Milky Way tagged posts

Astronomers discover New ‘Fossil Galaxy’ Buried Deep within the Milky Way

An all-sky image of the stars in the Milky Way as seen from Earth. The coloured rings show the approximate extent of the stars that came from the fossil galaxy known as Heracles. Credit: Danny Horta-Darrington (LJMU), ESA/Gaia, SDSS

Scientists working with data from the Sloan Digital Sky Surveys’ Apache Point Observatory Galactic Evolution Experiment (APOGEE) have discovered a “fossil galaxy” hidden in the depths of our own Milky Way. This result, published in Monthly Notices of the Royal Astronomical Society, may shake up our understanding of how the Milky Way grew into the galaxy we see today.

The proposed fossil galaxy may have collided with the Milky Way ten billion years ago, when our galaxy was still in its infancy...

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Evidence of Broadside Collision with Dwarf Galaxy discovered in Milky Way

The Milky Way’s Shell Structure Reveals the Time of a Radial Collision
Thomas Donlon II, Heidi Jo Newberg, Robyn Sanderson, Lawrence M. Widrow

‘Shell structures’ are first of their kind found in the galaxy. Nearly 3 billion years ago, a dwarf galaxy plunged into the center of the Milky Way and was ripped apart by the gravitational forces of the collision. Astrophysicists announced today that the merger produced a series of telltale shell-like formations of stars in the vicinity of the Virgo constellation, the first such “shell structures” to be found in the Milky Way. The finding offers further evidence of the ancient event, and new possible explanations for other phenomena in the galaxy.

Astronomers identified an unusually high density of stars called the Virgo Overdensity about ...

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Milky Way could be Catapulting Stars into its Outer Halo

Milky Way could be catapulting stars into its outer halo, UCI astronomers say
A simulated galaxy image from the FIRE-2 project, representing a structure spanning more than 200,000 light years, shows the prominent plumes of young blue stars born in gas that was originally rotating and then blown radially outward by supernova explosions. Courtesy of Sijie Yu / UCI

Findings may change fundamental thinking about star system formation, dynamics. University of California, Irvine astronomers and others have shown that clusters of supernovas can cause the birth of scattered, eccentrically orbiting suns in outer stellar halos, upending commonly held notions of how star systems have formed and evolved over billions of years.

Hyper-realistic, cosmologically self-consistent computer simulations from the Feedback in Realistic Environments 2 project enabled the scientists ...

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XMM-Newton discovers Scorching Gas in Milky Way’s Halo

Milky Way halo – artist’s impression

ESA’s XMM-Newton has discovered that gas lurking within the Milky Way’s halo reaches far hotter temperatures than previously thought and has a different chemical make-up than predicted, challenging our understanding of our galactic home.

A halo is a vast region of gas, stars and invisible dark matter surrounding a galaxy. It is a key component of a galaxy, connecting it to wider intergalactic space, and is thus thought to play an important role in galactic evolution.

Until now, a galaxy’s halo was thought to contain hot gas at a single temperature, with the exact temperature of this gas dependent on the mass of the galaxy.

However, a new study using ESA’s XMM-Newton X-ray space observatory now shows that the Milky Way’s halo contains no...

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