Evidence for the Presence of Dark Matter in the Innermost Part of the Milky Way

The rotation curve tracers used in the paper over a photo of the disc of the Milky Way as seen from the Southern Hemisphere. The tracers are color-coded in blue or red according to their relative motion with respect to the Sun. The spherically symmetric blue halo illustrates the dark matter distribution.

A new study from astrophysicists at Stockholm University provides evidence for the presence of dark matter in the innermost part of the Milky Way, including in our own cosmic neighborhood and the Earth’s location.

The study demonstrates that large amounts of dark matter exist around us, and also between us and the Galactic center. The result constitutes a fundamental step forward in the quest for the nature of dark matter.

The existence of dark matter in the outer parts of the Milky Way is well established. But historically it has proven very difficult to establish the presence of dark matter in the innermost regions, where the Solar System is located. This is due to the difficulty of measuring the rotation of gas and stars with the needed precision from our own position in the Milky Way.

“In our new study, we obtained for the first time a direct observational proof of the presence of dark matter in the innermost part of the Milky Way. We have created the most complete compilation so far of published measurements of the motion of gas and stars in the Milky Way, and compared the measured rotation speed with that expected under the assumption that only luminous matter exists in the Galaxy. The observed rotation cannot be explained unless large amounts of dark matter exist around us, and between us and the Galactic center”, says Miguel Pato at the Department of Physics, Stockholm University.

Dark matter is about five times more abundant than the matter that we are familiar with, made of atoms. Its existence in galaxies was robustly established in the 1970s with a variety of techniques, including the measurement of the rotation speed of gas and stars, which provides a way to effectively “weigh” the host galaxy and determine its total mass.

“Our method will allow for upcoming astronomical observations to measure the distribution of dark matter in our Galaxy with unprecedented precision. This will permit to refine our understanding of the structure and evolution of our Galaxy, and it will trigger more robust predictions for the many experiments worldwide that search for dark matter particles. The study therefore constitutes a fundamental step forward in the quest for the nature of dark matter”, says Miguel Pato.

Publication: Fabio Iocco, et al., “Evidence for dark matter in the inner Milky Way,” Nature Physics (2015); doi:10.1038/nphys3237

Image: Serge Brunier

AstronomyAstrophysicsDark MatterPopularStockholm University
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  • Colin Bradshaw

    Of course you could instead explain these anomalous rotations with the realization that; if you take the observation that the luminous masses rotational vectors are instead a result of a force addition instead of a mass addition, you broach the controversial idea that electrostatic forces and electromagnetic coupling along the arms of galaxies could induce the cohesive chain of force required for faster rotation than gravitational forces alone could allow for. Scientists have already measured the power output of ‘black holes’ polar jets and can infer there magnetic strength from this. By measuring Sag A’s magnetic strength we could get an approximation of the induced electrical current of our galactic center, and test how much force this could potentially produce. We could then see if this could explain observed rotational velocities by substituting mass for force. A falsifiable experiment that could help make some sense from the results that this experiment concludes (we are missing something from our theories/observations).

  • mpc755

    There is evidence of dark matter every time a double slit experiment is performed; it’s what waves.

    Dark matter has mass. Dark matter physically occupies three dimensional space. Dark matter is physically displaced by the particles of matter which exist in it and move through it.

    The Milky Way’s halo is not a clump of dark matter anchored to the Milky Way. The Milky Way is moving through and displacing the dark matter.

    The Milky Way’s halo is the state of displacement of the dark matter.

    The Milky Way’s halo is the deformation of spacetime.

    What is referred to geometrically as the deformation of spacetime physically exists in nature as the state of displacement of the dark matter.

    A moving particle has an associated dark matter displacement wave. In a double slit experiment the particle travels through a single slit and the associated wave in the dark matter passes through both.

    Q. Why is the particle always detected traveling through a single slit in a double slit experiment?
    A. The particle always travels through a single slit. It is the associated wave in the dark matter which passes through both.

    What ripples when galaxy clusters collide is what waves in a double slit experiment; the dark matter.

    Einstein’s gravitational wave is de Broglie’s wave of wave-particle duality; both are waves in the dark matter.

    Dark matter displaced by matter relates general relativity and quantum mechanics.