Milky Way tagged posts

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 ...

Read More

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 ...

Read More

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...

Read More

Gaia starts Mapping the Galactic Bar in the Milky Way

This colour chart, superimposed on an artistic representation of the galaxy, shows the distribution of 150 million stars in the Milky Way probed using data from the second release of ESA’s Gaia mission in combination with infrared and optical surveys, with orange/yellow hues indicating greater density of stars. Most of these stars are red giants. While the majority of charted stars are located closer to the Sun (the larger orange/yellow blob in the lower part of the image), a large and elongated feature populated by many stars is also visible in the central region of the galaxy: this is the first geometric indication of the galactic bar. Credit: ESA/Gaia/DPAC, A. Khalatyan (AIP) & StarHorse Team; mapa artístic de la Galaxia: NASA/JPL-Caltech/R. Hurt (SSC/Caltech)

The first direct ...

Read More