COVID-19 information for PI Residents and Visitors
The Event Horizon Telescope is the first astronomical instrument capable of imaging the horizon of a known black hole. By assembling a global network of existing millimetre and sub-millimetre wavelength observatories, the EHT can access the extraordinary resolutions required via Very Long Baseline Interferometry. Already it has detected horizon scale structure around the supermassive black holes at the centre of the Milky Way and the giant elliptical galaxy M87.
This is the second in a conference series designed to bring together the full EHT community, from instrument builders to theoretical modellers, for the purpose of fully exploiting the unique opportunities that the EHT provides. The goals of this conference will be:
- Describe the broad scientific context of astrophysical black holes and its relationship to EHT observations, including how the EHT can provide insight into systems ranging from pulsars to galaxy clusters by probing accretion and energetic outflows on the scale of the Schwarzschild radius.
- Discuss developments in our understanding of the astrophysics of the initial EHT
targets: the supermassive black holes at the centre of the Milky Way (Sgr A*) and M87. - Present new EHT-driven results.
- Describe the current technical status and discuss the planned development of the EHT, including the imminent inclusion of the Atacama Large Millimeter/submillimeter Array and the South Pole Telescope.
- Discuss the EHT collaboration and organize the EHT community.
Registration for this conference is now closed.
The Event Horizon Telescope has been made possible by support from:
EHT 2014 has received additional support from:
Avery Broderick, Perimeter Institute & University of Waterloo
Jim Cordes, Cornell University
Shep Doeleman, MIT Haystack Observatory
Stefan Gillessen, Max Planck Institute for Extraterristrial Physics
Gabriela Gonzalez, Louisiana State University
Michael Kramer, Max Planck Institute for Radio Astronomy
Colin Lonsdale, MIT Haystack Observatory
Samir Mathur, Ohio State University
Jeff McClintock, Harvard Smithsonian Center for Astrophysics
Dimitrios Psaltis, University of Arizona
Marta Volonteri, Paris Institute of Astrophysics
John Wardle, Brandeis University
- Kazunori Akiyama, National Astronomical Observatory of Japan
- Keiichi Asada, Academia Sinica Institute of Astronomy and Astrophysics
- James Bardeen, University of Washington
- Lindy Blackburn, Harvard Smithsonian Center for Astrophysics
- Katie Bouman, Massachusetts Institute of Technolgy
- Geoff Bower, Academia Sinica Institute of Astronomy and Astrophysics
- Christiann Brinkerink, Radboud University Nijmegen
- Roger Brissenden, Harvard Smithsonian Center for Astrophysics
- Avery Broderick, Perimeter Institute & University of Waterloo
- Thomas Bronzwaer, Radboud University Nijmegen
- Alejandro Cardenas-Avendano, Universidad Nacional de Colombia
- Andrew Chael, Harvard-Smithsonian Center for Astrophysics
- Laura Chajet, York University
- Pierre Christian, Harvard Smithsonian Center for Astrophysics
- Riley Connors, University of Amsterdam
- Jim Cordes, Cornell University
- Geoffrey Crew, MIT Haystack Observatory
- Roger Deane, University of Cape Town
- Jason Dexter, University of California, Berkeley
- Shep Doeleman, MIT Haystack Observatory
- Salome Dibi, Radboud University Nijmegen
- Frank Eisenhauer, Max Planck Institute for Extraterristrial Physics
- Heino Falcke, Radboud University Nijmegen
- Vincent Fish, MIT Haystack Observatory
- Seth Fletcher, Scientific American
- Robert Freund, University of Arizona
- Valeri Frolov, University of Alberta
- Charles Gammie, University of Illinois
