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APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 4:06 am
by APOD Robot
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.
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 4:37 am
by Ann
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!
Ann
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 8:41 am
by rj rl
What's the bright glowing blob near the right edge?
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 9:33 am
by Ann
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.
Ann
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 10:39 am
by rj rl
Not a chance that it's related to the merger?
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 11:36 am
by orin stepanek
today's APOD makes a nice smiley face!
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 2:04 pm
by Chris Peterson
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.
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 2:38 pm
by bystander
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Oct 26, 2019 5:59 pm
by Guest
I was thinking more along the lines of Happy Hallowe'en from Interstellar Space.
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sun Oct 27, 2019 2:53 am
by WWW
I was thinking it might be distant intelligent life just starting to get into intergalactic fast food advertising.
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Nov 02, 2019 6:00 am
by DAMGEM
WOULD MOST OR ALL LIFE IN MERGING GALACTIC BODIES BE AT GREAT RISK WITH THE GENERATED TEMPERATURES.
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Nov 02, 2019 1:37 pm
by Chris Peterson
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.
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Sat Nov 02, 2019 2:50 pm
by neufer
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.
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Mon Nov 23, 2020 5:04 am
by gillygoose19
where is it located
Re: APOD: Gravity's Grin (2019 Oct 26)
Posted: Mon Nov 23, 2020 6:27 pm
by bystander
gillygoose19 wrote: ↑Mon Nov 23, 2020 5:04 amwhere is it located
