“The case of the missing dark matter”: Hubble solves a mystery



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Galaxy NGC1052-DF4

“The nature of dark matter is one of science’s greatest mysteries, and we need to use all the new related data to address it,” says astronomer Avi Loeb of the Harvard-Smithsonian Center for Astrophysics. Dark matter is “dark” in the sense that it hardly interacts with anything, particularly light. Although dark matter may be too elusive to be found in particle experiments, it can reveal its presence in astronomical observations.

On the edge of fundamental physics

Dark matter pushes the boundaries of the known fundamental laws of physics. Leading candidates for dark matter who have so far defied every type of detector designed to find it. Due to its huge gravitational footprint in space, we know that dark matter must make up about 85% of the total mass of the universe, but we don’t know what it’s made of yet, but if it has anything to do with scalar particles, it might being older than the Big Bang, physicists suggest, who, sounding like science fiction creators, have imagined new types of dark matter ranging from planet-sized particles to highly speculative dark matter life.

Hubble’s clues to missing dark matter

But what astrophysicists know, is that new data from the Hubble Space Telescope explains the reason for the lack of dark matter in NGC 1052-DF4, which resides 45 million light years from Earth. Astronomers have found that the missing enigmatic matter can be explained by the effects of the disruption of the tides from the gravity forces of the nearby massive galaxy NGC 1035 which are robbing NGC 1052-DF4 of dark matter. while the stars feel the effects of interacting with another galaxy at a later stage.

“Is the dark matter signal from the universe buried in the space telescope data from 20 years ago?”

Until now, the removal of dark matter in this way has remained hidden until astronomers using Hubble’s high resolution have been able to observe extremely deep images that can reveal extremely faint features, including identifying the population of globular clusters. of the galaxy.

“We used Hubble in two ways to find that NGC 1052-DF4 is experiencing an interaction, this includes studying the galaxy’s light and the galaxy’s distribution of globular clusters,” explained STScI Fellow at the Space Telescope Science Institute, Mireia. Montes of the University of New South Wales in Australia, who led an international team of astronomers to study the galaxy using deep optical images including the 10.4-meter Gran Telescopio Canarias (GTC) telescope and the IAC80 telescope in the Canary Islands, in Spain, to complete the Hubble observations,

Strange lightness of dark matter – “Might be older than the Big Bang”

This image at the top of the page shows the region around the galaxy NGC 1052-DF4, taken by the IAC80 telescope at the Teide Observatory in Tenerife. The figure highlights the main galaxies in the field of view, including NGC 1052-DF4 (center of image) and its neighbor NGC 1035 (center left).

Globular clusters reveal clues

Globular clusters: The oldest visible objects in the universe that are thought to have formed just after the Universe began nearly 13.8 billion years ago, at the same time or perhaps even before the first galaxies formed. They are thought to form in the episodes of intense star formation that shaped galaxies. Each contains hundreds of thousands to occasionally over ten million stars all born at essentially the same time and densely packed into a spherical volume more than a thousand times smaller in diameter than the Milky Way’s diameter. Their compact size and brightness make them easily observable and are therefore good tracers of the properties of the galaxy that hosts them.

“Oldest Objects in the Universe” – Hubble Clues Solves the puzzle of globular galaxy clusters

By studying and characterizing the spatial distribution of clusters in NGC 1052-DF4, astronomers can develop information on the current state of the galaxy itself. The alignment of these clusters suggests that they have been “stripped” of the host galaxy, and this supports the conclusion that a tidal outage is occurring.

The tide queues confirm a disturbance event

By studying the galaxy’s light, the astronomers also found evidence of tidal tails, which are formed from material moving away from NGC1052-DF4 – this further supports the conclusion that it is a disturbing event. Further analysis concluded that the central parts of the galaxy remain intact and only 7% of the galaxy’s stellar mass is housed in these tidal tails. This means that dark matter, which is less concentrated than stars, was previously and preferentially stripped from the galaxy, and now the outer stellar component is also starting to be stripped.

Secret of Dark Matter – “Enormous Beacon and Planet-Sized Particles”

Stars showing effects after evaporation of dark matter

“This result is a good indicator that, while the galaxy’s dark matter has evaporated from the system, the stars are only now starting to suffer the interruption mechanism,” explained team member Ignacio Trujillo of the Instituto de Astrofísica de Canarias in Spain. “Over time, NGC1052-DF4 will be cannibalized by the great system around NGC1035, with at least some of their stars floating free in deep space.”

“A sigh of relief”

The discovery of evidence supporting the tidal disruption mechanism as an explanation for the galaxy’s missing dark matter not only solved an astronomical conundrum, but also brought astronomers a sigh of relief. Without it, scientists would be faced with having to revise our understanding of the laws of gravity.

“This discovery reconciles existing knowledge of how galaxies form and evolve with the more favorable cosmological model,” added Montes.

The Daily Galaxy, Max Goldberg, via ESA / Hubble Information Center



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