Are gaps in the Andromeda galaxy filled with dark matter? This NASA telescope could find out

A simulated view of the Andromeda galaxy where Roman will search between stars to hunt dark matter
A simulated view of the Andromeda galaxy where Roman will search between stars to hunt dark matter (Image credit: NASA, NASA-GSFC, ASU, Robert Gendler DSS)

Images created by NASA's forthcoming Nancy Grace Roman Space Telescope may allow scientists to search for dark matter between stars.

An international team of researchers believes that gaps present in strings of stars hanging from tightly packed balls of ancient stellar bodies, called globular clusters, could be influenced by dark matter clumps. 

Thus far, astronomers have only been able to study these dangling stellar streams within the Milky Way, meaning our understanding of them is limited. Roman, set to launch in 2027, should be sensitive enough to see these structures in our neighboring galaxy Andromeda — and with such detail it'd be possible to see disruptions caused by dark matter, giving astronomers clues about this elusive substance.

"There are stellar streams in our own galaxy, where we see gaps that might be due to dark matter," Tjitske Starkenburg, team member and a scientist at Northwestern University, said in a statement. "But these gaps also can be formed by other means."

Related: 'Dark force' theory could solve 2 open cosmic mysteries

The team makes the case that, as Roman observes gaps in galaxies other than the Milky Way, it will provide scientists with a better picture of these gaps as a whole. This could ultimately help determine the existence and properties of dark matter clumps.

Reading between the lines (or the stars, rather)

Dark matter is troubling for scientists because, despite the fact it accounts for an estimated 85% of the matter in the universe, they have very little idea what it is.

Dark matter doesn't interact with light, which means it's effectively invisible to our eyes and can't be made up of atoms comprised of the electrons, protons and neutrons that make up "everyday" matter we're used to. Think, stars, planets, flowers, books. Everything we see with the unaided eye — including our bodies — is made up of such "normal" matter. 

Dark matter does interact with gravity, however, and that means the only way that scientists can infer its presence is by looking at how its influence on gravity subsequently influences all that everyday matter and light. 

The fact that dark matter interacts gravitationally is actually fortunate for the evolution of the universe. Some galaxies, for instance, are rotating so fast that the gravity of their visible matter — stars, gas, dust and planets — wouldn't be sufficient to prevent them from pretty much flying apart.

"We see dark matter's effect on galaxies," Christian Aganze, team member and a postdoctoral fellow at Stanford University, said in the statement. "For example, when we model how galaxies rotate, we need extra mass to explain their rotation. Dark matter may provide that missing mass."

Illustration shows streams of stars seen around the Andromeda galaxy (Image credit: NASA, Joseph Olmsted (STScI))

Clues about dark matter may well be dangling from globular clusters, which often contain millions of stars, along with loose stellar streams. That is because scientists think dark matter can "punch holes" in these stellar streams, creating gaps that can be used to assess the nature of this mysterious form of matter. 

"The reason these streams are most interesting to see the effects of these dark matter clumps is twofold," Starkenburg said. "First, these streams 'live' in the extreme outer regions of a galaxy, where there otherwise is very little structure. 

"And second, these streams are intrinsically very thin because they formed from dense clusters of stars, which means that you can see gaps or any disturbance much more easily.”

This isn't a new idea, but it is one that hasn't been fully exploited to get to the bottom of the dark matter problem. Current space telescopes and ground-based instruments are limited to searching for dark-matter-punched holes in a small number of stellar streams hanging from globular clusters within the Milky Way.

From its position around 1 million miles (1.6 million kilometers) from Earth, Roman will be able to investigate such features in neighboring galaxies, particularly Andromeda, for the first time. Its wide-field instrument will produce images 200 times the size of those created by the Hubble Space Telescope.

To test this, this team simulated streams of stars and allowed them to interact with dark matter clumps, generating gaps as predicted. The scientists then created mock Roman observations of these dark matter-punched spaces in stellar streams. They concluded that Roman will indeed be capable of detecting these gaps when it opens its eyes to the cosmos at last.

Roman will shed more light on dark matter

The study of stellar streams hanging from globular clusters won't be the only dark matter hunt that Roman engages in as it studies the universe.

