Birth of black hole kills the radio star

Date:

Share post:

Astronomers led by a Curtin University researcher have discovered a new population of exploding stars that “switch off” their radio transmissions before collapsing into a Black Hole.

Birth of black hole kills the radio star
If matter and antimatter repel each other, the quick conversion of one into the other inside
a supermassive black hole may look like a Big Bang [Credit: NASA]

These exploding stars use all of their energy to emit one last strong beam of highly energetic radiation — known as a gamma-ray burst — before they die.

Up until now, it was thought all gamma-ray bursts were followed by a radio afterglow — a premise that a team of Australian astronomers of the Centre for All-sky Astrophysics (CAASTRO) at Curtin University and the University of Sydney originally set out to prove correct.

“But we were wrong. After studying an ultra-sensitive image of gamma-ray bursts with no afterglow, we can now say the theory was incorrect and our telescopes have not failed us,” lead researcher and Curtin research fellow Dr Paul Hancock said.

The technique used to create the ultra-sensitive image was recently published in The Astrophysical Journal.

It allowed for the stacking of 200 separate observations on top of each other to re-create the image of a gamma-ray burst in much better quality — yet, no trace of a radio afterglow was found.

“In our research paper we argue that there must be two distinct types of gamma-ray burst, likely linked to differences in the magnetic field of the exploding star,” Dr Hancock said.

“Gamma-ray bursts are thought to mark the birth of a Black Hole or Neutron Star — both of which have super-dense cores. But Neutron Stars have such strong magnetic fields (a million times stronger than those of Black Holes) that producing gamma-rays are more difficult.

“We think that those stars that collapse to form a Neutron Star have energy left over to produce the radio afterglow whereas those that become Black Holes put all their energy into one final powerful gamma-ray flash.”

New work is underway to test the team’s theory and to see if there are other subtle ways in which the two types of bursts differ.

“We now have to take a whole new look at gamma-ray bursts — so far this work has shown that being wrong is sometimes more interesting than being right,” Dr Hancock said.

Telescope facilities such as the Australia Telescope Compact Array in northern New South Wales and the Karl Jansky Very Large Array in the US both have observing programs to search for gamma-ray burst afterglows and have been recently upgraded to increase their sensitivity.

Source: Curtin University [December 20, 2013]

ADVERTISEMENT

spot_img

Related articles

2,000 year old clay doll dug up at Osaka ruins site

A moon-faced clay doll from the mid-Yayoi Pottery Culture period (300 B.C.-A.D. 300) has been unearthed in near...

Tomb belonging to Moche ruler unearthed in northern Peru

Archaeologists working at the Huaca de la Luna have unearthed a previously unknown tomb belonging to a Moche...

Microlensing study suggests most common outer planets likely Neptune-mass

A new statistical study of planets found by a technique called gravitational microlensing suggests that Neptune-mass worlds are...

2,000-year-old warrior’s grave unearthed at golf course

 A warriot grave dating back 2,000 years has been discovered under the site of a new golf clubhouse. Spear...

Bid to save Pictish cave art from coastal erosion

Archaeologists are hoping to save ancient cave drawings from coastal erosion. Since the 5th century humans have been...

Academic recognised for illicit antique fight

A Swansea academic has won an international award for his work in tackling the illicit trade in antiques....

More on Finds shed light on ancient earthquake in Israel

Silent evidence of a large earthquake in 363 CE -- the skeleton of a woman with a dove-shaped...

Parthian era graves discovered in Iran

The second season of field research on an ancient settlement and cemetery in Amlash, in Iran's Gilan province,...