Print this page

Mysterious ripples in the Milky Way were caused by a passing dwarf galaxy

Written by  Sunday, 25 September 2022 17:32
Write a comment
Lund, Sweden (SPX) Sep 25, 2022
Using data from the Gaia space telescope, a team led by researchers at Lund University in Sweden has shown that large parts of the Milky Way's outer disk vibrate. The ripples are caused by a dwarf galaxy, now seen in the constellation Sagittarius, that shook our galaxy as it passed by hundreds of millions of years ago. Our cosmic home, the Milky Way, contains between 100 and 400 billion st

Using data from the Gaia space telescope, a team led by researchers at Lund University in Sweden has shown that large parts of the Milky Way's outer disk vibrate. The ripples are caused by a dwarf galaxy, now seen in the constellation Sagittarius, that shook our galaxy as it passed by hundreds of millions of years ago.

Our cosmic home, the Milky Way, contains between 100 and 400 billion stars. Astronomers believe that the galaxy was born 13.6 billion years ago, emerging from a rotating cloud of gas composed of hydrogen and helium. Over billions of years, the gas then collected in a rotating disk where the stars, such as our sun, were formed.

In a new study published in Monthly Notices of the Royal Astronomical Society, the research team presents their findings about the stars in the outer regions of the galactic disk.

"We can see that these stars wobble and move up and down at different speeds. When the dwarf galaxy Sagittarius passed the Milky Way, it created wave motions in our galaxy, a little bit like when a stone is dropped into a pond", Paul McMillan, the astronomy researcher at Lund Observatory who led the study, explains.

By using data from the European space telescope Gaia, the research team was able to study a much larger area of ??the Milky Way's disk than was previously possible. By measuring how strong the ripples are in different parts of the disc, the researchers have begun to piece together a complex puzzle, providing clues about Sagittarius' history and orbit around our home galaxy.

"At the moment, Sagittarius is slowly being torn apart, but 1-2 billion years ago it was significantly larger, probably around 20 percent of the mass of the Milky Way's disk", says Paul McMillan.

The researchers were surprised by how much of the Milky Way they could study using the data from Gaia. To date the telescope, which has been in operation since 2013, has measured the movement across the sky of approximately two billion stars and the movement towards or away from us of 33 million.

"With this new discovery, we can study the Milky Way in the same way that geologists draw conclusions about the structure of the Earth from the seismic waves that travel through it. This type of "galactic seismology" will teach us a lot about our home galaxy and its evolution", Paul McMillan concludes.

Research Report:The disturbed outer Milky Way disc


Related Links
Lund University
Stellar Chemistry, The Universe And All Within It

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

SpaceDaily Contributor
$5 Billed Once

credit card or paypal



STELLAR CHEMISTRY
Is over-eating to blame for bulges in Milky Way bar
Tokyo, Japan (SPX) Sep 12, 2022
A new simulation conducted on the world's most powerful supercomputer dedicated to astronomy has produced a testable scenario to explain the appearance of the bar of the Milky Way. Comparing this scenario to data from current and future space telescopes will help clarify the evolution of our home Galaxy. Astronomy is revealing the structure of the Milky Way Galaxy in which we live in increasing detail. We know that it is a disk galaxy, with two- or four- armed spirals, with a straight bar in the m ... read more


Read more from original source...

You must login to post a comment.
Loading comment... The comment will be refreshed after 00:00.

Be the first to comment.