Parkes Radio Telescope Discovers RRATs in Space
A team of astronomers from Australia, the UK, USA, Italy, and Canada using the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) Parkes radio telescope in eastern Australia has found a new kind of cosmic object: a small, compressed Neutron Star that shows no activity most of the time but once in a while spits out a single burst of high energy radio waves. This new class of objects have been dubbed Rotating Radio Transients or RRATs.
These new objects are likely to be related to conventional radio pulsars (small stars that emit regular pulses of radio waves, up to hundreds of times a second). But the new objects probably far outnumber their old cousins, the scientists say.
Eleven RRATs have been found, first detected by the Parkes Multibeam Pulsar Survey and then observed again several times. Their isolated bursts last for between two and 30 milliseconds. In between, for times ranging from four minutes to three hours, they are silent.
"These things were very difficult to pin down," says CSIRO's Dr Dick Manchester, a member of the research team and a veteran pulsar hunter. "For each object we've been detecting radio emission for less than one second a day. And because these are single bursts, we've had to take great care to distinguish them from terrestrial radio interference."
By analysing the burst arrival times, the astronomers have found that 10 of the 11 sources have underlying periods of between 0.4 seconds and seven seconds. It is this that suggests that they are rotating neutron stars.
Because RRATs are silent most of the time, the chance of being able to detect one is low. Many more must lurk unseen in our Galaxy, the astronomers argue — perhaps a few hundred thousand. The number of 'normal' radio pulsars in our Galaxy is estimated to be about 100,000.
Unlike some other kinds of stars that show periodic eruptions, the RRATs show no evidence for being in binary systems (that is, orbiting another star).
For More Information:
http://www.atnf.csiro.au/news/press/rrats.html
These new objects are likely to be related to conventional radio pulsars (small stars that emit regular pulses of radio waves, up to hundreds of times a second). But the new objects probably far outnumber their old cousins, the scientists say.
Eleven RRATs have been found, first detected by the Parkes Multibeam Pulsar Survey and then observed again several times. Their isolated bursts last for between two and 30 milliseconds. In between, for times ranging from four minutes to three hours, they are silent.
"These things were very difficult to pin down," says CSIRO's Dr Dick Manchester, a member of the research team and a veteran pulsar hunter. "For each object we've been detecting radio emission for less than one second a day. And because these are single bursts, we've had to take great care to distinguish them from terrestrial radio interference."
By analysing the burst arrival times, the astronomers have found that 10 of the 11 sources have underlying periods of between 0.4 seconds and seven seconds. It is this that suggests that they are rotating neutron stars.
Because RRATs are silent most of the time, the chance of being able to detect one is low. Many more must lurk unseen in our Galaxy, the astronomers argue — perhaps a few hundred thousand. The number of 'normal' radio pulsars in our Galaxy is estimated to be about 100,000.
Unlike some other kinds of stars that show periodic eruptions, the RRATs show no evidence for being in binary systems (that is, orbiting another star).
For More Information:
http://www.atnf.csiro.au/news/press/rrats.html
Funding Member
