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Satellite Galaxies

All articles tagged with #satellite galaxies

Faintest Galaxy Found Near Andromeda Defies Standard Formation Models
space13 days ago

Faintest Galaxy Found Near Andromeda Defies Standard Formation Models

Astronomers at the University of Michigan have identified Andromeda XXXV, the faintest and smallest satellite galaxy ever detected outside the Milky Way. Located near the Andromeda Galaxy (M31), this object contains only about 20,000 solar masses and hosts stars roughly 6 billion years old. Its existence challenges current theories, which suggest such low-mass galaxies should have ceased star formation long ago due to gas depletion or cosmic reheating. The discovery, confirmed via Hubble Space Telescope observations, suggests that larger neighbors may siphon gas from smaller galaxies, abruptly halting their evolution, and highlights gaps in our understanding of how dwarf galaxies survive in the local universe.

Astronomers spot 50 ghost dwarf satellites around three galaxies
space22 days ago

Astronomers spot 50 ghost dwarf satellites around three galaxies

Using deep VLT SMASH imaging around three distant galaxies (NGC 5068, 5084, 5087), astronomers identified about 50 faint satellite dwarf galaxies—47 candidates, with only four previously known—ranging from roughly 1 million to 1 billion solar masses and displaying diverse morphologies; the find helps address the cosmological missing-satellites problem and informs how dark matter shapes galaxy halos, with Euclid data expected to confirm them in future releases. The work by Crescenzo Tortora and colleagues was published Sept. 11 in Astronomy & Astrophysics.

Unraveling the Mysteries of Our Peculiar Galaxy
science1 year ago

Unraveling the Mysteries of Our Peculiar Galaxy

Recent research from the Satellites Around Galactic Analogs (SAGA) survey reveals that the Milky Way is unusual compared to similar galaxies, as it has fewer satellite galaxies, many of which have stopped forming stars. This anomaly suggests a unique evolutionary history for our galaxy, potentially linked to its dark matter halo. The findings challenge current models of galaxy formation and highlight the need to study a broader range of galaxies to understand these processes.

Milky Way: A Unique Outlier Among Galaxies, Survey Reveals
science1 year ago

Milky Way: A Unique Outlier Among Galaxies, Survey Reveals

Recent studies from the SAGA Survey reveal that the Milky Way is an outlier among similar-sized galaxies, with fewer satellite galaxies and unique star formation patterns. The research highlights the need to study a broader range of galaxies to better understand galaxy formation and the role of dark matter. The findings suggest that the Milky Way's evolutionary history is distinct, with its smaller satellites having ceased star formation, unlike those in other galaxies.

Counting the Galaxies Orbiting the Milky Way
science1 year ago

Counting the Galaxies Orbiting the Milky Way

The Milky Way galaxy has approximately 60 known satellite galaxies orbiting it within a distance of 1.4 million light-years, though this number is continually updated as new discoveries are made. These satellite galaxies, including the visible Large and Small Magellanic Clouds, are often faint and require advanced telescopes to detect. Over time, the Milky Way's gravitational pull may eventually consume these smaller galaxies, as it has done with others in the past.

"Satellite Galaxies' Motion Indicates a Younger Universe"
astronomy2 years ago

"Satellite Galaxies' Motion Indicates a Younger Universe"

Observations of the motion of satellite galaxies around massive galaxy groups suggest that the universe may be younger than predicted by the standard cosmological model with Planck cosmological parameters. Research using data from the Sloan Digital Sky Survey (SDSS) indicates a notable excess of correlated satellite pairs, implying that massive galaxy groups are younger in the real universe compared to current simulations. These findings challenge the existing cosmological model and may provide insights into the Hubble tension problem.

The Enormous Size of the Milky Way.
astronomy3 years ago

The Enormous Size of the Milky Way.

A recent study has summarized various methods to determine the mass of the Milky Way, including measuring the motion of stars, globular clusters, satellite galaxies, tidal plumes of dwarf galaxies, and stars leaving the galaxy. The team took a statistical average of these methods and determined the best value for the mass of the galaxy to be a trillion solar masses, give or take a few hundred billion solar masses. These methods rely on orbital motion and have varying levels of accuracy, but they all suggest that most of the galaxy's mass is in the form of dark matter.