Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre

2003/10/01 by R. Genzel, R. Schoedel, R. Schödel +9 · 9 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Galaxy #Infrared #Intermediate-mass black hole #Physics #Pulsars and Gravitational Waves Research #Supermassive black hole #astro-ph

paper · pdf · doi:10.1038/nature02065

published as Nature 425 (2003) 934-937 · 5 pages, 3 figures to appear in the Oct 30 issue of Nature

openalex publication_date 2003/10/01 · arxiv created 2003/10/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Recent measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a 3.6-million-solar-mass black hole. Sgr A* is remarkably faint in all wavebands other than the radio region, however, which challenges current theories of matter accretion and radiation surrounding black holes. The black hole's rotation rate is not known, and therefore neither is the structure of space-time around it.Here we report high-resolution infrared observations of Sgr A* that reveal 'quiescent' emission and several flares. The infrared emission originates from within a few milliarcseconds of the black hole, and traces very energetic electrons or moderately hot gas within the innermost accretion region. Two flares exhibit a 17-minute quasi-periodic variability. If the periodicity arises from relativistic modulation of orbiting gas, the emission must come from just outside the event horizon, and the black hole must be rotating at about half of the maximum possible rate.

Citations

• Structure of Sagittarius A* at 86 GH[CLC]z[/CLC] using VLBI Closure Quantities
• The First Measurement of Spectral Lines in a Short-Period Star Bound to the Galaxy’s Central Black Hole: A Paradox of Youth
• Proper Motion of the Compact, Nonthermal Radio Source in the Galactic Center, Sagittarius A*
• New Constraints on the Nature of Radio Emission in Sagittarius A*
• Measuring the Black Hole Spin in Sagittarius A*
• Near‐Infrared Microlensing of Stars by the Supermassive Black Hole in the Galactic Center
• Magnetically Driven Accretion Flows in the Kerr Metric. I. Models and Overall Structure
• The Nature of the 10 kilosecond X-ray flare in Sgr A*

Cited by

• A forest of gravitational waves in our Galactic Centre
• Gravitational lensing and frame dragging of light in the Kerr–Newman and the Kerr–Newman (anti) de Sitter black hole spacetimes
• The black hole at the Galactic Center: Observations and models
• Multiwavelength Light Curves of Two Remarkable Sagittarius A* Flares
• Spin and mass of the nearest supermassive black hole
• MEASURING THE SPIN OF THE PRIMARY BLACK HOLE IN OJ287
• A 600 Minute Near-Infrared Light Curve of Sagittarius A*
• Detection of Sub-TeV Gamma Rays from the Galactic Center Direction by CANGAROO-II
• Silhouettes of invisible black holes