Dark Matter Can Form Tiny, Cold 'Clumps.' Scientists Have Found the Smallest Ones Yet.

These Hubble Space Telescope images include reveals four distorted images of a background quasar and its host galaxy surrounding the central core of a foreground massive galaxy. Using the effects of gravity within this system, researchers were able to indirectly detect dark matter and find clumps of "cold dark matter" smaller than any similar clumps ever detected.
These Hubble Space Telescope images include reveals four distorted images of a background quasar and its host galaxy surrounding the central core of a foreground massive galaxy. Using the effects of gravity within this system, researchers were able to indirectly detect dark matter and find clumps of "cold dark matter" smaller than any similar clumps ever detected. (Image credit: NASA, ESA, A. Nierenberg (JPL) and T. Treu (UCLA))

It turns out that dark matter forms smaller "clumps" than scientists thought, confirming a fundamental prediction about the mysterious substance.

Dark matter is the invisible stuff that is said to make up about 27% of all of the mass in the universe. Though researchers cannot directly observe dark matter because it doesn't emit light or energy, scientists think it dominates all of outer space — and even Earth. 

It may sound weird, but dark matter gets "clumpy." 

According to the widely accepted "cold dark matter" theory, all galaxies form within clouds of dark matter, which is made up of slow-moving, or "cold," particles. These "cold" dark matter particles form structures, or "clumps," that can be as "small" as an airplane or as massive as hundreds of thousands of Milky Way galaxies, according to a NASA statement

Related: Vera Rubin: The Astronomer Who Brought Dark Matter to Light

Now, a recent study, which used a new observation technique with NASA's Hubble Space Telescope, provides incredible evidence for the "cold dark matter" theory and shows how the mysterious stuff forms smaller clumps than scientists previously thought. 

"We made a very compelling observational test for the cold dark matter model, and it passes with flying colors," Tommaso Treu, a professor in the Division of Astronomy and Astrophysics at the University of California, Los Angeles and a member of the team that made the Hubble observations, said in the NASA statement. 

To indirectly observe and study dark matter, researchers use the effects of gravity in nearby stars and galaxies to detect dark matter and glean information about it. Previously, researchers have found evidence of clumps of dark matter near large and medium-size galaxies, but the clumps found in these new observations are the smallest ever detected. 

Because scientists hadn't seen such small clumps of dark matter until now, some researchers had suggested that there might be "warm" dark matter particles that move around too quickly to form large structures, and thus form only smaller clumps. But with these observations, it's clear that "cold" dark matter particles can also form small clumps. 

As scientists continue to (indirectly) observe and study dark matter, the mysterious material becomes less … well … mysterious. This work both reveals new information about dark matter and works to confirm presumptions made about the material that makes up such an enormous percentage of our universe. 

"Dark matter is colder than we knew at smaller scales," Anna Nierenberg, a researcher at NASA's Jet Propulsion Laboratory who led the Hubble survey, said in the statement. "Astronomers have carried out other observational tests of dark matter theories before, but ours provides the strongest evidence yet for the presence of small clumps of cold dark matter. By combining the latest theoretical predictions, statistical tools and new Hubble observations, we now have a much more robust result than was previously possible."

The researchers behind these observations will present their results at the 235th meeting of the American Astronomical Society in Honolulu, Hawaii.

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Chelsea Gohd
Senior Writer

Chelsea “Foxanne” Gohd joined Space.com in 2018 and is now a Senior Writer, writing about everything from climate change to planetary science and human spaceflight in both articles and on-camera in videos. With a degree in Public Health and biological sciences, Chelsea has written and worked for institutions including the American Museum of Natural History, Scientific American, Discover Magazine Blog, Astronomy Magazine and Live Science. When not writing, editing or filming something space-y, Chelsea "Foxanne" Gohd is writing music and performing as Foxanne, even launching a song to space in 2021 with Inspiration4. You can follow her on Twitter @chelsea_gohd and @foxannemusic.

  • rod
    Admin said:
    It turns out that dark matter forms smaller "clumps" than scientists thought, confirming a fundamental prediction about the mysterious substance.

