What's large and blue and can wrap itself around an entire galaxy?
A gravitational lens mirage.
Pictured above,
the gravity of a luminous red galaxy
(LRG) has
gravitationally distorted
the light from a much more distant blue galaxy.
More typically, such light bending results in
two discernible images of the distant galaxy,
but here the
lens alignment
is so precise that the background galaxy is distorted into a horseshoe --
a nearly complete ring.
Since such a
lensing effect
was generally predicted in some detail by
Albert Einstein over
70 years ago,
rings like this are now known as
Einstein Rings.
Although LRG 3-757 was discovered in 2007 in data from the
Sloan Digital Sky Survey (SDSS),
the image shown above is a follow-up observation taken with the
Hubble Space Telescope's
Wide Field Camera 3.
Strong gravitational lenses like LRG 3-757 are more than oddities --
their multiple properties allow astronomers to determine the mass and
dark matter
content of the foreground galaxy lenses.
2 comments:
What are the precise distances of the two galxies? Both the foreground and the backgroud one? Is it possible since the ring has repeating features to digitally re image the background galaxy to show what it would look like as if looking at it directly?
It would also be interesting if once someone mapped the distances in the image, say the top ten most prominent galaxies, and perhaps the 10 most distant as there are numerous galactic formations in this photo, perhaps then people would have a real idea of just how far they are in relationship to each other and also how fortunate we are to have the technology to see these images, ones that Einstein himself never thought man would have the technology to visualize the effects of gravitationally lensed galactic formations that is.
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