Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre

2008/09/01 by Sheperd Doeleman, Sheperd S. Doeleman, Jonathan Weintroub +47 · 11 citations
Physics and Astronomy · #Accretion (finance) #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Black hole (networking) #Event (particle physics) #Event horizon #Experimental and Theoretical Physics Studies #Galactic Center #Galaxy #Intermediate-mass black hole #Milky Way #Physics #Sagittarius #Sagittarius A* #Stellar black hole #Supermassive black hole #Very-long-baseline interferometry #astro-ph

paper · pdf · doi:10.1038/nature07245

published as Nature, vol 455, p 78, 2008 · 12 pages including 2 figures

openalex publication_date 2008/09/01 · arxiv created 2008/09/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

The cores of most galaxies are thought to harbour supermassive black holes, which power galactic nuclei by converting the gravitational energy of accreting matter into radiation (ref 1). Sagittarius A*, the compact source of radio, infrared and X-ray emission at the centre of the Milky Way, is the closest example of this phenomenon, with an estimated black hole mass that is 4 million times that of the Sun (refs. 2,3). A long-standing astronomical goal is to resolve structures in the innermost accretion flow surrounding Sgr A* where strong gravitational fields will distort the appearance of radiation emitted near the black hole. Radio observations at wavelengths of 3.5 mm and 7 mm have detected intrinsic structure in Sgr A*, but the spatial resolution of observations at these wavelengths is limited by interstellar scattering (refs. 4-7). Here we report observations at a wavelength of 1.3 mm that set a size of 37 (+16, -10; 3-sigma) microarcseconds on the intrinsic diameter of Sgr A*. This is less than the expected apparent size of the event horizon of the presumed black hole, suggesting that the bulk of SgrA* emission may not be not centred on the black hole, but arises in the surrounding accretion flow.

Citations

• Structure of Sagittarius A* at 86 GH[CLC]z[/CLC] using VLBI Closure Quantities
• The Proper Motion of Sagittarius A*. II. The Mass of Sagittarius A*
• Detection of the Intrinsic Size of Sagittarius A* Through Closure Amplitude Imaging
• A size of ∼1 au for the radio source Sgr A* at the centre of the Milky Way
• Proper Motion of the Compact, Nonthermal Radio Source in the Galactic Center, Sagittarius A*
• Dynamical Constraints on Alternatives to Supermassive Black Holes in Galactic Nuclei
• Viewing the Shadow of the Black Hole at the Galactic Center
• On the Nature of the Compact Dark Mass at the Galactic Center

Cited by

• Evaluation of New Submillimeter VLBI Sites for the Event Horizon Telescope
• Electromagnetic emissions from near-horizon region of an extreme Kerr-Taub-NUT black hole
• THE PROPER MOTION OF THE GALACTIC CENTER PULSAR RELATIVE TO SAGITTARIUS A*
• USING MILLIMETER VLBI TO CONSTRAIN RIAF MODELS OF SAGITTARIUS A*
• Polarimetric Properties of Event Horizon Telescope Targets from ALMA
• Silhouettes of invisible black holes
• Jets at lowest mass accretion rates
• Light escape cones in local reference frames of Kerr–de Sitter black hole spacetimes and related black hole shadows
• GRay2: A General Purpose Geodesic Integrator for Kerr Spacetimes
• Circular orbits and accretion disk around a deformed-Schwarzschild black hole in loop quantum gravity
• The ALMA Phasing System: A Beamforming Capability for Ultra-high-resolution Science at (Sub)Millimeter Wavelengths