Scientists think that most, if not all, galaxies are enveloped in haloes of this mysterious matter. And these haloes are believed to extend far beyond the galaxies' visible matter contents. The latter will also be studied by the space telescope, named after NASA's first Chief of Astronomy Nancy Grace Roman, who is affectionately known as the "mother of Hubble."

Not only will Roman be used to investigate the dark matter halo around Andromeda, but it will also investigate the possible existence of smaller "sub-haloes" of dark matter around the nearby galaxy.

"We expect smaller dark matter sub-halos to interact with globular cluster streams," Starkenburg said. "If these sub-halos are present in other galaxies, we predict that we will see gaps in globular cluster streams that are likely caused by these sub-halos. 

"That will give us new information about dark matter, including which kinds of dark matter halos are present and what their masses are."

As well as being involved with this study, Starkenburg is already helping to lay the groundwork for Roman's dark matter detective work with the aid of funding through NASA's Nancy Grace Roman Space Telescope Research and Support Participation Opportunities program.

“That team plans to model how globular clusters form into stellar streams by developing a much more detailed theoretical framework,” she said. “We will go on to predict the origins of stream-forming globular clusters and whether these streams will be observable with Roman.”

The team's research is detailed in a preprint paper featured on the paper repository arXiv and has been accepted for publication in The Astrophysical Journal.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.

Robert Lea
Contributing Writer

Robert Lea is a science journalist in the U.K. whose articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space, Newsweek and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University. Follow him on Twitter @sciencef1rst.

  • Questioner
    Hypothesized DM really doesn't interact with light at all. DM doesn't reflect it, refract it block it or absorb it.

    "Dark matter does interact with gravity..."

    is kind of misleading.

    DM solely & exclusively creates gravity,
    but absolutely nowhere do we see DM responding to gravity. Not its own or any other gravity,
    which if you think about it is odd because gravity is the shape/geometry of space-time itself.
    DM is/would-be a one way gravity inducer,
    with no demonstrable inertia.

    The absolute and only evidence that might imply DM is behavior of visible matter with what appears to be gravity.

    "...we need extra mass to explain rotation."
    No, you need gravity as one possible means of explaining galaxies' rotations.

    DM forms into 'halos' that very neatly end up centering symmetrically on galactic centers,
    all happening with invisible 'dark physics' that have zero direct effects on any visible matter.

    The hypothesized quantity of DM in galaxies has an unexpected tight correlation with the specific sizes of each of their central black holes.
    ?

    Static clouds of gravitons or unknown expansive time dilation fields, possibly radiating from the central black hole of galaxies might be a better means of grappling with the observed effect, rather than leaping to invisible, virtually undetectable matter?

    Well, to each their own.
    Reply
  • Maxmeyes
    It seems dark matter is on par with big foot sightings. Those who believe will never be swayed by the lack of evidence in its existence. But as long as dark matter is a cash cow for research funding it will never go away.
    Reply
  • Adoni Yannop
    Questioner said:
    Hypothesized DM really doesn't interact with light at all. DM doesn't reflect it, refract it block it or absorb it.

    "Dark matter does interact with gravity..."

    is kind of misleading.

    DM solely & exclusively creates gravity,
    but absolutely nowhere do we see DM responding to gravity. Not its own or any other gravity,
    which if you think about it is odd because gravity is the shape/geometry of space-time itself.
    DM is/would-be a one way gravity inducer,
    with no demonstrable inertia.

    The absolute and only evidence that might imply DM is behavior of visible matter with what appears to be gravity.

    "...we need extra mass to explain rotation."
    No, you need gravity as one possible means of explaining galaxies' rotations.

    DM forms into 'halos' that very neatly end up centering symmetrically on galactic centers,
    all happening with invisible 'dark physics' that have zero direct effects on any visible matter.

    The hypothesized quantity of DM in galaxies has an unexpected tight correlation with the specific sizes of each of their central black holes.
    ?

    Static clouds of gravitons or unknown expansive time dilation fields, possibly radiating from the central black hole of galaxies might be a better means of grappling with the observed effect, rather than leaping to invisible, virtually undetectable matter?

    Well, to each their own.
    The 3 miliion physicists of the world and Questioner will never figure out what dark matter is until they come to understand that garvity generation and dark matter gravity generation are the direct function of mass and the rate at which the matter particles of the mass heat up!!

