New Universe map unearths 300,000 more galaxies

Author: 
AFP
ID: 
1550563500773859500
Tue, 2019-02-19 08:00

PARIS: The known Universe just got a lot bigger.
A new map of the night sky published Tuesday charts hundreds of
thousands of previously unknown galaxies discovered using a
telescope that can detect light sources optical instruments cannot
see.
The international team behind the unprecedented space survey said
their discovery literally shed new light on some of the
Universe’s deepest secrets, including the physics of black holes
and how clusters of galaxies evolve.
“This is a new window on the universe,” Cyril Tasse, an
astronomer at the Paris Observatory who was involved in the
project, said.
“When we saw the first images we were like: ‘What is this?!’
It didn’t look anything at all like what we are used to
seeing.”
More than 200 astronomers from 18 countries were involved in the
study, which used radio astronomy to look at a segment of sky over
the northern hemisphere, and found 300,000 previously unseen light
sources thought to be distant galaxies.
Radio astronomy allows scientists to detect radiation produced when
massive celestial objects interact.
The team used the Low Frequency Array (LOFAR) telescope in the
Netherlands to pick up traces — or “jets” — of ancient
radiation produced when galaxies merge. These jets, previously
undetected, can extend over millions of light years.
“With radio observations we can detect radiation from the tenuous
medium that exists between galaxies,” said Amanda Wilber, of the
University of Hamburg.
“LOFAR allows us to detect many more of these sources and
understand what is powering them.”
The discovery of the new light sources may also help scientists
better understand the behavior of one of space’s most enigmatic
phenomena.
Black holes — which have a gravitational pull so strong that no
matter can escape them — emit radiation when they engulf other
high-mass objects such as stars and gas clouds.
Tasse said the new observation technique would allow astronomers to
compare black holes over time to see how they form and develop.
“If you look at an active black hole, the jets (of radiation)
disappear after millions of years, and you won’t see them at a
higher frequency (of light),” he said.
“But at a lower frequency they continue to emit these jets for
hundreds of millions of years, so we can see far older
electrons.”
The Hubble telescope has produced images that lead scientists to
believe there are more than 100 billion galaxies in the Universe,
although many are too old and distant to be observed using
traditional detection techniques.
The map created by the LOFAR observations, part of which was
published in the journal Astronomy & Astrophysics, contains
data equivalent to ten million DVDs yet charts just two percent of
the sky.
The LOFAR telescope is made up of a Europe-wide network of radio
antenna across seven countries, forming the equivalent of a
1,300-kilometer diameter satellite dish.
The team plans to create high-resolution images of the entire
northern sky, which they say will reveal as many as 15 million
as-yet undetected radio sources.
“The oldest objects in the Universe are around 11-12 billion
light years old,” said Tasse. “So we are going to see lots more
of these objects.”

Tags: 

New 3-D map of Milky Way will ‘revolutionize
astronomy’Astronomers report first image of baby planet being
formed
Source: *FS – All – Science News Net
New Universe map unearths 300,000 more galaxies