skip to main content

SciTech ConnectSciTech Connect

Title: Imaging the supermassive black hole shadow and jet base of M87 with the event horizon telescope

The Event Horizon Telescope (EHT) is a project to assemble a Very Long Baseline Interferometry (VLBI) network of millimeter wavelength dishes that can resolve strong field general relativistic signatures near a supermassive black hole. As planned, the EHT will include enough dishes to enable imaging of the predicted black hole 'shadow', a feature caused by severe light bending at the black hole boundary. The center of M87, a giant elliptical galaxy, presents one of the most interesting EHT targets as it exhibits a relativistic jet, offering the additional possibility of studying jet genesis on Schwarzschild radius scales. Fully relativistic models of the M87 jet that fit all existing observational constraints now allow horizon-scale images to be generated. We perform realistic VLBI simulations of M87 model images to examine the detectability of the black shadow with the EHT, focusing on a sequence of model images with a changing jet mass load radius. When the jet is launched close to the black hole, the shadow is clearly visible both at 230 and 345 GHz. The EHT array with a resolution of 20-30 μas resolution (∼2-4 Schwarzschild radii) is able to image this feature independent of any theoretical models and we show thatmore » imaging methods used to process data from optical interferometers are applicable and effective for EHT data sets. We demonstrate that the EHT is also capable of tracing real-time structural changes on a few Schwarzschild radii scales, such as those implicated by very high-energy flaring activity of M87. While inclusion of ALMA in the EHT is critical for shadow imaging, the array is generally robust against loss of a station.« less
Authors:
; ; ;  [1] ;  [2] ;  [3] ;  [4]
  1. Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States)
  2. Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5 (Canada)
  3. Department of Physics and Astronomy, Georgia State University, 25 Park Place NE, Atlanta, GA 30303 (United States)
  4. Department of Astronomy, University of Michigan, 918 Dennison Building, Ann Arbor, MI 48109-1090 (United States)
Publication Date:
OSTI Identifier:
22356615
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 788; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; FLARING; GALAXIES; INCLUSIONS; INTERFEROMETERS; INTERFEROMETRY; MASS; RELATIVISTIC RANGE; RESOLUTION; SCHWARZSCHILD RADIUS; SIMULATION; TELESCOPES; VISIBLE RADIATION; WAVELENGTHS