Meet Dragonfly 44, the galaxy made of 99.9% dark matter

Just an article i found interesting and sharing with you.

SOURCE

A massive galaxy consisting almost entirely of dark matter has been discovered, using the world’s most powerful telescopes.
Dark matter is the invisible ‘gravitational glue' that holds galaxies together and is thought to make up five sixths of the universe’s mass. The galaxy, named Dragonfly 44, is roughly the same mass as the Milky Way, but our galaxy has a hundred times more stars.

Despite being relatively nearby Earth, the intriguing galaxy has evaded the attention of astronomers for decades because it is very dim. However, an international team of astronomers spotted it last year using the WM Keck Observatory and the Gemini North Telescope in Manuakea, Hawaii, when the Dragonfly Telephoto Array observed a region of the sky in the constellation Coma.
They realised the galaxy had to have more than meets the eye; it has so few stars that it quickly would be ripped apart unless something was holding it together – dark matter.

originally posted by: Mianeye
Just an article i found interesting and sharing with you.

They realised the galaxy had to have more than meets the eye; it has so few stars that it quickly would be ripped apart unless something was holding it together – dark matter.

I wonder how that equates with the big bang.

a reply to: Mianeye
There is gonna be the most remote resort of our universe I guess. When they start to sell galaxies I would definitely buy that one, take my fishing poles, throw my smartphone, and take off.

a reply to: Mianeye

Very cool find.

Speaking about "fluffiest galaxies" last year, of which Dragonfly 44 is one, Dr van Dokkum said: “If t If the Milky Way is a sea of stars, then these newly discovered galaxies are like wisps of clouds. “They are found in a dense, violent region of space filled with dark matter and galaxies whizzing around, so we think they must be cloaked in their own invisible dark matter ‘shields’ that are protecting them from this intergalactic assault.” Finding a galaxy with the mass of the Milky Way that is almost entirely dark was unexpected. Roberto Abraham, Professor of Astronomy at the University of Toronto and a co-author of the study said: “We have no idea how galaxies like Dragonfly 44 could have formed.

From article

I wonder if we understood Dark Matter 'shields', could we could better explain the glueing effect Dark Matter seems to have on other Matter?

Thanks for posting, S&F

a reply to: Mianeye

Why does it have to be held together by dark matter? Because some twit at the U of T says so lol? Maybe the Galaxy has a reasonably homogeneous distribution of asteroids and comets? Maybe there are a lot of primary state black holes orbiting each other at suffixes velocity that they don't mega? Maybe it's just a bigger ass nebula?

Cheers - Dave

a reply to: bobs_uruncle

Dark matter is their answer for anything they can't explain.

Math doesn't work? Let's invent a theoretical substance to make it work.

It's the theoretical physicist's "god of the gaps".

99.9 dark mater.
um??? we Can see it!

Check out the beast of a telescope that made the discovery:

"In July, 2014, Dr. Roberto Abraham, our pal from the University of Toronto, and his associates from Yale University made headlines when their 10-eyed, Paramount ME II-mounted, TheSkyX Professional Edition-controlled, multi-lens array discovered several new ultra-low surface brightness objects near M101."
www.bisque.com...

Individually these telescopes are akin to amateur sized short focal length refractors, with custom coatings to minimize internal light scattering. By combining multiple such telescopes into a single array you get the effective light collecting area of a much larger telescope, but with the wide field of view of a short focal length telescope.
arxiv.org...

a reply to: Mianeye

When people use 99.9% instead of 100% whatever their proclaiming is most likely false.

originally posted by: bobs_uruncle
a reply to: Mianeye

Why does it have to be held together by dark matter? Because some twit at the U of T says so lol? Maybe the Galaxy has a reasonably homogeneous distribution of asteroids and comets?

Asteroids and comets are considered dark matter. Dark matter is anything that is non-luminous.

The OP article certainly doesn't rule out asteroids in any way when it says this:

“Motions of the stars tell you how much matter there is,” Pieter van Dokkum of Yale University explained. “They don’t care what form the matter is, they just tell you that it’s there.

There are some reasons to think that baryonic dark matter like asteroids, and black holes can't explain dark matter observations completely based on things like gravitational microlensing experiments, though they obviously form some component of it, but in this particular case I don't think we really know how much of the dark matter might be baryonic. I don't think asteroids have been ruled out as a possible source of dark matter, but if our own solar system is any example, they don't account for much of the mass here, which is only estimated to be 4% of the mass of Earth's moon, which rounded to the nearest 1% accounts for 0% of the mass of our solar system. It could be different in other galaxies, so maybe we shouldn't infer too much from local observations.

You may be under the assumption that "dark matter" refers exclusively to the non-baryonic type and while that is a common usage of the term because it's the undiscovered component we are searching for in dark matter experiments, it's not the only usage of the term "dark matter". It really could be anything that explains the motions of the stars in this case.

a reply to: Arbitrageur

Cosmology, is getting better but it still seems to be about 50% science and 50% consensus driven prophesy. If the law worked like science, allowing all manner of circumstantial evidence, we would all be in jail for something.

I realize that dark matter could be construed as anything non-luminous, but luminosity requires a certain proximity based on the level of available light. I do take issue with the "magic" and highly exotic premise of dark matter as promoted by mainstream science. If all laws to be valid apply equally to all space-time, then we should easily find this alleged dark matter locally. Maybe I should go up the street and have look carrying a sign that says, "Dark Matter Matters."

When science promotes an unseen thing and says have faith in our understanding, it's a lot like the church, science becomes a religion and is no longer science, in this case, it becomes cosmoligion. Does gravity wave interferometry by temporal proxy indicate that time changes its rate by itself or time changes its rate due to gravity or time changes it's rate due to some other influence? I don't have a definitive answer, but I am quite sure cosmologists would dream up a definitive consensus driven answer that has more to do with faith in their opinions than actual science.

Cheers - Dave

the Galaxy with 100x less stars than our own Milky-Way Galaxy
bring to mind the first day of Creation found in Genesis

"....And the earth was without form, and void; and #darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
And God said, Let there be light: and there was light ... thus was the First Day-&-Night

Dragonfly 44 must be an example of a Galaxy & the Star systems inside it... in Its' own Genesis Stage of development



#darkness -> perhaps darkness was the description of what we call 'dark matter' in today's Physicists circles.

originally posted by: bobs_uruncle
When science promotes an unseen thing and says have faith in our understanding, it's a lot like the church, science becomes a religion and is no longer science, in this case, it becomes cosmoligion.

But a galaxy rotation curve is not an unseen thing, it is observed. So a galaxy rotation curve is nothing like religion.

If you have a better explanation for galaxy rotation curves than dark matter, let's hear it, but alternatives have been considered such as MOND and they not only fail, but in this example I suspect MOND fails quite spectacularly.