- Andrea Ghez, University of California, Division of Astronomy & Astrophysics
- Stefan Gillessen, Max Planck Institute for Extraterristrial Physics
- Ciriaco Goddi, Radboud University Nijmegenz
- Roman Gold, Univeristy of Maryland
- Jose L. Gomez, Instituto Astrofisica Andalucia-CSIC
- Stephen Green, Perimeter Institute
- Kayhan Gultekin, University of Michigan
- Kazuhiro Hada, National Astronomical Observatory of Japan
- Michael Hecht, MIT Haystack Observatory
- Mareki Honma, National Astronomical Observatory of Japan
- David Hughes, INAOEP
- Makoto Inoue, Academia Sinica Institute of Astronomy and Astrophysics
- Britt Jeter, University of Waterloo
- Tim Johannsen, Perimeter Institute
- Michael Johnson, Harvard-Smithsonian Center for Astrophysics
- Svetlana Jorstad, Boston University
- Mansour Karami, Perimeter Institute
- Junhan Kim, Univeristy of Arizona
- Motoki Kino, Korea Astronomy and Space Science Institute
- Serguei Komissarov, University of Leeds
- Thomas Krichbaum, Max Planck Institute for Radio Astronomy
- Michael Kramer, Max Planck Institute for Radio Astronomy
- Kara Kundert, University of Michigan
- Robert Laing, European Southern Observatory
- Michael Landry, LIGO Hanford Observatory
- Luis Lehner, Perimeter Institute
- Laurent Loinard, CRyA-UNAM
- Colin Lonsdale, MIT Haystack Observatory
- Sera Markoff, University of Amsterdam
- Dan Marrone, University of Arizona
- Alan Marscher, Boston University
- Ivan Marti-Vidal, Onsala Space Observatory
- Samir Mathur, Ohio State University
- Satoki Matsushita, Academia Sinica Institute of Astronomy and Astrophysics
- Jeff McClintock, Harvard Smithsonian Center for Astrophysics
- Jonathan McKinney, University of Maryland
- Brian McNamara, University of Waterloo
- John Moffat, Perimeter Institute
- John Monnier, University of Michigan
- Monika Moscibrodzka, Radboud University Nijmegen
- Neil Nagar, University of Concepción
- Masanori Nakamura, Academia Sinica Institute of Astronomy and Astrophysics
- Gopal Narayanan, University of Massachusetts
- Monica Orienti, INAF-IRA
- Gisela Ortiz, Universidad Nacional Autónoma de México
- Nestor Ortiz, Perimeter Institute
- Dick Plambeck, University of California, Berkeley
- Dimitrios Psaltis, University of Arizona
- Hung-Yi Pu, Academia Sinica Institute of Astronomy and Astrophysics
- Eliot Quataert, University of California, Berkeley
- Luciano Rezzolla, Institute for Theoretical Physics
- Angelo Ricarte, Yale University
- Freek Roelofs, Radboud University Nijmegen
- Eduardo Ros, Max Planck Institute for Radio Astronomy
- Alan Roy, Max Planck Institute for Radio Astronomy
- Olivier Sarbach, Universidad Michoacana de San Nicolas de Hidalgo
- Mohamad Shalaby, Perimeter Institute
- Xavier Siemens, University of Wisconsin-Milwaukee
- Fumie Tazaki, National Astronomical Observatory of Japan
- Alexander Tchekhovskoy, University of California, Berkeley
- Remo Tilanus, Radboud University Nijmegen
- Neil Turok, Perimeter Institute
- Ilse Van Bemmel, JIVE
- Laura Vertatschitsch, Harvard Smithsonian Center for Astrophysics
- Marta Volonteri, Paris Institute of Astrophysics
- Jonelle Walsh, Texas A&M University
- Carlos Wang, University of Waterloo
- John Wardle, Brandeis University
- Jonathan Weintroub, Harvard Smithsonian Center for Astrophysics
- Huan Yang, Perimeter Institute
- Andre Young, Stellenbosch University
- Thomas Zannias, Universidad Michoacana de San Nicolas de Hidalgo
- Anton Zensus, Max Planck Institute for Radio Astronomy
Schedule is subject to change
Poster Session:
Participants have been encouraged to present posters; they will be displayed in the Atrium for the duration of the conference.