    The undeniable proof that gravity generation and dark matter gravity generation are the direct function of mass and the rate at which the matter particles of mass heat up is in the given facts below and my arguments of the given facts!!

    The Proofs About My Suggestion That Gravity Is The Direct Function Of Mass And The Rate At Which The Matter Particles Of The Mass Heat Up!!):
    1): Take Our Own Sun As An Example Of Gravity Generation As Our Sun’s Matter Heats Up!!):
    A): We Are Given That Our Sun Formed From The Collapse Of A Molecular Hydrogen-Helium Cloud At 10 Degrees Kelvin!!
    B): We Are Given That For The Past 5 Billion Years That Our Sun Has Been Heating Up And Generating Gravity!!
    C): We Are Given That Our Sun Will Heat Up By 6% Per Billion Years For The Next 5 Billion Years While Generating Gravity!!
    D): In 5 Billion Years); We Are Given That Our Sun Will Start Cooling From 7777 Kelvin To 3000 Kelvin While Net Emitting The Stored Anti-Gravity/Dark Energy Stored Inside The Nucleon, Electron And Neutrino Indestructible Mass-Energy Vessel Permeable Hovering Sacs In The Form Of Compressed GP1 Aether Particles That Were Stored During The 10 Billion Years That Our Sun Heated Up And Generated Gravity Blowing Off Half Its Mass Leaving A White Dwarf Remnant About The Size Of Earth At 200,000 Times Earth Density!!
    E): One Proof That As Matter Cools And Net Expels GP1 Aether Particles); Dark Energy Is Released Is The Red Giant Phase Of Our Sun’s Life Cycle And All Red Giant Stars!!
    2): From Observations Of Bullet Clusters We Know That Gravity And Dark Matter Gravity Stays With The Star Matter And Dark Neutrino Matter Heating Up From The Radiant Energy Of Stars And Not With An Equal Amount Of Cooling Hot Gaseous Matter Left Behind As The Two Galactic Clusters Separate!!
    Above 1 & 2): Coincidence Or Direct Proof That Gravity Is A Direct Function Of Mass And The Rate At Which The Matter Particles Of The Mass Heat Up And That As Matter Particles Cool And Net Expel GP1 Aether Particles); Dark Energy Is Released Like By The Cooling Hot Gases Equal To The Mass Of The Stars Of A Bullet Cluster And The Cooling Gases At 7777 Kelvin When Our Sun Will Begin To Transform To A Red Giant!!

    3): From The Discovery Of The DiPole RePeller Void In 2017): We Are Given That Lowering The Energy Quotient Per Cubic Meter In A Void Releases Measurable Dark Repulsive Energy As The Matter Including Dark Neutrino Matter In The Void Cools And Net Expels Compressed GP1 Aether Particles Creating A Void With Repulsive High GP1 Aether Particle Pressure System!!

    4): Suggestion): As Superclusters Crunch And Energy Density Per Cubic Meter Increases And As Nucleon Matter In All The Stars And Neutrino Dark Matter Heats Up By Net Compressing GP1 Aether Particles Inside The Matter Vessel Sacs While Reducing The Volume Of Space): We Generate Increasing Low GP1 Aether Particle Pressure Throughout The Supercluster As We Are Given That Gravity And Dark Matter Gravity Will Be Generated By The Reduction In GP1 Aether Particle Pressure Relative To The High GP1 Aether Particle Pressure Of Expanding Voids!!

    5): We Are Given That As The Great Attractor And The Shapley Attractor Crunch And Energy Density-Vacuum Energy Increases Per Cubic Meter); Matter Gravity And Dark Matter Gravity Is Generated In The Attractors That Causes The Local Galactic Group, The Virgo Galactic Centric Cluster And The Virgo Supercluster To Be Pulled At 341 Kilometers/Second Towards The Attractors); While The Cooling DiPole RePeller Void With Decreasing Vacuum Energy Per Cubic Meter Pushes Us At 290 Kilometers Per Second Towards The Great Attractor For A Net Total Peculiar Velocity Of 631 Kilometers/Second For Our Virgo Supercluster And Our Local Galactic Group!!

