Radio waves emitted from ALESS65 as observed by the Australia Telescope Compact Array. Credit: Huynh et al.
NGC5044, a ‘red and dead’ galaxy like ALESS65 will become in about 25 million years. (the X-Rays are shown in blue and the visible light is shown in yellow). Credit: X-ray: NASA/CXC/Stanford Univ/N.Werner et al; Optical: DSS)
Arp220, a nearby ‘Ultraluminous Infrared Galaxy’ similar to what ALESS65
would look like if it were closer to Earth. Credit: NASA, ESA, and the
Hubble Team
Dr Minh Huynh, Credit: ICRAR
Astronomers have studied the carbon monoxide in a galaxy over 12 billion light years from Earth and discovered that it’s running out of gas, quite literally, and headed for a ‘red and dead’ future.
The galaxy, known as ALESS65, was observed by the Atacama Large
Millimeter Array (ALMA) in 2011 and is one of less than 20 known distant
galaxies to contain carbon monoxide.
Dr Minh Huynh from The University of Western Australia node of the
International Centre for Radio Astronomy Research (ICRAR) led the team
on their search for galactic carbon monoxide in work published today in
the Monthly Notices of the Royal Astronomical Society.
“We’re familiar with carbon monoxide here on Earth as the deadly gas
that can cause suffocation, but in galaxies it plays an important role
in the lifecycle of stars,” said Huynh.
“Out of the galaxies that we know contain carbon monoxide, less than
20 are as far away from Earth as ALESS65. Out of the billions of
galaxies out there, the detections are very rare!”
Huynh, who grew up in Perth, said that at first astronomers didn’t
think there could be massive ‘red and dead’ galaxies in the distant
Universe, so studying galaxies heading towards that fate is important to
solve the puzzle of their existence.
Using the Australia Telescope Compact Array (ATCA) radio telescope in
NSW, Australia, Huynh and the team worked out how much carbon monoxide
they could see in ALESS65 and extrapolated that out into how much fuel
the galaxy has left – how much gas it has.
“All galaxies have a certain amount of fuel to make new stars,” said Huynh.
“Our galaxy, the Milky Way, has about five billion years before it
runs out of fuel and becomes ‘red and dead’, but ALESS65 is a gas
guzzler and only has 10s of millions of years left – very fast in
astronomical terms.”
The team also combined their observations of the galaxy with the
original data from ALMA to work out how similar ALESS65 is to galaxies
nearer to Earth.
“We were able to work out the strength of the UV radiation in
ALESS65; it’s similar to some ‘starbursting’ galaxies in the local
universe, but the stars in ALESS65 are forming in much larger areas when
compared to local galaxies,” said Huynh.
The team will now turn their attentions to the search for carbon monoxide in another galaxy near to ALESS65, named ALESS61.
“Finding and studying carbon monoxide in more galaxies will tell us
even more about how stars formed in the early days of the Universe and
help solve the mystery of far away ‘red and dead’ galaxies” said Huynh.
ICRAR is a joint venture between Curtin University and The University
of Western Australia with support and funding from the State Government
of Western Australia.
Original Publication
“Detection of molecular gas in an ALMA [CII]-identified Submillimetre
Galaxy at z=4.44” Huynh et al. Monthly Notices of the Royal
Astronomical Society (Oxford University Press), Published 9th of July
2014.
Available at: http://mnrasl.oxfordjournals.org/lookup/doi/10.1093/mnrasl/slu077 (Pre
press copy: http://arxiv.org/abs/1407.0463).
Contacts
Dr Minh HuynhICRAR - UWA
Ph: +61 8 6488 4594
M: +61 413 698 670
E: minh.huynh@icrar.org
Kirsten Gottschalk
Media Contact, ICRAR
Ph: +61 8 6488 7771
M: +61 438 361 876
E: kirsten.gottschalk@icrar.org
David Stacey
Media Manager, UWA
Ph: +61 8 6488 3229
M: +61 432 637 716
E: david.stacey@uwa.edu.au