Monday, November 10, 2014
Time |
Event |
Location |
8:30 – 9:00am |
Registration |
Reception |
9:00 - 9:05am | Neil Turok, Perimeter Institute Welcome to Perimeter Institute and EHT 2014 |
Theater |
9:05 – 9:30am |
Shep Doeleman, MIT Haystack Observatory |
Theater |
9:30 – 9:55am |
Marta Volonteri, Paris Institute of Astrophysics |
Theater |
9:55 – 10:20am |
Jonathan McKinney, University of Maryland |
Theater |
10:20 – 10:45am |
Coffee Break |
Bistro – 1st Floor |
10:45 – 11:10am |
Andrea Ghez, |
Theater |
11:10 – 11:35am |
Sera Markoff, University of Amsterdam |
Theater |
11:35 – 12:00pm |
Geoff Bower, |
Theater |
12:00 – 12:25pm |
Eliot Quataert, University of California, Berkeley |
Theater |
12:25 – 1:00pm |
Charles Gammie, University of Illinois |
Theater |
1:00 – 2:30pm |
Lunch |
Bistro – 2nd Floor |
2:30 – 2:55pm |
Vincent Fish, MIT Haystack Observatory |
Theater |
2:55 – 3:20pm |
Michael Johnson, |
Theater |
3:20 – 3:45pm |
John Monnier, University of Michigan |
Theater |
3:45 – 4:15pm |
Coffee Break |
Bistro – 1st Floor |
4:15 - 4:45pm | Poster Blast | Theater |
4:45 – 6:00pm |
Avery Broderick, Perimeter Institute & University of Waterloo |
Theater |
Tuesday, November 11, 2014
Time |
Event |
Location |
9:00 – 9:25am |
Heino Falcke, Radboud University Nijmegen |
Theater |
9:25 – 9:50am |
Serguei Komissarov, University of Leeds |
Theater |
9:50 – 10:15am |
Jeff McClintock, Harvard Smithsonian Center for Astrophysics |
Theater |
10:15 – 10:45am |
Coffee Break |
Bistro – 1st Floor |
10:45 – 11:10am |
Masanori Nakamura, |
Theater |
11:10 – 11:35am |
Kayhan Gultekin, University of Michigan |
Theater |
11:35 – 12:00pm |
Monika Moscibrodzka, Radboud University Nijmegen |
Theater |
12:00 – 12:25pm |
Keiichi Asada, |
Theater |
12:25 – 1:00pm |
John Wardle, Brandeis University |
Theater |
1:00 – 2:30pm |
Lunch |
Bistro – 2nd Floor |
2:30 – 2:55pm |
Thomas Krichbaum, |
Theater |
2:55 – 3:20pm |
Avery Broderick, Perimeter Institute & University of Waterloo |
Theater |
3:20 – 3:45pm |
Kazunori Akiyama, |
Theater |
3:45 – 4:15pm |
Alexander Tchekhovskoy, University of California, Berkeley |
Bistro – 1st Floor |
4:15 – 4:45pm |
Coffee Break |
Theater |
4:45 – 6:00pm |
Shep Doeleman, MIT Haystack Observatory |
Theater |
Wednesday, November 12, 2014
Time |
Event |
Location |
9:00 – 9:25am |
Samir Mathur, Ohio State University |
Theater |
9:25 – 9:50am |
Gabriela Gonzalez, Louisiana State University |
Theater |
9:50 – 10:15am |
Xavier Siemens, University of Wisconsin-Milwaukee |
Theater |
10:15 – 10:45am |
Coffee Break |
Bistro – 1st Floor |
10:45 – 11:10am |
Jonelle Walsh, Texas A&M University |
Theater |
11:10 – 11:35am |
Stefan Gillessen, |
Theater |
11:35 – 12:00pm |
Jim Cordes, Cornell University |
Theater |
12:00 – 12:25pm |
Tim Johannsen, Perimeter Institute |
Theater |
12:25 – 1:00pm |
Dimitrios Psaltis, University of Arizona |
Theater |
1:00 – 2:00pm |
Lunch |
Bistro – 2nd Floor |
2:00 – 3:30pm |
Michael Kramer, Max Planck Institute for Radio Astronomy |
Theater |
3:45 – 4:10pm |
Dimitrios Psaltis, University of Arizona |
Theater |
4:10 – 6:00pm |
Avery Broderick, Perimeter Institute & University of Waterloo |
Theater |
6:30pm |
Conference Dinner |
Bistro – 2nd Floor |
Thursday, November 13, 2014
Time |
Event |
Location |
9:00 – 9:25am |
Remo Tilanus, Radboud University Nijmegen |
Theater |
9:25 – 9:50am |
Dan Marrone, University of Arizona |
Theater |
9:50 – 10:15am |
Array Site Reports |
Theater |
10:15 – 10:45am |
Coffee Break |
Bistro – 1st Floor |
10:45 – 12:00pm |
Array Site Reports cont. |
Theater |
12:00 – 12:25pm |
Gopal Narayanan, University of Massachusetts |
Theater |
12:25 – 12:40pm |
Conference Photo |
TBA |
12:40 – 2:30pm |
Lunch |
Bistro – 2nd Floor |
2:30 – 2:55pm |
Laura Vertatschitisch, |
