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

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.”


South Korean TV ‘reunites’ mother with dead daughter in virtual reality show

This undated handout photo provided on February 14, 2020 by South Korea's Munhwa Broadcasting Corporation (MBC) in Seoul shows a scene of a documentary "I met you" where a mother meets her dead daughter through virtual reality. (AFP)
Updated 18 February 2020

South Korean TV ‘reunites’ mother with dead daughter in virtual reality show

  • The footage began with the girl — who died of leukaemia in 2016 — emerging from behind a pile of wood in a park, as if playing hide-and-seek
  • “I have missed you Na-yeon,” she told the computer-generated six-year-old, her hands moving to stroke her hair

SEOUL: A tearful reunion between a mother and her dead daughter via advanced virtual reality for a South Korean television has become an online hit, triggering fierce debate about voyeurism and exploitation.
The footage began with the girl — who died of leukaemia in 2016 — emerging from behind a pile of wood in a park, as if playing hide-and-seek.
“Mum, where have you been?” she asks. “I’ve missed you a lot. Have you missed me?“
Tears streaming down her face, Jang Ji-sung reached out toward her, wracked with emotion.
“I have missed you Na-yeon,” she told the computer-generated six-year-old, her hands moving to stroke her hair.
But in the real world, Jang was standing in front of a studio green screen, wearing a virtual reality headset and touch-sensitive gloves, her daughter’s ashes in a locket around her neck.
At times the camera cut to Jang’s watching husband and their three surviving children, wiping away tears of their own.
A nine-minute clip of the Munhwa Broadcasting Corporation (MBC) documentary “I met you” has been watched more than 13 million times in a week on Youtube.
Many viewers offered Jang their sympathy and support for the concept.
“My mother unexpectedly passed away two years ago and I wish I could meet her through virtual reality,” said one.
But media columnist Park Sang-hyun said the documentary amounted to exploitation of personal pain.
“It’s understandable a grief-stricken mother would wish to meet her late daughter. I would do the same,” he told AFP.
“The problem lies in that the broadcaster has taken advantage of a vulnerable mother who lost a child for sake of the viewer ratings.”
“If the mother had been counselled before the filming,” he added, “I wonder what kind of a psychiatrist would approve this.”

It took eight months of filming and programming to create the virtual Na-yeon, but the makers of the documentary insisted the broadcast was intended to “console the family” rather than promote virtual reality in ultra-wired South Korea.
The technology presented a “new way to keep loved ones in memory,” one of the producers told reporters.
Jang herself — who has her daughter’s name and date of birth tattooed on her arm in memory — hoped the program could “console” others who had lost loved ones.
“Even though it was a very brief... I was really happy in the moment,” she wrote on her blog — which she has since turned private.
During the broadcast the two sat at a table to celebrate Na-yeon’s missing birthdays, singing “happy birthday” together.
Before blowing out the candles, Na-yeon made a birthday wish: “I want my mother to stop crying.”