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

Article

关键词: SAGITTARIUS-A-ASTERISK;    X-RAY;    INTRINSIC SIZE;    PROPER MOTION;    RADIO-SOURCE;    MILKY-WAY;    86 GHZ;    VLBI;    EMISSION;    COMPACT;   

DOI  :  10.1038/nature07245

来源: SCIE

【 摘 要 】

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(1). Sagittarius A* ( Sgr 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 4,000,000 times that of the Sun(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(4-7). Here we report observations at a wavelength of 1.3 mm that set a size of 37(-10)(+16) 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 Sgr A* emission may not be centred on the black hole, but arises in the surrounding accretion flow.

【 授权许可】

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