My current focus is the interpretation and analysis of horizon-resolving millimeter wave observations of the supermassive black holes at the centers of the Milky Way and M87. These observations provide unprecedented access to the immediate vicinity of the horizon, and therefore to the effects of strong gravity near black holes. Hence they provide an ideal opportunity to probe both the high-energy astrophysics powering some of the most energetic phenomena in the universe and test the validity of general relativity in the strongly non-linear limit. This work involves developing both the models and the analysis techniques, often combining the high-resolution radio data with additional observations in multiple wavebands, to extract answers to the physically relevant questions.

In addition, I am also involved with efforts to: Assess the cosmological impact of the very-high energy gamma ray emission from a subset of active galactic nuclei (AGNs, accreting supermassive black holes at the centers of galaxies), capable of heating the universe by orders of magnitude; Study the magnetic structure of the ultra-relativistic jets powered by AGN via coupling multi-wavelength polarization observations with state-of-the-art simulations; Probe the dynamics and potential signatures of white dwarf encounters with intermediate mass black holes, which show promise as a potential astronomical signature of the presence of this latter, heretofore undetected, class of black hole; and Measure the statistical properties of Galactic stellar-mass black holes, the end points of massive star evolution, via potentially directly imaging microlensing events.

Positions Held

• 2007 - 2011 Canadian Institute for Theoretical Astrophysics Senior Research Associate
• 2004 - 2007 Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics Institute for Theory and Computation Postdoctoral Fellow

Awards

• Beatrics D. Tremaine Fellow, Prize, Canadian Institute for Theoretical Astrophysics

