快猫短视频

BLACK hole hunters are on a roll, having found eight more galaxies that have
supermassive black holes at their centres, bringing the total of these galaxies
to 33. 鈥淲e鈥檙e moving from the study of individual objects to the study of a
population,鈥� says Richard Green, director of Kitt Peak National Observatory in
Arizona.

And according to John Kormendy of the University of Texas in Austin, the new
results, obtained with a sensitive spectrograph on board the Hubble Space
Telescope, reveal that a giant black hole is not born in isolation and then
gathers a galaxy around itself. Instead, it must grow with its surrounding
stars.

In an earlier study, Kormendy and Karl Gebhardt of the Lick Observatory in
California found a surprising relation between the mass of a galaxy鈥檚 central
bulge and the mass of the black hole at its core. Whatever the mass of the
bulge, the black hole always weighed 0.2 per cent of it.

Now, Kormendy and Gebhardt have found an even closer correlation between the
mass of the giant black hole and the distribution of the velocities of the stars
in the galaxy. 鈥淭his means that the same process that made the bulge grow, also
made the black hole grow,鈥� says Kormendy.

If Kormendy and Gebhardt鈥檚 new result holds up, every galaxy bulge probably
harbours a black hole. 鈥淭hese are interesting results,鈥� says Roeland van der
Marel of the Space Telescope Science Institute in Baltimore, Maryland.