Bursting
With Stars
and Black
Holes
A
growing
black
hole,
called a
quasar,
can be
seen at
the center
of a
faraway
galaxy in
this
artist's
concept.
Using
NASA's
Spitzer
and
Chandra
Space
Telescopes,
astronomers
discovered
swarms of
similar
quasars
hiding in
dusty
galaxies
in the
distant
universe.
The
new-found
quasars
belong to
a
long-lost
population
that had
been
theorized
to be
buried
inside
dusty,
distant
galaxies,
but were
never
actually
seen.
While some
quasars
are easy
to detect
because
they are
oriented
in such a
way that
their
X-rays
point
toward
Earth,
others are
oriented
with their
surrounding
doughnut-clouds
blocking
the X-rays
from our
point of
view. In
addition,
dust and
gas in the
galaxy
itself can
block the
X-rays.
Astronomers
had
observed
the most
energetic
of this
dusty, or
obscured,
bunch
before,
but the
"masses,"
or more
typical
members of
the
population,
remained
missing.
Using data
from
Spitzer
and
Chandra,
scientists
uncovered
many of
these lost
quasars in
the
bellies of
massive
galaxies
between 9
and 11
billion
light-years
away.
Because
the
galaxies
were also
busy
making
stars, the
scientists
now
believe
most
massive
galaxies
spent
their
adolescence
building
stars and
black
holes
simultaneously.
|