Recent Publications

• Puchwein, E., Pfrommer, C., Springel, V., Broderick, A.E. and Chang, P. 2012. ``The Lyman-alpha forest in a blazar-heated Universe'', MNRAS, 423, 149-164
• Broderick, A.E., Chang, P. and Pfrommer, C. 2012. ``The Cosmological Impact of Luminous TeV Blazars I: Implications of Plasma Instabilities for the Intergalactic Magnetic Field and Extragalactic Gamma-Ray Background'', ApJ, 752, 22 (23pp)
• Chang, P., Broderick, A.E. and Pfrommer, C. 2012. ``The Cosmological Impact of Luminous TeV Blazars II: Rewriting the Thermal History of the Intergalactic Medium'', ApJ, 752, 23 (24pp)
• Pfrommer, C., Chang, P. and Broderick, A.E. 2012. ``The Cosmological Impact of Luminous TeV Blazars III: Implications for Galaxy Clusters and the Formation of Dwarf Galaxies'', ApJ, 752, 24 (21pp)
• Broderick, A.E., Fish, V.L., Doeleman, S.S. and Loeb, A. 2011. ``Constraining the Structure of Sagittarius A*'s Accretion Flow with Millimeter-VLBI Closure Phases'', ApJ, 738, 38 (8pp)
• Broderick, A.E., Fish, V.L., Doeleman, S.S. and Loeb, A. 2011. ``Evidence for Low Black Hole Spin and Physically Motivated Accretion Models from Millimeter-VLBI Observations of Sagittarius A*'', ApJ, 735, 110 (15pp)
• Broderick, A.E., Loeb, A. and Reid, M.J. 2011. ``Localizing Sagittarius A* and M87 on Microarcsecond Scales with Millimeter Very Long Baseline Interferometry'', ApJ, 735, 57 (18pp)
• Broderick, A.E. and McKinney, J.C. 2010. ``Parsec-scale Faraday Rotation Measures from General Relativistic Magnetohydrodynamic Simulations of Active Galactic Nucleus Jets'', ApJ, 725, 750-773
• Broderick, A.E. and Keto, E. 2010. ``The Evolution of Cloud Cores and the Formation of Stars'', ApJ, 721, 493-504
• Broderick, A.E. and Blandford, R.D. 2010. ``Understanding the Geometry of Astrophysical Magnetic Fields'', ApJ, 718, 1085-1099
• Fish, V.L., Doeleman, S.S., Broderick, A.E., Loeb, A. and Rogers, A.E.E. 2009. ``Detecting Changing Polarization Structures in Sagittarius A* with High Frequency VLBI'', ApJ, 706, 1353-1363
• Broderick, A.E. and Loeb, A. 2009. ``Signatures of Relativistic Helical Motion in the Rotation Measures of Active Galactic Nucleus Jets'', ApJL, 703, L104-L108
• Broderick, A.E., Loeb, A. and Narayan, R. 2009. ``The Event Horizon of Sagittarius A*'', ApJ, 701, 1357-1366
• Broderick, A.E. and Loeb, A. 2009. ``Imaging the Black Hole Silhouette of M87: Implications for Jet Formation and Black Hole Spin'', ApJ, 697, 1164-1179
• Broderick, A.E., Fish, V.L., Doeleman, S.S. and Loeb, A. 2009, ``Estimating the Parameters of Sagittarius A*'s Accretion Flow Via Millimeter VLBI'', ApJ, 697, 45-54
• Doeleman, S.S., Fish, V.L., Broderick, A.E., Loeb, A. and Rogers, A.E.E. 2009. ``Detecting Flaring Structure in Sagittarius A* with High-Frequency VLBI'', ApJ, 695, 59-74
• Fish, V.L., Broderick, A.E., Doeleman, S.S. and Loeb, A. 2009. ``Using Millimeter VLBI to Constrain RIAF Models of Sagittarius A*'', ApJL, 692, L14-L18
• Broderick, A.E., Narayan, R., Keto, E. and Lada, C.J. 2008. ``The Damping Rates of Embedded Oscillating Starless Cores'', ApJ, 682, 1095-1102
• Reid, Mark J., Broderick, A.E., Loeb, A., Honma, M. and Brunthaler, A. 2008. ``Limits on the Position Wander of Sgr A*'', ApJ, 682, 1041-1046
• Broderick, A.E. and Narayan, R. 2008. ``Magnetic helicity and the relaxation of fossil fields'', MNRAS, 383, 943-956
• Broderick, A.E., Keto, E., Lada, C.J. and Narayan, R. 2007. ``Oscillating Starless cores: The Nonlinear Regime'', ApJ, 671, 1832-1838
