Astronomers have picked up a mysterious radio signal that could have come from a neutron star, black hole or even an alien civilization.
For the first time, astronomers have been able to pick up and observe a fast radio burst in real time as it moves through space. Though little is know about these radio bursts, which are short and sharp flashes of radio waves coming from an unknown source, researchers hope that this new live transmission may help them soon be able to pinpoint sources of cosmic transmissions.
The first such fast radio burst was found in 2007 and was discovered only after analyzing older data. Since that time, a total of seven bursts have been found in the older data. The latest burst was detected live by astronomer Emily Petroff and her team using the Parkes radio telescope.
John Mulchaey, acting director of the Carnegie Observatories, says that "these events are one of the biggest mysteries in the universe. Until now, astronomers were not able to catch one of these events in the act."
The researchers believe the signal points to a source for the burst that is approximately 5.5 billion light-years away, near the constellation Aquarius. When it was discovered, researchers tuned twelve more telescopes to help find the source and gather more data about the burst.
"Using the Swift space telescope we can observe light in the X-ray region and we saw two X-ray sources at that position," astrophysicist at the Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Daniele Malesani says.
Then the two X-ray sources were observed using the Nordic Optical Telescope on La Palma.
"We observed in visible light and we could see that there were two quasars, that is to say, active black holes. They had nothing to do with the radio wave bursts, but just happen to be located in the same direction," astrophysicist Giorgos Leloudas says.
Astronomers have ruled out possible candidates for the source of the radio wave like long gamma-ray bursts, as well as nearby supernovae. Giant flares or short, low-energy gamma-ray bursts are still likely contenders, and some even speculate the possibility of extraterrestrial life to be the cause, although this is likely never to be confirmed.
"The fact that we did not see light in other wavelengths eliminates a number of astronomical phenomena that are associated with violent events such as gamma-ray bursts from exploding stars and supernovae, which were otherwise candidates for the burst" Malesani says. "The theories are now that the radio wave burst might be linked to a very compact type of object - such as neutron stars or black holes and the bursts could be connected to collisions or 'star quakes'."
