A British-led team of astronomers have discovered the first galaxy completely devoid of stars. The galaxy (which is a large mass, about 50 million light years away) can only be detected using a radio telescope. First captured by the University of Manchester’s Lovell Telescope in Cheshire, the discovery was also confirmed by the Arecibo telescope in Puerto Rico.
Dark Galaxy, Invisible (Courtesy: PhysOrg)
It is theorized that since galaxies rotate at a fairly fast pace (our own Milky Way complete one rotation in about 250 million years), dark matter is necessary to ensure that the galaxies do not tear themselves apart. Detecting such dark matter hitherto has been elusive. The techniques that led to the discovery of this dark galaxy can undoubtedly be used to detect other dark matter clumps in our own galaxy, and beyond.
Dark Galaxy, Invisible (Courtesy: PhysOrg)
It is theorized that since galaxies rotate at a fairly fast pace (our own Milky Way complete one rotation in about 250 million years), dark matter is necessary to ensure that the galaxies do not tear themselves apart. Detecting such dark matter hitherto has been elusive. The techniques that led to the discovery of this dark galaxy can undoubtedly be used to detect other dark matter clumps in our own galaxy, and beyond.
Darkest Of Them All
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5 Comments:
Gindy, the cause is not explained. Bu the theory behind it is quite robust. According to the theory, a large mass of inert (no nuclear reaction) gas that is rotating rapidly, fails to collapse under its gravity. Since it does not collapse, there is no high pressure zone created that normally triggers a stellar formation.
In my readings, it seems that dark matter is the cohesive force within galaxies that prevents their powerful orbiting motion from tearing themselves apart.
Yet dark energy is the force that seems to be causing the universe to expand at an ever increasing speed.
Surely, if this is the case, there appears to be something within the mass of the galaxy that inhibits the effects of dark energy.
Just a thought...
For a rotating galaxy like the milky way, centrifugal forces keep the stars from flying away. This force is proportional to the mass of the galaxy, and the total visible stellar-mass is not enough to stop the stars from flying apart. Hence, dark matter is supposed to exist inside the galaxy, (in between the galactic arms).
Similarly, a dark galaxy can contain just dark matter (and no dark energy) for it to rotate. Just that it does not contain any luminous stars, like other galaxies.
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