    Dark Matter Can Form Tiny, Cold 'Clumps.' Scientists Have Found the Smallest Ones Yet. : Read more

    The report shows HST images that support Einstein GR and gravitational lensing. I like to dig a bit deeper, here are two reports on WFI 2033-4723 (one of the HST views shown) showing its redshift number or z number and arcminute resolution in the spectra. H0LiCOW - X. Spectroscopic/imaging survey and galaxy-group identification around the strong gravitational lens system WFI 2033-4723
    Here is another report, https://ui.adsabs.harvard.edu/abs/2019MNRAS.tmp.3214N/abstract
    Reply
  • Torbjorn Larsson
    Precision astronomy is doing amazing things on dark matter structure right now!

    The upper range for the dark matter blob masses in the paper are 1 - 1,000 Msolar mass https://hubblesite.org/uploads/science_paper/file_attachment/526/stz3480.pdf ].

    That fits nicely with the GD-1 streamer hole with its associated local sinusoidal wave centered on the hole. The discovery paper suggest - due to lack of visible candidates and a need for an extended mass - a passing by dark matter blob of ~ 10 Msolar mass https://www.skyandtelescope.com/astronomy-news/evidence-dark-matter-clump-milky-way/ ]: "According to the group’s simulations, the object would have been hefty — at least 5 million solar masses — but would have spanned between 60 and 130 light-years."

    And that span is about the size of the Radcliff Wave similar hole that the ongoing AAS conference showed us the other day https://phys.org/news/2020-01-milky-reveals-giant-stellar-nurseries.html ]. There isn't any satellite galaxies on distances that could have passed by at the time I think , so a dark matter blob could be behind the sinusiodal GD-1 like wave.
    Reply
  • rod
    Torbjorn Larsson said:
    Precision astronomy is doing amazing things on dark matter structure right now!

    The upper range for the dark matter blob masses in the paper are 1 - 1,000 Msolar mass https://hubblesite.org/uploads/science_paper/file_attachment/526/stz3480.pdf ].

    That fits nicely with the GD-1 streamer hole with its associated local sinusoidal wave centered on the hole. The discovery paper suggest - due to lack of visible candidates and a need for an extended mass - a passing by dark matter blob of ~ 10 Msolar mass https://www.skyandtelescope.com/astronomy-news/evidence-dark-matter-clump-milky-way/ ]: "According to the group’s simulations, the object would have been hefty — at least 5 million solar masses — but would have spanned between 60 and 130 light-years."

    And that span is about the size of the Radcliff Wave similar hole that the ongoing AAS conference showed us the other day https://phys.org/news/2020-01-milky-reveals-giant-stellar-nurseries.html ]. There isn't any satellite galaxies on distances that could have passed by at the time I think , so a dark matter blob could be behind the sinusiodal GD-1 like wave.

