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MCAIM Colloquium: Sheperd S. Doeleman, Harvard University, Founding Director of the Event Horizon Telescope
April 14, 2021 @ 4:00 pm - 5:00 pm
Talk Title: Black Hole Imaging: First Results and Future Vision
Abstract: In April 2017, the Event Horizon Telescope (EHT) carried out a global Very Long Baseline Interferometry (VLBI) observing campaign at a wavelength of 1mm that led to the first resolved image of a supermas- sive black hole. For the 6.5 billion solar mass black hole in the giant elliptical galaxy M87, the EHT estimated the spin orientation and constrained models of accretion on Schwarzschild radius scales. This work relied on two decades of technical advances in ultra-high resolution interferometry and theoretical General Relativistic Magnetohydrodynamic (GRMHD) simulations. This talk will review these advances and recent new EHT results.
We will also look to the next decade when a next-generation EHT (ngE-HT) that doubles the number of participating radio dishes in the VLBI net-work will enable time-lapse movies of M87 that link the black hole to the relativistic jet it powers. For SgrA*, the Galactic Center black hole that evolves on time scales 1000 times faster, ngEHT will produce real-time video.
Bio: Sheperd S. Doeleman is an Astrophysicist at the Center for Astrophysics | Harvard & Smithsonian and Founding Director of the Event Horizon Telescope (EHT), a synchronized global array of radio observatories designed to examine the nature of black holes. He is also a Harvard Senior Research Fellow and a Project Co-Leader of Harvard’s recently established Black Hole Initiative (BHI). The BHI is a first-of-its-kind interdisciplinary program at the University that brings together the disciplines of Astronomy, Physics, Mathematics, Philosophy, and History of Science to define and establish black hole science as a new field of study.
As one of the founding members of the BHI, Doeleman leads a team studying supermassive black holes with sufficient resolution to directly observe the event horizon itself. Using Very Long Baseline Interferometry (VLBI) methods, the EHT telescope networks observe astronomical radio sources at 1.3 millimeter (mm) wavelengths. These sources include the supermassive black holes at the centers of our own Milky Way, called Sagittarius A* (SgrA*), as well as in Messier 87 (M87), the supergiant elliptical galaxy in the constellation Virgo.
Doeleman is a Guggenheim Fellow (2012) and was the recipient of the DAAD German Academic Exchange grant for research at the Max Planck Institute für Radioastonomie. He serves as a peer reviewer for the Astrophysical Journal, Science, and Nature, among others. Doeleman leads and co-leads research programs supported by grants from the National Science Foundation, the National Radio Astronomy Observatory (NRAO) ALMA-NA Development Fund, the Smithsonian Astrophysical Observatory, the MIT International Science & Technology Initiatives (MISTI), the Gordon and Betty Moore Foundation, and the John Templeton Foundation. He has taught at MIT and mentors students and post-doctoral fellows at MIT and Harvard.
Doeleman received his B.A. from Reed College in 1986, and left soon after for a year in Antarctica where he conducted multiple space-science experiments at McMurdo Station on the Ross Ice Shelf. With an appreciation for the challenges and rewards of instrumental work in difficult circumstances, he returned to complete a Ph.D. in astrophysics at MIT. After visiting the Max Planck Institute as a recipient of the DAAD, he came back to MIT in 1995 for a postdoctoral fellowship, eventually serving as assistant director of the MIT Haystack Observatory.
Doeleman’s interests focus on problems in astrophysics that require ultra-high resolving power—the ability to observe fine details of cosmic objects. His research employs the technique of Very Long Baseline Interferometry (VLBI), in which widely separated radio dishes are combined to form an Earth-sized virtual telescope. He has used this technique to study the atmospheres of dying stars, as well as stars that are just being born. His group at MIT pioneered development of instrumentation that enables VLBI to achieve the greatest resolving power possible from the surface of the Earth. He carried out the first global experiments using these new systems that successfully measured the size of the supermassive black hole at the center of the Milky Way Galaxy and in the galaxy M87. He now directs the international Event Horizon Telescope project, whose goal is to image the event horizon of a black hole, the boundary where gravity is so strong that even light cannot escape. This project addresses several fundamental questions about the Universe: Do event horizons exist? Does Einstein’s theory of gravity hold near a black hole? How do black holes affect the evolution of galaxies?
Join Zoom Meeting: https://umich.zoom.us/j/98619190605
Meeting ID: 986 1919 0605
This event is hosted by the Michigan Center for Applied and Interdisciplinary Mathematics.