From the Earth Sky News Bulletin
On 11-25-15
A
composite image – combining x-ray and optical images – of the Cheshire
Cat group of galaxies. Optical image from from NASA’s Hubble Space
Telescope and x-ray images from Chandra X-Ray Observatory.
The Chandra X-Ray Observatory released this image on November 23, 2015. It’s a group of galaxies nicknamed
the Cheshire Cat. Some of the features of the “cat” are distant galaxies, whose light has been stretched and bent by
gravitational lensing.
That’s an indication of large amounts of mass between us and these
distant galaxy, and, Chandra says, most of that mass exists in the form
of
dark matter. According to a Chandra
statement about the Cheshire Cat group of galaxies:
…the mass that distorts the faraway galactic light is
found surrounding the two giant ‘eye’ galaxies and a ‘nose’ galaxy. The
multiple arcs of the circular ‘face’ arise from gravitational lensing of
four different background galaxies well behind the ‘eye’ galaxies.
Chandra also said that that its x-ray observations show that that the
two eyes of the cat – and the smaller galaxies associated with them –
are slamming into one another in a colossal collision between galaxies:
Each ‘eye’ galaxy is the brightest member of its own
group of galaxies and these two groups are racing toward one another at
over 300,000 miles [nearly 500,000 km] per hour. Data from NASA’s
Chandra X-ray Observatory (purple) show hot gas that has been heated to
millions of degrees, which is evidence that the galaxy groups are
slamming into one another. Chandra’s X-ray data also reveal that the
left ‘eye’ of the Cheshire Cat group contains an actively feeding
supermassive black hole at the center of the galaxy...
“But I don’t want to go among mad people," Alice remarked.
"Oh, you can’t help that," said the Cat: "we’re all mad here. I’m mad. You’re mad."
"How do you know I’m mad?" said Alice.
"You must be," said the Cat, "or you wouldn’t have come here.”
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