supernova

The waves could have been
made by a supernova.

NASA Goddard
Space Flight Center / Flickr

Some mysterious radio waves from space have left astronomers
scratching their heads for years. The cosmic waves are called
“fast radio bursts” (FRBs) and were
first discovered about a decade ago. 

However, it wasn’t clear where the bursts were coming from, or
what was making them. It was assumed that they originated
somewhere within the Milky Way or a nearby galaxy.

Thanks to new information published in the journal Nature, researchers
from Cornell University, McGill University, and other
international institutions found that the FRBs were coming all
the way from across the universe, more than 3 billion light-years
away. 

The first FRBs were actually detected at the Parkes Radio
Telescope in New South Wales, Australia in 2007 by a US undergraduate student who was looking
at archived data from the Parkes radio
dish. In November 2012, astronomers from Cornell
discovered a new FRB which they named, creatively, FRB
121102. Four years later, researchers estimated that that
FRB was coming from somewhere around about 6 billion light years away.

For the most recent study, the National Radio Astronomy
Observatory’s Karl G Jansky Very Large Array telescope in New
Mexico provided the resolution needed to pinpoint the FRB’s
precise location. It turns out that FRB 121102 originates from
the pentagon-shaped constellation called Auriga. 

“The host galaxy for this FRB appears to be a very humble and
unassuming dwarf galaxy, which is less than 1 percent of the mass
or our Milky Way galaxy,” said Dr Shriharsh Tendulkar,
an expert in neutron stars at McGill University and one of the
authors of the study, in a statement. “That’s surprising. One would
generally expect most FRBs to come from large galaxies which have
the largest numbers of stars and neutron stars — remnants of
massive stars.”

He added that the dwarf galaxy has fever stars than they would
expect, but it’s also forming them at a fast rate. This
could suggest that FRBs are linked to the creation of young
neutron stars, he said.

More radio emissions were detected from the same region,
which could be a result of two other extreme events that often
occur in dwarf galaxies: long duration gamma-ray bursts and
superluminous supernovae, which is a hugely energetic star
explosion. 

However, although the location of the FRBs has been found, what
is really creating them remains a mystery. 

“We think it may be a magnetar — a newborn neutron star with a
huge magnetic field, inside a supernova remnant or a pulsar wind
nebula — somehow producing these prodigious pulses,” said lead
author Shami Chatterjee, a senior research associate in astronomy
at Cornell University,
in a statement. “Or, it may be an active galactic nucleus of
a dwarf galaxy… Or it may be a combination of those two ideas —
explaining why what we’re seeing may be somewhat rare.”