Theater |
2:55 – 3:20pm |
Geoffrey Crew, MIT Haystack Observatory |
Theater |
3:20 – 3:45pm |
Ivan Marti-Vidal, Onsala Space Observatory |
Theater |
3:45 – 4:10pm |
Michael Hecht, MIT Haystack Observatory |
Theater |
4:10 – 4:40pm |
Coffee |
Bistro – 1st Floor |
4:40 – 6:00pm |
Shep Doeleman, MIT Haystack Observatory |
Theater |
7:00pm |
Movie Night |
Theater |
Friday, November 14, 2014
Time |
Event |
Location |
9:00 – 9:25am |
Jason Dexter, University of California, Berkeley |
Theater |
9:25 – 9:50am |
Andrew Chael, Harvard Smithsonian Center for Astrophysics Probing Dynamical Activity near the Event Horizon with the EHT |
Theater |
9:50 – 10:15am |
Mareki Honma, National Astronomical Observatory of Japan Super-resolution imaging with sparse modeling |
Theater |
10:15 – 10:45am |
Coffee |
Bistro – 1st Floor |
10:45 – 11:10am |
Michael Johnson, |
Theater |
11:10 – 11:35pm |
Vincent Fish, MIT Haystack Observatory |
Theater |
11:35 – 12:00pm |
Shep Doelman, MIT Haystack Observatory |
Theater |
12:00 – 12:25pm |
Jonathan Weintroub, |
Theater |
12:25 – 1:00pm |
EHT Organization |
Theater |
1:00 – 3:00pm |
Lunch |
Bistro – 2nd Floor |
Kazunori Akiyama, National Astronomical Observatory of Japan
Event-horizon-scale structure of M87 in the middle of the VHE enhancement in 2012
The radio galaxy M87 is an excellent laboratory for investigating the formation process of the relativistic jet and the production mechanism of high energy particles and photons in the vicinity of super-massive black holes. VLBI observations at 1.3 mm can address at least two issues concerning the fundamental nature of M87. The first is the event-horizon-scale structure of the jet launching region, and another one is the production mechanism of very high energy (VHE; > 100 GeV) photons at there. In this talk, I report on new 1.3 mm VLBI observations of M87 with the EHT during the VHE enhancement in 2012. These observations provide the first measurements of closure phase, imposing new constraints on accretion-disk/jet models for M87, and also the first constraints on the innermost structure of the relativistic jet on scales of a few Rs during VHE variability. I discuss results and their implications for jet/disk models and also VHE models for M87, as well as future prospects of EHT observations of M87.
Keiichi Asada, Academia Sinica Institute of Astronomy and Astrophysics
mm and sub-mm polarimetry of accretion flow towards M 87
Mass accretion rate on the SMBHs is one of the fundamental parameters used to investigate AGNs. Faraday Rotation Measure (RM) observations at mm/sub-mm wavelengths is one of the powerful methods to derive the mass accretion rate of hot accretion flows towards our galactic center, Sgr A* (e.g., Marrone et al. 2006). Based on this scheme, we conducted an SMA observation to apply this method to M 87, which is one of the primary target for our submm VLBI observations, in February 2013. We succeeded to derive an RM of (2.1 ± 1.8) × 10^5 rad m^-2, it gives the range of the mass accretion rate (M_dot) between 0 and 9.2 × 10^-4 M_sun yr^-1 at the distance of 21 rs from the SMBH. Our estimated M.is already two orders of magnitude smaller than the M_dot at the outer part of the accretion flow (~10^5 r_s) of 0.1 M_sun yr^-1 determined by X-ray observations (Di Matteo et al. 2003). This significant suppression of the M_dot at the inner region is expected with the radiatively inefficient accretion flow (RIAF) model. With future submm VLBI polarimetry towards jetted sources including M 87, we will derive the profile of accretion flow along the jet. It is very important itself for the study of the accretion process onto the SMBH, but also provide fundamental properties to derive BH parameters from the BH shadow imaging.
