Was the Andromeda Galaxy, the largest and most massive galaxy in our local neighborhood, shaped into its current structure due to a monstrous collision over 6 billion years ago? According to a new study by some French astronomers, the answer is oui.
They created a lovely animation based on the model. It shows the collision of the two galaxies and how they interact:
Wow! You can see how the galaxies get disrupted, and perhaps get something of a feel for just how violent and incredible an event on this scale can be.
Using a sophisticated computer code that models the gravitational and fluid (pedantic: hydrodynamical) interaction between stars, gas, dust, and dark matter, they found that an ancient and massive collision between a galaxy a bit bigger than our Milky Way, and a smaller one about 1/3 the mass, reproduces a large amount of the structure we see in Andromeda today. That includes "…the large thin disk including its giant ring of gas and dust, the massive central bulge, the gigantic thick disk, the giant stream of old stars, as well as many other stellar streams discovered in the galaxy halo" according to the press release (the paper itself is in French). (more…)
The Antennae Galaxies are probably the most famous and beautiful example of a cosmic traffic accident in the sky: two spiral galaxies undergoing a massive collision. Davide De Martin took the Hubble images of this pair and reprocessed them as part of his Sky Factory project:
Holy wow! These galaxies are very roughly 45 million light years away, which is relatively close. That means images from Hubble yield vast details. For example, the reddish-pink star-forming bursts, triggered by the collisions of huge dust and gas clouds, are obvious. Long streamers of visible-light-blocking dust can be seen, as well as many individual, massive and bright stars. The overall yellowish glow is from the collected light of tens of billions of stars like the Sun; too faint to be seen on their own, but adding up to provide the background for the more dynamic and dramatic goings-on. (more…)
Regular readers know I have an marginally unhealthy crush on Felicia Day. Of course, so do millions of other people, so she’s probably relatively safe from me.
Hey! That was funny! Like, really funny! Lots of inside jokes for Felicia’s fans, too ("Is this your first time doing an internet video, Miss Day?") A lot of times videos like this are just painful, but this one is actually really good. Felicia is great, and the Sean Astin stuff cracked me up.
And I think someone’s been reading my book… OK, probably not. But the way she talked about all the astronomy was very natural and smooth, so I just know deep in her heart Felicia’s harboring a strong and undeniable love for astronomer. I mean astronomy. Yes! Astronomy! Of course that’s what I meant!
Phil Plait, the creator of Bad Astronomy, is an astronomer, lecturer, and author. After ten years working on Hubble Space Telescope and six more working on astronomy education, he struck out on his own as a writer. He's written two books, dozens of magazine articles, and 12 bazillion blog articles. He is a skeptic and fights the abuse of science, but his true love is praising the wonders of real science.
The original BA site (with the Moon Hoax debunking, movie reviews, and all that) can be found here.
Contact me: The Bad Astronomer "at" gmail "dot" com
"If things worked the way I wanted them to, any reporter about to do another 'sensational' story on deadly meteors would consult this volume, and bang! common sense would find its way into the news. How strange would that world be?" -- Adam Savage, Mythbusters
"Reading this book is like getting punched in the face by Carl Sagan. Frightening, but oddly exhilarating." -- Daniel H. Wilson, author of How to Survive a Robot Uprising