• Broderick, A.E. and Narayan, R. 2007. ``Where are all the gravastars? Limits upon the gravastar model from accreting black holes'', CQG, 24, 659-666
• Keto, E., Broderick, A.E., Lada, C.J. and Narayan, R. 2006. ``Oscillations of Starless Cores'', ApJ, 652, 1366-1373
• Broderick, A.E. and Rathore, Y. 2006. ``A multidimensional, adiabatic hydrodynamics code for studying tidal excitation'', MNRAS, 372, 923-932
• Broderick, A.E. and Loeb, A. 2006. ``Imaging optically-thin hotspots near the black hole horizon of Sgr A* at radio and near-infrared wavelengths'', MNRAS, 367, 905-916
• Broderick, A.E. 2006. ``Radiative transfer along rays in curved space-times'', MNRAS, 366, L10-L12
• Broderick, A.E. and Narayan, R. 2006. ``On the Nature of the Dark Mass at the Galactic Center'', ApJL, 638, L21-L24
• Broderick, A.E. and Loeb, A. 2006. ``Frequency-dependent Shift in the Image Centroid of the Black Hole at the Galactic Center as a Test of General Relativity'', ApJL, 636, L109-L112
• Broderick, A.E. and Loeb, A. 2005. ``Imaging bright-spots in the accretion flow near the black hole horizon of Sgr A*'', MNRAS, 363, 353-362
• Broderick, A.E. 2005. ``Supernovae in helium star--compact object binaries: a possible gamma-ray burst mechanism'', MNRAS, 361, 955-964
• Rathore, Y., Blandford, R. and Broderick, A.E. 2005. ``Resonant excitation of white dwarf oscillations in compact binaries --I. The no back reaction approximation'', MNRAS, 357, 834-846
• Broderick, A.E. & Blandford, R. 2004. ``Covariant magnetoionic theory -- II. Radiative transfer'', MNRAS, 349, 994
• Broderick, A.E. & Blandford, R. 2003. ``Covariant magnetoionic theory -- I. Ray propagation'', MNRAS, 342, 1280
• Rathore, Y., Broderick, A.E. & Blandford, R. 2003. ``A variational formalism for tidal excitation: non-rotating, homentropic stars'', MNRAS, 339, 25
• Broderick, A.E., Prakash, M. & Lattimer, J.M. 2002. ``Effects of strong magnetic fields in strange baryonic matter'', Phys. Lett. B, 531, 167
• Broderick, A., Prakash, M. & Lattimer, J.M., 2000. ``The Equation of State of Neutron Star Matter in Strong Magnetic Fields'', ApJ, 537, 351
• "Implications of Plasma Beam Instabilities for the Statistics of the Fermi Hard Gamma-ray Blazars and the Origin of the Extragalactic Gamma-Ray Background", Broderick, A.E., Pfrommer, C., Puchwein, E., and Chang, P., arXiv: 1308.0340
• "Lower Limits upon the Anisotropy of the Extragalactic Gamma-Ray Background implied by the 2FGL and 1FHL Catalogs", Broderick, A.E., Pfrommer, C., Puchwein, E., and Chang, P., arXiv: 1308.0015
• Recontres de Moriond 2013: Very High Energy Phenomena in the Universe Pfrommer, C., Broderick, A.E., Chang, P. Puchwein, E. Springel, V., arXiv: 1308.6284
• Fish, V.L., Doeleman, S.S., Broderick, A.E., Loeb, A. and Rogers, A.E.E. 2008. ``Detecting Flaring Structures in Sagittarius A* with (Sub)Millimeter VLBI'', XXIX URSI General Assembly (Chicago), arXiv: 0807.2427
• Broderick, A.E. and Loeb, A. 2006. ``Testing General Relativity with High-Resolution Imaging of Sgr A*'', From the Center of the Milky Way to Nearby Low-Luminosity Galactic Nuclei, Journal of Physics: Conference Series ed. R. Schodel, G.C. Bower, M.P. Muno, S. Nayakshin and T. Ott (Philadelphia: Institute of Physics Publishing), 54, 448-455
• Broderick, A.E. and Loeb, A. 2009. ``Shedding Light on Darkness: Imaging Black Hole Silhouettes'', Scientific American, December, 2009, 42-50

