APOD: Gravity's Grin (2019 Oct 26)

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APOD: Gravity's Grin (2019 Oct 26)

Post by APOD Robot » Sat Oct 26, 2019 4:06 am

Image Gravity's Grin

Explanation: Albert Einstein's general theory of relativity, published over 100 years ago, predicted the phenomenon of gravitational lensing. And that's what gives these distant galaxies such a whimsical appearance, seen through the looking glass of X-ray and optical image data from the Chandra and Hubble space telescopes. Nicknamed the Cheshire Cat galaxy group, the group's two large elliptical galaxies are suggestively framed by arcs. The arcs are optical images of distant background galaxies lensed by the foreground group's total distribution of gravitational mass. Of course, that gravitational mass is dominated by dark matter. The two large elliptical "eye" galaxies represent the brightest members of their own galaxy groups which are merging. Their relative collisional speed of nearly 1,350 kilometers/second heats gas to millions of degrees producing the X-ray glow shown in purple hues. Curiouser about galaxy group mergers? The Cheshire Cat group grins in the constellation Ursa Major, some 4.6 billion light-years away.

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Ann
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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by Ann » Sat Oct 26, 2019 4:37 am

X-ray - NASA/CXC/J. Irwin et al. ; Optical - NASA/STScI
Poster by janneman99|redbubble


















Yes, in the end only the cosmic gravity grin remains!

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by rj rl » Sat Oct 26, 2019 8:41 am

What's the bright glowing blob near the right edge?

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Ann
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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by Ann » Sat Oct 26, 2019 9:33 am

rj rl wrote:
Sat Oct 26, 2019 8:41 am
What's the bright glowing blob near the right edge?
Since the blob at right is purple, and since purple in this image means X-rays, it is an X-ray source of some kind. It could conceivably be a brilliant distant AGN whose galaxy is too faint to show up, or it could, perhaps, be a local magnetar or neutron star.

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by rj rl » Sat Oct 26, 2019 10:39 am

Not a chance that it's related to the merger?

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by orin stepanek » Sat Oct 26, 2019 11:36 am

today's APOD makes a nice smiley face! :D
Orin

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by Chris Peterson » Sat Oct 26, 2019 2:04 pm

rj rl wrote:
Sat Oct 26, 2019 10:39 am
Not a chance that it's related to the merger?
The different elements are at vastly different distances from each other.
Chris

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by bystander » Sat Oct 26, 2019 2:38 pm

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by Guest » Sat Oct 26, 2019 5:59 pm

I was thinking more along the lines of Happy Hallowe'en from Interstellar Space.

WWW

Re: APOD: Gravity's Grin (2019 Oct 26)

Post by WWW » Sun Oct 27, 2019 2:53 am



I was thinking it might be distant intelligent life just starting to get into intergalactic fast food advertising.

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by DAMGEM » Sat Nov 02, 2019 6:00 am

WOULD MOST OR ALL LIFE IN MERGING GALACTIC BODIES BE AT GREAT RISK WITH THE GENERATED TEMPERATURES.

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by Chris Peterson » Sat Nov 02, 2019 1:37 pm

DAMGEM wrote:
Sat Nov 02, 2019 6:00 am
WOULD MOST OR ALL LIFE IN MERGING GALACTIC BODIES BE AT GREAT RISK WITH THE GENERATED TEMPERATURES.
The temperatures are high, but the energy density is low. The energies involved would pose little or no risk. The primary risk would be in areas of high star density, where gravitational perturbations could alter planetary orbits, which would be disastrous for complex life, and possibly even for simple life.
Chris

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Re: APOD: Gravity's Grin (2019 Oct 26)

Post by neufer » Sat Nov 02, 2019 2:50 pm

Chris Peterson wrote:
Sat Nov 02, 2019 1:37 pm
DAMGEM wrote:
Sat Nov 02, 2019 6:00 am

WOULD MOST OR ALL LIFE IN MERGING GALACTIC BODIES BE AT GREAT RISK WITH THE GENERATED TEMPERATURES.
The temperatures are high, but the energy density is low. The energies involved would pose little or no risk. The primary risk would be in areas of high star density, where gravitational perturbations could alter planetary orbits, which would be disastrous for complex life, and possibly even for simple life.
Art Neuendorffer