The Apertif Radio Transient System (ARTS), the new, high-speed, wide-field radio camera for the Westerbork Synthesis Radio Telescope, has for the first time detected a bright Fast Radio Burst on 31 August 2017.
Published by the editorial team, 7 September 2017
Fast Radio Bursts (FRBs) are extremely bright flashes of radio light that travel billions of light years to reach Earth. They were discovered a decade ago, but their nature continues to be largely unknown. That’s why we need new instruments with a high sensitivity and speed to measure them.
ARTS is such an instrument: it consists of the revolutionary new Apertif front ends (the eyes), an exceedingly powerful hybrid FPGA-GPU supercomputer (the brain), operating using new firmware and software algorithms (the thoughts). ALERT will investigate the Northern Sky with unprecedented speed and precision, to determine the nature of some of the most powerful flashes and explosions in the Universe.
Luminous radio source
The final ARTS GPU hardware was just installed in the Westerbork server room, in the last week of Aug 2017. “On Thursday 31 August, we started commissioning of this system, by observing the repeating Fast Radio Burst source 121102. Given the limited sensitivity of the single-dish test system, we had low expectations,” says Leon Oostrum, the PhD student from ASTRON/University of Amsterdam who first identified the burst. “But during this observation, ARTS detected an FRB, its first. The burst is very short, and very bright. For about a millisecond it was one of the most luminous radio sources in the sky.”
What in the Universe makes FRBs?
Multiple bright pulses from FRB 121102 at higher frequencies have been detected with the Green Bank Telescope on 26 August. This detection indicates the FRB source may be in a phase of outburst. But what is causing these outbursts? “We don’t know what in the Universe makes FRBs”, says Joeri van Leeuwen from ASTRON, who leads ARTS. “It might be a neutron star, with a super powerful magnetic field, that emits gigantic bright flashes towards Earth. In that case it may resemble a radio pulsar, but with a magnetic field that is over a thousand times more powerful.”
Of the around twenty known FRBs, FRB 121102 is the only one that sends out bursts regularly. “That is why we used it to test our new instrument,” says Van Leeuwen. “We now know that ARTS is working on a single telescope. The next step is to use all twelve telescopes with the instrument, and combine their signals to get a better picture. Hopefully we will find other, and new, FRBs.”
Further details and plots are available here.
Text: Iris Nijman