    6): We Are Given That Low Air Pressure Hurricane Systems Develop At The Equator And That Hurricanes Intensify From Solar Radiant Heat And Warm Water!!

    From The Given Above): I Suggest That The Heating Up Of Matter Particles Results In Low GP1 Aether Particle Pressure That Results In Low Air Pressure And/Or Gravitational Force Is Generated As Potential Dark Energy And Mass Is Stored In Matter Particle Permeable Sacs!!

    And At The Earth’s Poles We Are Given That As Matter Cools High Air Pressure Systems Develop As Compressed Net GP1 Aether Particles Pulsate Out Of Nucleon, Electron And Neutrino Pulsating Hovering Permeable Indestructible Vessel Sacs Resulting In High GP1 Aether Particle Systems That Transform Air Particles To High Air Pressure Systems As They Cool!!

    7): Side Note): If You Look At A Picture Of A Low Air Pressure Hurricane System On Earth And A Picture Of A Low GP1 Aether Particle Spiral Galaxy System In Space Side By Side); You Will Find The Pictures Are Nearly Identical Because Both Are Low GP1 Aether Particle Systems!!

    I welcome any and all questions about any and all of my posts, theories and associated proofs!! If you should question, you will learn about gravity, dark matter gravity and dark energy mysteries as given by modern physicists along with logical easy to understand physical mechanical explanations based on given facts!!

    Talk More Soon!! Have A Great Day!!!
    Reply
  • Adoni Yannop
    Maxmeyes said:
    It seems dark matter is on par with big foot sightings. Those who believe will never be swayed by the lack of evidence in its existence. But as long as dark matter is a cash cow for research funding it will never go away.
    Maxmeyes Said): “It seems dark matter is on par with big foot sightings!!”

    I say no!!): Dark matter gravity generation is real and proven over sixty years by, now, based on calculations of the velocity of stars orbiting a galaxy and the accurate calculations of the visible mass of the galaxy!!

    Astrophysicists have concluded that the stars of most or all galaxies have reached escape velocity and cannot be held in orbit around the galaxy without 5x the visible matter and associated gravity but because modern physicists do not understand that gravity can only be generated by matter particles with rest mass heating up, the physicists cannot fathom the fact that invisible neutrino permeable sacs heating up by net imploding Gaseous GP1 Aether Particles at about a quadrillionth the mass of the neutrino, reducing the volume of space and creating low GP1 Aether Particle pressure are the dark matter and the dark matter gravity generation mechanism scientists will search for millenniums to find until they come to understand the truth that I speak from the given facts in my previous post above!!

    Talk More Soon!! Have A Great Day!!
    Reply
  • ilovespace2024
    Maybe because Black Holes are made of dark matter
    Reply
  • ilovespace2024
    Adoni Yannop said:
    Maxmeyes Said): “It seems dark matter is on par with big foot sightings!!”

    I say no!!): Dark matter gravity generation is real and proven over sixty years by, now, based on calculations of the velocity of stars orbiting a galaxy and the accurate calculations of the visible mass of the galaxy!!

    Astrophysicists have concluded that the stars of most or all galaxies have reached escape velocity and cannot be held in orbit around the galaxy without 5x the visible matter and associated gravity but because modern physicists do not understand that gravity can only be generated by matter particles with rest mass heating up, the physicists cannot fathom the fact that invisible neutrino permeable sacs heating up by net imploding Gaseous GP1 Aether Particles at about a quadrillionth the mass of the neutrino, reducing the volume of space and creating low GP1 Aether Particle pressure are the dark matter and the dark matter gravity generation mechanism scientists will search for millenniums to find until they come to understand the truth that I speak from the given facts in my previous post above!!

    Talk More Soon!! Have A Great Day!!
    i agree
    Reply
  • Adoni Yannop
    Admin said:
    NASA's forthcoming Nancy Grace Roman Space Telescope will zoom in on streams of stars in the Andromeda galaxy to hunt for dark matter.

    Are gaps in the Andromeda galaxy filled with dark matter? This NASA telescope could find out : Read more
    More Proof That Gravity and Dark Matter Gravity are the direct function of mass and the rate at which the matter particles of the mass heat up!! Matter and dark neutrino matter with rest mass is being sucked into or orbiting M87 is compressed which causes the regular matter and the neutrino dark matter to heat up and generate a dark matter halo around M87 SMBH/Gravitational Lensing!!

