A radio contour overlay showing the newly-discovered Matorny-Terentev
Cluster RGZ-CL J0823.2+0333. Credit: Banfield et al./SDSS.
Two volunteer participants in an international citizen science
project have had a rare galaxy cluster that they found named after them.
The
pair pieced together the huge C-shaped structure from much smaller
images of cosmic radio waves shown to them as part of the web-based
program Radio Galaxy Zoo.
The discovery surprised the astronomers
running the program, said the lead author of the study Dr Julie Banfield
of the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) at
The Australian National University (ANU).
“They found something
that none of us had even thought would be possible,” said Dr
Banfield.More than 10,000 volunteers have joined in with Radio Galaxy
Zoo, classifying over 1.6 million images from NASA’s Wide-Field Infrared
Survey Explorer telescope and the NRAO Very Large Array in New Mexico,
USA.
“The dataset is just too big for any individual or small team to plough through – but we have already reached almost 60% completeness” said Dr Banfield.
The project is led by Dr Banfield
and Dr Ivy Wong who is based at the International Centre for Radio
Astronomy Research (ICRAR) at The University of Western Australia.
“Although
radio astronomy is not as pretty as optical images from the Hubble
space telescope, people can find cool things, like black holes, quasars,
spiral galaxies or clusters of galaxies.”
The astronomers
classified the newly-discovered feature as a wide angle tail (WAT) radio
galaxy, named for the C-shaped tail shape of highly energetic jets of
plasma which are being ejected from it.
It is part of a previously unreported sparsely-populated galaxy cluster and one of the biggest ever found.
Their discovery has now been published in the Monthly Notices of the Royal Astronomical Society with the two volunteers included as co-authors.
“This
radio galaxy might have had two distinct episodes of activity during
its lifetime, with quiet times of approximately 1 million years in
between.” said Radio Galaxy Zoo science team member and co-author Dr
Anna Kapinska, also of CAASTRO / ICRAR at the University of Western
Australia.
But the discovery of the Matorny-Terentev Cluster
RGZ-CL J0823.2+0333, now bearing the names of the two citizen
scientists, means even more than having added another piece to our
cosmic puzzle.
While the unusual, bent shape of WATs has proven an
excellent beacon for the detection of galaxy clusters, it will always
be difficult to be detected by algorithms – which is where citizen
science can play a huge part.
Through big projects such as Radio Galaxy Zoo, citizen science has established itself as a powerful research tool for astronomy, especially looking at the future challenges such as the EMU survey in Australia – the “Evolutionary Map of the Universe” with the Australian Square Kilometre Array Pathfinder (ASKAP) – and MeerKAT MIGHTEE in South Africa.
“Expanding on projects such
as Radio Galaxy Zoo or on machine-learning techniques will be key to
finding these unusual structures and to studying galaxy clusters.” said
Dr Banfield.
The team of Radio Galaxy Zoo has entered their
project in this year’s Australian Museum Eureka Prizes whose winners are
expected to be announced during National Science Week.
Contact details Dr Julie Banfield (ANU)
T: +61 2 6197 0171
M: 0415 753 414
Email: julie.banfield@anu.edu.au
Dr Anna Kapinska (CAASTRO/ICRAR-UWA)
T: +61 8 6488 7748
M: 0474 476 790
Email: anna.kapinska@icrar.org
Dr Ivy Wong (ICRAR-UWA)
T: +61 8 6488 7761
M: 0402 828 363
Email: ivy.wong@icrar.org
Multimedia
Simulation of plasma jets - video courtesy of Brian O'Neill, Institute for Astrophysics, University of Minnesota