Geoff Bower, Academia Sinica Institute of Astronomy and Astrophysics
The Size and Morphology of Sgr A* at 7mm
Long wavelength measurements provide sensitive probes of the intrinsic structure of Sgr A* and of the scattering properties of the line-of-sight interstellar medium. At this wavelength, scattering dominates the apparent size of the source but careful closure amplitude techniques can provide highly accurate structural information. We present new results from the VLBA at 7mm wavelength that for the first time reveal two-dimensional intrinsic structure while also demonstrating the stability of the intrinsic size during periods of significant activity at NIR and X-ray wavelengths. These results also demonstrate the stability of the scattering medium over time. New observations of the Galactic Center pulsar PSR J1745-2900 show that the scattering properties of Sgr A* are spatially coherent over an angular scale of at least a few arc seconds. Analysis of the angular and temporal broadening data for the pulsar place the scattering medium at a distance of kiloparsecs away from the Galactic Center, resolving a significant mystery regarding the scattering medium.
Avery Broderick, Perimeter Institute & University of Waterloo
EHT Constraints on Jet Launching in M87
Because of the existence of a prominent jet, M87 provides an ideal source with which the EHT can critically test current jet launching paradigms. The EHT has already placed weak limits on the black hole spin based on generic arguments regarding limits on the image size. However, careful modeling of the jet structure can produce much more stringent constraints on both the black hole properties and the mechanisms responsible for the generation of the observed radio emission. I will describe how this modeling is performed, what the remaining chief uncertainties are and why we believe they can be controlled, and how existing EHT observations of M87 support models of electromagnetically launched jets powered by black hole spin.
Andrew Chael, Harvard-Smithsonian Center for Astrophysics
Probing Dynamical Activity near the Event Horizon with the EHT
Sgr A* regularly flares in the X-ray and near-IR on ~hour timescales, and the EHT has already detected interday variability in 1.3 mm emission on long and short baselines. The addition of highly sensitive long baselines in 2015 will allow for the resolution of time variable structure on sub-minute timescales. This opportunity to observe dynamical process on event horizon scales comes with the challenge of sparse visibility coverage, but several strategies can recover rich information from the limited samples. I will review sources of variability for the emission near supermassive black holes from minute to year timescales, and discuss the prospects of EHT observations for understanding event-horizon-scale dynamics.
Jim Cordes, Cornell University
Neutron Stars in the Galactic Center
I will discuss the prospects for finding additional radio pulsars in the Galactic center region and their utility for probing general relativity and other constituents in the region. This will include discussions of neutron star populations; radio wave scattering in and toward the Galactic center; issues and progress in discovering pulsars; and the precision to which discoverable pulsars can be timed.
Geoffrey Crew, MIT Haystack Observatory
EHT Correlation
Christiann Brinkerink, Radboud University Nijmegen
What closure phase measurements at 86 GHz can tell us about Sagittarius A*
Thomas Bronzwaer, Radboud University Nijmegen
Predicted VLBI Observables for SMBH's Based on GRMHD Simulations
Alejandro Cardenas-Avendano, Universidad Nacional de Colombia
Probing the Regular Nature of the Spacetime by Measuring the Shadow of a Black Hole
Andrew Chael, Harvard-Smithsonian Center for Astrophysics
Maximum Entropy Polarimetric Imaging
Laura Chajet, York University
AGNs: Line Width Distribution of MHD Disc Winds
Pierre Christian, Harvard Smithsonian Center for Astrophysics
complimentary observations to the EHT for understanding strong gravity
Riley Connors, University of Amsterdam
Jet Physics Across the Black Hole Mass Scale: Sgr A* and A0620-00
Roger Deane, University of Cape Town
Extreme Interferometry with MeqTrees: advanced interferometric simulation and analysis
Salome Dibi, Radboud University Nijmegen
The emission mechanisms from Sgr A*’s inner gravitational radii
Ciriaco Goddi, Radboud University Nijmegen
mm-VLBI in Europe
Jose L. Gomez, Instituto Astrofisica Andalucia-CSIC
Probing the magnetic field in the vicinity of supermassive AGN black holes with RadioAstron at 33 microarcseconds as angular resolution
Svetlana Jorstad, Boston University
Linear Polarization in the Jet of the Quasar 3C279 at near-EHT resolution
Motoki Kino, Korea Astronomy & Space Science Institute
Magnetic field strength at the jet base of M87
Michael Landry, LIGO Hanford Observatory
Advanced LIGO status
Alan Marscher, Boston University
Linear Polarization at 1 mm as a Probe of the "Core" of Blazar Jets
Gisela Ortiz, Universidad Nacional Autónoma de México
Testing a 3 mm VLBI system at the Large Millimeter Telescope: Observations of Sgr A*.
