New Universe map unearths 300,000 more galaxies

A new project found 300,000 previously unseen light sources using a telescope that can detect light sources optical instruments cannot see. Above, galaxy MACS1149-JD1 located 13.28 billion light-years away as seen with the NASA/ESA Hubble Space Telescope in May 2018. (AFP)
Updated 19 February 2019
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New Universe map unearths 300,000 more galaxies

  • Discovery literally sheds new light on some of the Universe’s deepest secrets
  • More than 200 astronomers from 18 countries were involved in the study

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.”


NASA scraps all-women spacewalk for lack of well-fitting suits

In this file photo taken on March 14, 2019 NASA astronauts Christina Hammock Koch and Nick Hague, members of the International Space Station (ISS) expedition 59/60, react shortly before the launch onboard the Soyuz MS-12 spacecraft from the Russian-leased Baikonur cosmodrome in Kazakhstan. (AFP)
Updated 26 March 2019
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NASA scraps all-women spacewalk for lack of well-fitting suits

  • The spacesuits aboard the ISS are in fact assemblies of several parts put together as best adapted to each astronaut’s body, explained Brandi Dean, spokeswoman of the Johnson Space Center in Houston

WASHINGTON: The US space agency NASA scrapped Monday a planned historic spacewalk by two women astronauts, citing a lack of available spacesuits that would fit them at the International Space Station.
Christina Koch will now perform tasks in space Friday with fellow American Nick Hague — instead of Anne McClain as originally planned.
Had Koch and McClain done their spacewalk together, it would have been the first ever by two women astronauts.
Until now, male-only or mixed male-female teams had conducted spacewalk since the space station was assembled in 1998 — 214 spacewalks until now.
McClain worked outside the station last week — with Hague — when she realized that a “medium“-sized upper half of her spacesuit fit her better.
“Because only one medium-size torso can be made ready by Friday, March 29, Koch will wear it,” NASA explained.
The spacesuits aboard the ISS are in fact assemblies of several parts put together as best adapted to each astronaut’s body, explained Brandi Dean, spokeswoman of the Johnson Space Center in Houston, Texas where American astronauts are based.
She said two upper parts in each of the three available spacesuit sizes are currently held at the ISS: medium, large and extra large.
“We do our best to anticipate the spacesuit sizes that each astronaut will need, based on the spacesuit size they wore in training on the ground, and in some cases astronauts train in multiple sizes,” she said in explaining the problem that hampered Friday’s planned spacewalk.
“However, individuals’ sizing needs may change when they are on orbit, in response to the changes living in microgravity can bring about in a body.
“In addition, no one training environment can fully simulate performing a spacewalk in microgravity, and an individual may find that their sizing preferences change in space.”