A team of American and
Dutch physicists has discovered the
earliest and
most distant active galactic nucleus.
The result has important implications for the
early history of the
universe.
Astronomers currently believe that super-massive black holes form at the
centre of galaxies.
However,
in the
early universe there would not have been enough time for such black holes to form according to existing models of galaxy formation.
The new results suggest instead that primordial black holes - formed at the
beginning of the
universe - may have merged together to form a proto-galactic nucleus.
These proto-nuclei would have gradually attracted enough gas and
dust to form the
early galaxies.
TN J0924-2201 – at 9 percent the
age of the
universe and
- is a prime candidate to confirm this theory (The Astrophysical Journal
June 20).
Wil van Breugel from the
Lawrence Livermore Laboratory and
colleagues from the
University of California,
Berkeley and Leiden Observatory in the Netherlands found their
galactic nucleus by looking for radio sources that generate strong radio waves over a
narrow band from a single power source. They looked for optical candidates of these
sources at near infrared wavelengths using the Keck II telescope. This allowed them to
measure the redshift of the objects. The galaxy at TN J0924-2201 was measured at a
redshift of 5.19 - further than any known quasar source. This overturns the idea that
quasars are the most distant radio sources in the universe.
Earlier this year the Hubble Space Telescope pinpointed the most distant galaxy at
ultraviolet wavelengths at a redshift of 6.68 - 5% the present age of the universe.