    Published Paper): Black Hole Surrounded by a Dark Matter Halo in the M87 Galactic Center and its Identification with Shadow Images
    Kimet Jusufi, Mubasher Jamil, Paolo Salucci, Tao Zhu, Sumarna Haroon

    In this paper we present a new black hole solution surrounded by dark matter halo in the galactic center using the mass model of M87 and that coming from the Universal Rotation Curve (URC) dark matter profile representing family of spiral galaxies.
    In both cases the DM halo density is cored with a size r0 and a central density ρ0: ρ(r)=ρ0/(1+r/r0)(1+(r/r0)2). Since r0ρ0=120M⊙/pc2 , then by varying the central density one can reproduce the DM profile in any spiral. Using the Newman-Jains method we extend our solution to obtain a rotating black hole surrounded by dark matter halo. We find that, the apparent shape of the shadow beside the black hole spin a, it also depends on the central density of the surrounded dark matter ρ0. As a specific example we consider the galaxy M87, with a central density ρ0=6.9×106M⊙/kpc3 and a core radius r0=91.2 kpc. In the case of M87, our analyses show that the effect of dark matter on the size of the black hole shadow is almost negligible compared to the shadow size of the Kerr vacuum solution hence the angular diameter 42 μas remains almost unaltered when the dark matter is considered.

    For a small totally dark matter dominated spiral such as UGC 7232, we find similar effect of dark matter on the shadow images compared to the M87. However, in specific conditions having a core radius comparable to the black hole mass and dark matter with very high density, we show that the shadow images decreases compared to the Kerr vacuum black hole.

    The effect of dark matter on the apparent shadow shape can shed some light in future observations as an indirect way to detect dark matter using the shadow images.
    Comments):21 pages, 16 figures, references added. Version published in Physical Review D.
    Talk More Later!! Have A Great Day!!
    Reply
  • ilovespace2024
    Adoni Yannop said:
    More Proof That Gravity and Dark Matter Gravity are the direct function of mass and the rate at which the matter particles of the mass heat up!! Matter and dark neutrino matter with rest mass is being sucked into or orbiting M87 is compressed which causes the regular matter and the neutrino dark matter to heat up and generate a dark matter halo around M87 SMBH!!

    Published Paper): Black Hole Surrounded by a Dark Matter Halo in the M87 Galactic Center and its Identification with Shadow Images
    Kimet Jusufi, Mubasher Jamil, Paolo Salucci, Tao Zhu, Sumarna Haroon

    In this paper we present a new black hole solution surrounded by dark matter halo in the galactic center using the mass model of M87 and that coming from the Universal Rotation Curve (URC) dark matter profile representing family of spiral galaxies.
    In both cases the DM halo density is cored with a size r0 and a central density ρ0: ρ(r)=ρ0/(1+r/r0)(1+(r/r0)2). Since r0ρ0=120M⊙/pc2 , then by varying the central density one can reproduce the DM profile in any spiral. Using the Newman-Jains method we extend our solution to obtain a rotating black hole surrounded by dark matter halo. We find that, the apparent shape of the shadow beside the black hole spin a, it also depends on the central density of the surrounded dark matter ρ0. As a specific example we consider the galaxy M87, with a central density ρ0=6.9×106M⊙/kpc3 and a core radius r0=91.2 kpc. In the case of M87, our analyses show that the effect of dark matter on the size of the black hole shadow is almost negligible compared to the shadow size of the Kerr vacuum solution hence the angular diameter 42 μas remains almost unaltered when the dark matter is considered.

    For a small totally dark matter dominated spiral such as UGC 7232, we find similar effect of dark matter on the shadow images compared to the M87. However, in specific conditions having a core radius comparable to the black hole mass and dark matter with very high density, we show that the shadow images decreases compared to the Kerr vacuum black hole.

    The effect of dark matter on the apparent shadow shape can shed some light in future observations as an indirect way to detect dark matter using the shadow images.
    Comments):21 pages, 16 figures, references added. Version published in Physical Review D.
    Talk More Later!! Have A Great Day!!
    What about black holes?
    Reply