Hung-Pi Pu, Academia Sinica Institute of Astronomy & Astrophysics
Semi-analytical GRMHD jet model and its Synchrotron Image on Horizon Scale
Angelo Ricarte, Yale University
Probing Strong Gravity and Accretion Physics with the Event Horizon Telescope
Frank Roelofs, Radboud University Nijmegen
imaging Sgr A* through time-variability
Eduard Ros, Max Planck Institute for Radio Astronomy
Jet formation region of NGC 1052 with mm-VLBI
Fumie Tazaki, National Astronomical Observatory of Japan
super-resolution images of M87 with compressed sensing
Discussion 2
Optimized Image Reconstruction: Insights from Optical Interferometry
The radio community pioneered the use of closure phases to allow interferometric imaging even when fringe phases are compromised by atmospheric turbulence or unstable reference clocks. Eventually, better receivers and observing methods allowed phase referencing to provide direct measures of complex visibilities and eased the uncertainties using Fourier inversions required for imaging.
Detection and Implications of Horizon-Scale Polarization in Sgr A*
The Event Horizon Telescope has measured compact emission in Sgr A* and M87 at resolutions comparable to their event horizons. Polarimetry with the EHT enables a powerful extension of this work, mapping magnetic field structures via the highly polarized synchrotron emission that is thought to dominate the compact emission. Sgr A* provides an especially attractive target for linear polarization studies with the EHT because it is unpolarized at the longer wavelengths where facility instruments are available.
Detection and Variability of Closure Phases in Sgr A*
Discussion 1
Particle Acceleration and Non-thermal Emission in Radiatively Inefficient Accretion Flows
I summarize several physical processes that can produce efficient particle acceleration in radiatively inefficient accretion flows. I then describe the implications for non-thermal emission and EHT observations of Sgr A*.
The Size and Morphology of Sgr A* at 7mm
Long wavelength measurements provide sensitive probes of the intrinsic structure of Sgr A* and of the scattering properties of the line-of-sight interstellar medium. At this wavelength, scattering dominates the apparent size of the source but careful closure amplitude techniques can provide highly accurate structural information. We present new results from the VLBA at 7mm wavelength that for the first time reveal two-dimensional intrinsic structure while also demonstrating the stability of the intrinsic size during periods of significant activity at NIR and X-ray wavelengths.
Constraints on Sgr A*s accretion geometry and plasma characteristics from the 3Msec Chandra (+ multiwavelength) campaign
Sgr A* is one of the few black holes whose capture radius is just resolvable with the
Stellar Orbits at the Galactic Center
Over the last 20 years, advances in high angular resolution imaging technology has enabled the motions of individual stars to be tracked at the Galactic Center.
Polarized emission from Black Hole Accretion Disks and Jets
We discuss how polarized emission can place constraints on the properties of accretion flows and jets in the strong gravity regime for systems like SgrA* and M87 being observed by the Event Horizon Telescope.
Pages
Scientific Organizers:
- Avery Broderick, Perimeter Institute & University of Waterloo
- Shep Doeleman, MIT Haystack Observatory
- Luis Lehner, Perimeter Institute
- John Moffat, Perimeter Institute
- Dimitrios Psaltis, University of Arizona
- Jonathan Weintroub, Harvard Smithsonian Center for Astrophysics
Scientific Organizing Committee:
- Heino Falcke, Radbout University Nimegen
- Gabriela Gonzalez, Louisiana State University
- Paul Ho, Academia Sinica Institute of Astronomy and Astrophysics
- Mareki Honma, National Astronomical Observatory of Japan
- Michael Kramer, Max Planck Institute for Radio Astronomy
- Sera Markoff, University of Amsterdam
- Dan Marrone, University of Arizona
- John Wardle, Brandeis University
- Anton Zensus, Max Planck Institute for Radio Astronomy
- Lucy Ziurys, University of Arizona