Messier 87 (M87) is a giant elliptical galaxy in the Virgo Cluster of galaxies, roughly 50 million light years from Earth. The HST has peered into its center to seek evidence for the presence of a supermassive black hole.
This near-infrared image of the center of M87 shows a jet of ionized gas or plasma extending toward the right from an extremely bright spot. The bright spot is unresolved, meaning that it must be less than about 6.5 light years in diameter. It does not appear to be starlight, and may be produced by radiation from highspeed electrons moving through a magnetic field. Such electrons also produce powerful radio emission. M87 is the brightest radio source in the constellation Virgo, known to radio astronomers as Virgo A.
The jet, extending more than 5,000 light years from the center of M87 in the HST images, is believed to consist of material expelled from the vicinity of a supermassive black hole in the center of the galaxy. The general background of starlight in M87 increases systematically toward the center in a way that is consistent with mathematical predictions, on the assumption that the concentration of stars is under the gravitational influence of a central black hole with 3.6 billion times the mass of the Sun. The density of stars near the center appears to be over 1,000 times greater than in the vicinity of the Earth, and could be much larger.
Also visible in the image are a number of star-like points of lights scattered about the center. These are globular star clusters within M87, each composed of 100 thousand to a million stars.
Camera: WF/PC-1
Technical Information: Near infrared image
at wavelength of 890 nm.
Credit: T. Lauer (NOAO), S. Faber (UCSC),
and NASA