    Good information and links provided, thanks.
    Reply
  • sgtnos
    rod said:
    The report shows HST images that support Einstein GR and gravitational lensing. I like to dig a bit deeper, here are two reports on WFI 2033-4723 (one of the HST views shown) showing its redshift number or z number and arcminute resolution in the spectra. H0LiCOW - X. Spectroscopic/imaging survey and galaxy-group identification around the strong gravitational lens system WFI 2033-4723
    Here is another report, https://ui.adsabs.harvard.edu/abs/2019MNRAS.tmp.3214N/abstract
    Okay, so this is my argument. We already know about the fact that space is not a perfect vacuum and that we are even in a dust cloud. We constantly find things we could not have seen before (usually not something new). The idea that dark matter is what "holds" everything together is incorrect. Again, it requires that gravity be a constant. Since it is not, I would argue that it is plasma and due to electromagnetic forces. They have already found powerful electric currents in space and are constantly surprised by the magnetic fields in our solar system. Things they never predicted. We ignore that the only planets/moons that have weak atmospheres have weak magnetic fields and the opposite for the ones that have a decent atmosphere. Stars that are older than the galaxy and stars that have transuranic elements exist. The effect they are usually claiming is gravitational lensing is typically atmospheric/photospheric lensing. This is the effect you see when the light gets super bright during an eclipse. We do not see star formation that occurs in a similar way to gravitational collapse because that would mean that a force is acting upon itself and that violates thermodynamics.
    Reply
  • orsobubu
    I don't believe dark matter does exist in the first place (nor dark energy) and I'm waiting for the moment when it will turn out these images are something totally different
    Reply
  • sgtnos
    rod said:
    The report shows HST images that support Einstein GR and gravitational lensing. I like to dig a bit deeper, here are two reports on WFI 2033-4723 (one of the HST views shown) showing its redshift number or z number and arcminute resolution in the spectra. H0LiCOW - X. Spectroscopic/imaging survey and galaxy-group identification around the strong gravitational lens system WFI 2033-4723
    Here is another report, https://ui.adsabs.harvard.edu/abs/2019MNRAS.tmp.3214N/abstract
    Cosmological constant abandoned Main article: Cosmological constantAfter Hubble's discovery was published, Albert Einstein abandoned his work on the cosmological constant, which he had designed to modify his equations of general relativity to allow them to produce a static solution, which he thought was the correct state of the universe. The Einstein equations in their simplest form model generally either an expanding or contracting universe, so Einstein's cosmological constant was artificially created to counter the expansion or contraction to get a perfect static and flat universe. After Hubble's discovery that the universe was, in fact, expanding, Einstein called his faulty assumption that the universe is static his "biggest mistake". On its own, general relativity could predict the expansion of the universe, which (through observations such as the bending of light by large masses, or the precession of the orbit of Mercury) could be experimentally observed and compared to his theoretical calculations using particular solutions of the equations he had originally formulated.
    In 1931, Einstein made a trip to Mount Wilson to thank Hubble for providing the observational basis for modern cosmology.
    The cosmological constant has regained attention in recent decades as a hypothesis for dark energy.
    Einstein had a different theory until Hubble "Proved" him wrong through his observations. Again, we are in a cloud of dust that Hubble did not know about when he made his measurements. The equipment he used to do this is less accurate than what people have at home and this effectively ended the search for an answer. If Hubble was wrong, then it doesn't allow for Einstein work, his own WORDS. The bending of light that has been observed is better explained through atmospheric lensing.
    Hubble was able to plot a trend line from the 46 galaxies he studied and obtain a value for the Hubble constant of 500 km/s/Mpc (much higher than the currently accepted value due to errors in his distance calibrations). (See cosmic distance ladder for details.)


    Hubble's law - Wikipedia
    en.wikipedia.org
    This is so wrong it is terrible. It acts as if space is homogenous and it is in the article very clearly.
    Idealized Hubble's lawedit] The mathematical derivation of an idealized Hubble's law for a uniformly expanding universe is a fairly elementary theorem of geometry in 3-dimensional Cartesian/Newtonian coordinate space, which, considered as a metric space, is entirely homogeneous and isotropic (properties do not vary with location or direction). Simply stated the theorem is this:


    Any two points which are moving away from the origin, each along straight lines and with speed proportional to distance from the origin, will be moving away from each other with a speed proportional to their distance apart.
    Click to expand...
    In fact this applies to non-Cartesian spaces as long as they are locally homogeneous and isotropic; specifically to the negatively and positively curved spaces frequently considered as cosmological models (see shape of the universe).

    An observation stemming from this theorem is that seeing objects recede from us on Earth is not an indication that Earth is near to a center from which the expansion is occurring, but rather that every observer in an expanding universe will see objects receding from them.
    Reply
  • Common Sense Dictates
    Go look again. Those are photos from Hubble, not artist renditions.
    Reply
  • egribble
    Admin said:
    It turns out that dark matter forms smaller "clumps" than scientists thought, confirming a fundamental prediction about the mysterious substance.

    Dark Matter Can Form Tiny, Cold 'Clumps.' Scientists Have Found the Smallest Ones Yet. : Read more
    Reply
  • egribble
    We are talking about theoretical physics here. It does not surprise me that dark matter is clumpy, as dark matter curves space inwards (i.e. gravity) so should congregate and even orbit it's centre of mass. The problem with theoretical physics is that people can only suggest theories based on what is observable. When we look at things on a very small or very large scale our whole concept of reality disappears. Our brains evolved to cope with survival on the two dimensional African Savannah. It is a bit hard to contemplate concepts like three dimensional curving, time being the flow to increasing entropy etc. It is simply not known whether or not any of these theories are correct, scientists can only observe.
    Reply
  • egribble
    Common Sense Dictates said:
    Go look again. Those are photos from Hubble, not artist renditions.
    Reply