Big Bang afterglow reveals dark energy's repulsion
13:22 22 July 03

Observation of the cosmic radiation emitted just after the Big Bang has
revealed further evidence for the Universe's mysterious and elusive dark
energy.

Astronomers from the Sloan Digital Sky Survey, the University of
Pittsburgh and Carnegie Mellon University in the US studied the cosmic
microwave background (CMB) radiation, the faint but pervasive afterglow
of our Universe's explosive beginnings.

The team analysed changes in the energy of CMB photons caused by the
gravity of massive concentrations of galaxies. As photons pass through
these galactic masses, gravitational potential causes them to gain and
then lose energy. Once the photon has passed through, the energy changes
should have cancelled out.

But the CMB photons studied had slightly higher energy levels on leaving
the galaxy concentrations. This change can only be explained by invoking
the influence of dark energy in the expansion of these massive galactic
structures.

"This is extremely exciting," says Ryan Scranton, of the University of
Pittsburgh. "We spent a lot of time testing the data against
contamination from our galaxy or other sources. Having the results come
out as strongly as they did was extremely satisfying."

Read the rest at NewScientist
http://www.newscientist.com/news/news.jsp?id=ns99993963

Trace gas dates Universe's first stars
18:00 23 July 03

A giant cloud containing carbon monoxide has been spied in the most
distant known galaxy in the Universe.

Light from the galaxy was emitted when the Universe was just a sixteenth
of its current age. Astronomers say the traces of gas prove that star
formation got started astonishingly quickly in the young Universe.

"The presence of carbon monoxide is very interesting because carbon and
oxygen first need to form in stars of some sort, then be expelled by
explosions," says team leader Fabian Walter of the National Radio
Astronomy Observatory in Socorro, New Mexico.

The most distant known galaxy in the Universe is a "quasar" called
J1148+5251, which contains a black hole at least a billion times heavier
than the Sun. It shines so brightly because material being dragged
inwards by the hole's powerful gravitational field gets heated to
enormous temperatures.

http://www.newscientist.com/news/news.jsp?id=ns99993974

--
Kind Regards,
Robert Karl Stonjek.