The Milky Way could be surrounded by an invisible army

For decades, astronomers know that the Milky Way is not alone in space. For example. However, Around our galaxy already revolve around sixty small satellite galaxies, compact and weakly bright objects, often qualified as dwarf galaxies. However. Furthermore. if we believe a new study by cosmologists from the University of Durham, there would be much more, perhaps more than a hundred, who still remain invisible to our instruments.

These missing galaxies are not simply a curiosity for astronomers: their potential existence fuels a fundamental debate in cosmology. Similarly, It could make it possible to consolidate. In addition. or to question, the dominant model which describes the structure of the universe and the formation of galaxies, known as the Lambda-CDM model (Lambda cold black matter).

The mystery of the missing satellite galaxies – Milky way could surrounded invisible new

The Lambda-CDM model predicts that all the milky way could surrounded invisible galaxies. Similarly, large or small, are formed within gigantic invisible bubbles called black matter halos. Nevertheless, This dark matter, although unobservable directly, would constitute around 85 % of the material of the universe. Meanwhile, It does not reflect. Consequently, emits light, but its existence is deduced from its gravitational effects on galaxies, stars and light itself.

Around the Milky Way. Consequently, this halo of dark matter acts as a gravitational net, capturing over the ages of countless dwarf galaxies. However, at present, only a few tens of these satellites have been identified. Meanwhile, According to simulations of the Lambda-CDM model, there should be much more. This inconsistency is known to astrophysicists as the problem of missing satellites.

Is it a model of the model, or a simple observation bias? This is precisely this question that milky way could surrounded invisible new Durham researchers wanted to explore.

A dive into the galactic halo with milky way could surrounded invisible supercomputers – Milky way could surrounded invisible new

To try to see more clearly. scientists relied on one of the most precise and detailed simulations ever made: the aquarius simulation. This computer model reproduces with extreme finesse the distribution of dark matter in a galactic halo similar to that. of the Milky Way.

They joined the Galform code there. a modeling tool which simulates the formation of galaxies by following essential parameters such as the cooling of gas. the appearance of the first stars or the progressive aggregation of matter.

Thanks to this approach, they were able to reconstruct the eventful history of potential satellite galaxies. Their results are final: there would indeed be between 80. more than 100 additional dwarf galaxies in orbit around our Milky Way. If they escape our telescopes today. it is milky way could surrounded invisible new not that they do not exist, but rather that they have become almost invisible over time.

These galaxies which dissolve slowly

In billions of years. these small dwarf galaxies have multiplied many times the gravitational halo of the Milky Way. With each passage, they lost part of their material, torn off by the gravitational forces of our galaxy. Little by little, their stars content has diminished, as is their black matter halo. Some have been almost entirely absorbed, others barely remain, reduced to islets of stars at the limit of detection.

It is precisely this extreme light weakness that makes milky way could surrounded invisible new their observation so difficult. The milky way could surrounded invisible current instruments are struggling to identify these ghostly galaxies. disseminated in the immensity of our galactic halo.

The future of observations: lift the veil on the invisible

But this situation could change very soon thanks to technological progress. The Vera Rubin observatory. equipped with the largest digital camera ever built for astronomy, could well lift the veil on these hidden satellites. Thanks to its exceptional abilities to identify weakly luminous objects, it should be able to confirm or deny these predictions.

For cosmologists, the issue is considerable. Such a discovery would validate the Lambda-CDM model. strengthen the confidence of scientists in their understanding of the major structures of the universe. As Carlos Frenk points out. co-author of the study. this confirmation would be “a remarkable success for theory” and would show “how much math, physics and the milky way could surrounded invisible new power of superordinators can predict still invisible phenomena”.

A milky way could surrounded invisible reminder of the current limits of our gaze on the universe

Basically. this research highlights an often forgotten reality: our vision of the universe is still very partial. What we observe today is only a tiny fraction of what really exists. In the coming years, new discoveries will certainly complement this painting.

Because if these hidden satellite galaxies do exist, they are not just points of light on our sky cards. They are precious witnesses to the tumultuous history of our galaxy. and essential keys to better understand the invisible architecture that shapes the universe.