Seminars

• "Resolving Black Holes with the Event Horizon Telescope", GR20/Amaldi10 (Warsaw)
• "Black Hole Imaging Horizons", Wunch Talk (Princeton)
• "Imaging Supermassive Black Holes on Horizon Scales", Colloquium (Western University)
• "Imaging Supermassive Black Holes on Horizon Scales", Joint Astronomical Colloquium (ZfA, HITS, MPA; Heidelberg)
• "VLBI observations of jets in M87", Fermi Bubbles Workshop (KIPAC)
• "Imaging Supermassive Black Holes on Horizon Scales", Colloquium (University of Victoria)
• "Imaging Supermassive Black Holes on Horizon Scales", Colloquium (Simon Fraser University)
• "Imaging Supermassive Black Holes on Horizon Scales", Colloquium (Rochester University)
• "Imaging Supermassive Black Holes on Horizon Scales", Colloquium (University of British Columbia)
• "Imaging Supermassive Black Holes on Horizon Scales", Astro Seminar (Michigan State University)
• "Modeling M87 on Horizon Scales for the EHT", Workshop on the Greenland telescope (Cambridge, MA)
• "Imaging Supermassive Black Holes on Horizon Scales", Colloquium (McMaster University)
• "Testing GR with Imaging of SMBHs, part deux", Testing General Relativity with Astrophysical Systems (Cambridge)
• "Early Results from the Event Horizon Telescope: Shedding light on the gastronomy and hair styles of black holes", Theoretical Physics Workshop (Western)
• "Imaging Black Holes", APS Invited Session: Homing in on the Galactic Center Black Hole (Atlanta)
• "Resolving Horizon Physics with Millimetre-wave VLBI", The Future of mm/submm Astronomy in Canada (Dunlap Institute, Toronto)
• "Doughnuts, pancakes, and other black hole breakfast items: Constraining low-luminosity accretion physics with the EHT", Bringing Black Holes into Focus (Tucson)
• "The Dog Who Didn't Bark: Missing Gamma Rays and the Cosmological Impact of Plasma Instabilities", Astro Seminar (Waterloo)
• ``Imaging Black Hole Horizons with the Event Horizon Telescope'', The Central Kiloparsec in Galactic Nuclei: Astronomy at High Angular Resolution 2011 (Bad Honnef)
• ``Imaging Black Hole Horizons: Probing the Nature and Habits of Black Holes'', JSI Seminar (University of Maryland)
• ``Probing the Gastronomy of Supermassive Black Holes with High and Ultra-High Resolution Imaging'', Physics & Astronomy Colloquium (University of Waterloo)
• ``Imaging Black Hole Horizons: Probing the Nature and Habits of Black Holes'', Tapir Seminar (Caltech)
• ``The Life and Times of Black Holes and Other Stories: Research Topics in Compact Object Astrophysics'', Astrophysics Lunch Talk (University of Pittsburgh)
• ``The Event Horizon Telescope: Imaging Black Hole Horizons'', Physics \& Astronomy Colloquium (University of Pittsburgh)
• ``The Hairstyles of Compact Objects'', Theory Meets Data Analysis at Comparable and Extreme Mass Ratios, CAPRA+NRDA Meeting (Perimeter Institute)
• ``Measuring the Geometry of AGN Core Magnetic Fields'', Rotation Measure Analysis of Magnetic Fields in and around Radio Galaxies (Riccione, Italy)
• ``Staring into the Abyss: Imaging Black Hole Horizons'', Special SAO Colloquium (CfA)
• ``Imaging Black Hole Horizons'', Formation and Evolution of Black Holes, 2010 Winter Conference on Astrophysics (Aspen Center for Physics)
• ``Staring into the Abyss: Imaging Black Hole Horizons'', Joint Astrophysics Colloquium (McGill University)
• ``Nature of the black hole in the center of the Milky Way'', APS Invited Session: Probing strong-field gravity with observations of the galactic center black hole, (Washington D.C.)
• ``Staring into the Abyss: Imaging Black Hole Horizons'', Astro Seminar (NYU)
• ``To the Edge and Back: Directly Imaging the Horizon of a Black Hole'', Royal Astronomical Society of Canada
• ``Staring Into the Abyss: Directly Imaging Black Hole Event Horizons'', Physics Colloquium (University of Guelph)
• ``Imaging Nearby Black Holes: Providing a window on accretion, jet formation and general relativity'', Astronomy Colloquium (Columbia University)
• ``The Nature of Sagittarius A*'', AAS Special Session: Getting to the Event Horizon: Sgr A* (Long Beach)
• ``Directly Imaging the Horizons of Black Holes'', Astrophysics Colloquium (MIT)
• ``A New Window on Jet Formation: Millimeter & Submillimeter VLBI'', 213th AAS Meeting (Long Beach)
• ``Imaging Black Hole Horizons'', Special Colloquium (Northwestern Univsersity)
• ``Imaging Horizons'', Astrophysics with Radio and Gravitational-Wave Observatories (Charlottesville)
• ``On the Horizon: Imaging Nearby Black Holes'', ACKS Seminar (Kavli Institute for Particle Astrophysics and Cosmology, Stanford)
• ``On the Horizon: Imaging Nearby Black Holes'', INPP+API Seminar (Ohio University)
• ``At the horizon: Imaging black holes and testing general relativity'', Astronomy Colloquium (University of Illinois)
• ``At the horizon: Imaging black holes and testing general relativity'', Astronomy Colloquium (University of Chicago)
• ``Testing the Kerr Metric: Confronting Strong Field Relativity with Observations'', Physics Colloquium (Georgia Tech)
• `Microarcsecond imaging of Sgr A*: A way to test the Kerr metric'', Special Theoretical Astrophysics Seminar (Northwestern University)
• ``Imaging the Central Black Hole in the Milky Way'', Rethinking Gravity: From the Planck scale to the size of the Universe (Tuscon)
• ``Microarcsecond imaging of Sgr A*: A way to test the Kerr metric'', CITA Seminar (Canadian Institute for Theoretical Astrophysics)
• ``Testing the Kerr Metric with Micro-Arcsecond Imaging of Sgr A*'', XXIII Texas Symposium on Relativistic Astrophysics (Melbourne)
• ``Microarcsecond Imaging of Sgr A* and Testing General Relativity'', RAL Seminar (UC Berkeley)
• ``Radio Imaging of Sgr A*'', New Results on the Galactic Centre (XXVI IAU General Assembly, Prague)
• ``Testing General Relativity with Images of Sgr A*'', The History of Nuclear Black Holes in Galaxies (Cambridge)
• ``The possibility of testing general relativity with high-resolution imaging of Sgr A*'', Galactic Center Workshop 2006 (Bad Honnef)
• ``Circular Polarisation from Tangled Magnetic Fields'', Institute of Astronomy Seminar (Cambridge University)
• ``Polarization Effects Near Black Holes'', X-ray Polarimetry Workshop (SLAC)
• ``Covariant Magnetoionic Theory (CP Production in BH Accretion Flows)'', TAC Seminar (UC Berkeley)
• ``Circular Polarization in Black Hole Accretion Flows (The Role of Refraction)'', AAS Meeting (Atlanta)
• ``General Relativistic Magnetoionic Theory'', Circular Polarisation from Relativistic Jet Sources (University of Amsterdam)
• ``General Relativistic Magnetoionic Theory and Low Luminosity AGN'', Theoretical Astrophysics in Southern California (California Institute of Technology)
• PIRSA:12020127, The Other 99%: The Life and Times of the Black Hole Next Door, 2012-02-15, Colloquium
• PIRSA:12020146, The Tyranny of Scale: Making Simple Problems Hard, 2012-02-09, Workshop: Computational Methods at Perimeter
• PIRSA:11110126, Researcher Presentation: Avery Broderick, 2011-11-23, 11/12 PSI - Researcher Presentations
• PIRSA:11100105, Portrait of a Black Hole, 2011-10-14, Conceptual Gems of Theoretical Physics
• PIRSA:11100082, Rewriting the Thermal History of the Universe: The Cosmological Implications of TeV Blazars, 2011-10-11, Cosmology & Gravitation
• PIRSA:11010115, The Event Horizon Telescope: Imaging Black Hole Horizons, 2011-01-31, Cosmology & Gravitation
• PIRSA:10060088, The Hairstyles of Compact Objects, 2010-06-26, Theory Meets Data Analysis at Comparable and Extreme Mass Ratios