Galaxies in a cluster roughly 300 million light years from Earth could contain as much as 100 times more dark matter than visible matter, according to an Australian study.
The research, published today, used powerful computer simulations to study galaxies that have fallen into the Coma Cluster, one of the largest structures in the Universe in which thousands of galaxies are bound together by gravity.
"It found the galaxies could have fallen into the cluster as early as seven billion years ago, which, if our current theories of galaxies evolution are correct, suggests they must have lots of dark matter protecting the visible matter from being ripped apart by the cluster."
Dark matter cannot be seen directly but the mysterious substance is thought to make up about 84 per cent of the matter in the Universe.
International Centre for Radio Astronomy Research PhD student Cameron Yozin, who led the study, says the paper demonstrates for the first time that some galaxies that have fallen into the cluster could plausibly have as much as 100 times more dark matter than visible matter.
Yozin, who is based at The University of Western Australia, says the galaxies he studied in the Coma Cluster are about the same size as our own Milky Way but contain only one per cent of the stars.
He says the galaxies appear to have stopped making new stars when they first fell into the cluster between seven and ten billion years ago and have been dead ever since, leading astrophysicists to label them "failed" galaxies.
This end to star formation is known as "quenching".
"Galaxies originally form when large clouds of hydrogen gas collapse and are converted to stars--if you remove that gas, the galaxy cannot grow further," Yozin says.
"Falling into a cluster is one way in which this can happen. The immense gravitational force of the cluster pulls in the galaxy, but its gas is pushed out and essentially stolen by hot gas in the cluster itself.
"For the first time, my simulations have demonstrated that these galaxies could have been quenched by the cluster as early as seven billion years ago.
"They have however avoided being ripped apart completely in this environment because they fell in with enough dark matter to protect their visible matter."
This research was motivated by the recent observational discovery of these galaxies by an American and Canadian team led Professor Pieter van Dokkum of Yale University.
Using the data the North American team published last year, Yozin was able to create computer simulations to model how the galaxies evolved into what we can see today.
The study was released in the journal Monthly Notices of the Royal Astronomical Society, published by Oxford University Press.
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 details:
'The quenching and survival of ultra-diffuse galaxies in the Coma cluster' in Monthly Notices of the Royal Astronomical Society. Published online on 20/7/2015 at: http://mnras.
High resolution images are available from the following link. http://www.
Cameron Yozin (ICRAR - UWA)
Ph: +61 8 6488 3819 E: firstname.lastname@example.org M: +61 423 941 128
Pete Wheeler (Media Contact, ICRAR)
Ph: +61 8 6488 7758 E: email@example.com M: +61 423 982 018
UWA Media Office
Ph: +61 8 6488 3229 E: firstname.lastname@example.org
Peter Wheeler | EurekAlert!
Turmoil in sluggish electrons’ existence
23.05.2017 | Max-Planck-Institut für Quantenoptik
Physicists discover that lithium oxide on tokamak walls can improve plasma performance
22.05.2017 | DOE/Princeton Plasma Physics Laboratory
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
23.05.2017 | Earth Sciences
23.05.2017 | Life Sciences
23.05.2017 | Physics and Astronomy