Scientists say 'hallelujah' in jubilation, having captured the glimmer of what is known as the farthest and the oldest galaxy in the universe
THE farthest hazy horizons of the universe seem to emerge clear, as
astronomers working with the Keck
telescope in Hawaii have recently
claimed to have observed the most distant galaxy (and the oldest) known to
humankind as yet. Embedded in the
constellation Virgo some 14 billion fight
years away, this galaxy is believed to
have 'been formed only a billion years
after the 'Big Bang' - when the universe is supposed to have been born.
"Looking at the very distant parts
of the universe is essentially looking
back in time, because, an image one
billion light years away has taken a
billion years to reach the earth," said
Thomas Barlow, one of -the four
astronomers at the California Institute
of Technology (Caltech), credited with
the discovery.
In astronomy, the distance of the
observed objects are gauged by the so
called 'red shift' in the corresponding
spectra (red corresponds to the highest
wavelength in the visible spectral range)
which might increase or decrease
with the movement, of -the objects.
When the source of electromagnetic
radiation is receding from the observer,
a wavelength longer than the original
signal is observed; and the further the
galaxy is from the earth, the faster,
according to Hubble's Law, it is moving
away from us.
I Thus, light from an object at-a very
high red shift implies that it is located
very far out in the space. The red shift of
this newly discovered galaxy was measured at 4.38. Scientists Wallace Sargent,
Li-min Lu, Donna Womble and
Thomas Barlow reported their findings
in the current issue of the Astrophysical
Journal Letters. Lu, a Hubble Fellow
at the Caltech, said that the discovery
was made while observing a distant
quasi-stellar object - the source of
brightest light 'among all celestial
objects. When they examined the quaser
spectrum, the astronomers noted
certain dark lines in it, which indicated
that 'something' was absorbing certain
wavelengths of the light originating
from the quaser.
The analysis of this 'absorption
spectrum' of the quaser led to the
calculation of the red shift of the 'something', that turned out to be the yet
unnamed galaxy.-The apparent distance
of this galaxy is about 200 million light
years.
An intertesting fallout of this observation is the detection of tiny quantities
of-carbon, oxygen, silicon, aluminium
and iron in the spectrum of the new
galaxy. Cosmologists bel -ieve that almost
all the carbon found in the universe was
formed in the stars. Jeremiah P Ostriker,
an astrophysicist from Princeton
University, had predicted years ago, that
cosmic instabilities after the Big Bang
could have triggered star formation
before the first galaxies formed. David
Tytler, an astrophysicist at the
University of California at San Diego,
however, proposes that the carbon was
created in stars which were located in
the galaxies, which themselves were in
an infantile stage.
Therefore, based on the assumption
that the Big Bang occured a billion years
before all this happened, the discovery
of carbon and iron pushes back the
birth date of the new galixy to almost
about 14 billion years. Astronomers
hope'that studies on this galaxy would
provide strong insights into the
universe and the formative period
of several galaxies, including the
Milky Way - home to our very own
mother Earth.
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