‘Wonderful milestone’ for NC telescope
SOUTH Africa’s MeerKAT radio telescope, situated in the heart of the Northern Cape, has observed a rare burst of activity from an exotic star, demonstrating outstanding capabilities as a new instrument for scientific exploration and a remarkable discovery machine.
An article published earlier this week in the Astrophysical Journal presents the study of a magnetar – a star that is one of the most magnetic objects known in the universe – that awoke in 2017 from a three-year slumber.
Radio observations that could only be made with MeerKAT, a telescope being built in the Northern Cape, triggered observations with Nasa X-ray telescopes orbiting the Earth.
This first publication in the scientific literature of astronomical discoveries requiring the use of MeerKAT heralds its arrival into the stable of world-class research instruments.
Dr Fernando Camilo, Chief Scientist at the South African Radio Astronomy Observatory (SARAO), which includes the Square Kilometre Array South Africa project, described the setting one year ago.
“On April 26 2017, while monitoring the long-dormant magnetar with the CSIRO Parkes Radio Telescope in Australia, one of our colleagues noticed that it was emitting bright radio pulses every four seconds,” Camilo said.
A few days later Parkes underwent a planned monthlong maintenance shutdown. Although MeerKAT was still under construction, with no more than 16 of its eventual 64 radio dishes available, the commissioning team started regular monitoring of the star 30 000 light years from Earth.
According to Camilo, the MeerKAT observations “proved critical to make sense of the few X-ray photons captured with Nasa’s orbiting telescopes”.
“For the first time X-ray pulses had been detected from this star, every four seconds. Put together, the observations help us to develop a better picture of the behaviour of matter in unbelievably extreme physical conditions, completely unlike any that can be experienced on Earth.”
The article, entitled Revival of the magnetar PSR J1622−4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR, has 208 authors. A handful of these are astronomers specialising in the study of magnetars and related stars. The vast majority belong to the so-called MeerKAT Builders List – hundreds of engineers and scientists overwhelmingly from the SKA South Africa project and commercial enterprises in South Africa that over more than a decade have been developing and building MeerKAT – a project of the South African Department of Science and Technology, in which 75 percent of the overall construction budget has been spent in South Africa.
“MeerKAT is an enormously complex machine,” says Thomas Abbott, MeerKAT programme manager.
“In order to make the exquisitely sensitive images of the radio sky that will allow scientists to better understand how galaxies like the Milky Way have formed and evolved over the history of the universe, the 64 MeerKAT antennas will generate data at enormous rates. The challenges involved in dealing with so much data require clever solutions to a variety of problems at the cutting edge of technology. We have a team of the brightest engineers and scientists in South Africa and the world working on the project, because the problems that we need to solve are extremely challenging, and attract the best,” Abbott said.
“The first scientific publication based on MeerKAT data is a wonderful milestone”, Professor Roy Maartens, SKA SA Research Chair at the University of the Western Cape, said.
“Although MeerKAT isn’t yet complete, it’s now clearly a functioning telescope. We’ve been training a new generation of researchers, and soon our young scientists will be using what promises to be a remarkable discovery machine.”
Early in 2018, SARAO received the first Early Science MeerKAT observing proposals from South African researchers. Later in the year, already approved Large Survey Projects that will use twothirds of the available observing time over five years will start their investigations with the full array of MeerKAT antennas.
These 64 dishes, each 13.5 metres in diameter, are distributed across a span of eight kilometres in a remote area of the Northern Cape. The 64 MeerKAT antennas are standing tall in the Karoo.
The official unveiling of the telescope is being planned for the second half of 2018.