WISE Beholds a Pair of Dancing Galaxies

[n2doc]

This image from NASA's Wide-Field Infrared Survey Explorer, or WISE, features two stunning galaxies engaged in an intergalactic dance. The galaxies, Messier 81 and Messier 82, swept by each other a few hundred million years ago, and will likely continue to twirl around each other multiple times before eventually merging into a single galaxy. The relatively recent encounter triggered a spectacular burst of star formation visible in both galaxies.

Messier 81 (bottom of image) is a prototypical "grand design" spiral galaxy with its pronounced and well-defined arms spiraling into its core. At the wavelengths WISE sees, these beautiful arms show areas of compressed interstellar gas and dust, which go hand-in-hand with areas of increased star formation. The spiral density waves that create this compression and star formation have been enhanced by the close gravitational interaction with its partner galaxy, Messier 82, causing the arms to appear more prominent than what is typically seen in other isolated spiral galaxies.

Messier 82 (top of image) is also a spiral galaxy. However, it is seen edge-on from our point of view. It was originally classified as an irregular galaxy, until 2005, when astronomers were able to tease out spiral structure in near-infrared images (similar to wavelengths that WISE sees). Viewed in visible wavelengths, this galaxy appears to have a long thin bar shape, hence its common name, the Cigar Galaxy.

Messier 82 is also a starburst galaxy, meaning it is currently forming stars at an exceptionally high rate. This huge burst of activity was caused by its close encounter with Messier 81, whose gravitational influence caused gas near the center of Messier 82 to rapidly compress. This compression triggered an explosion of star formation, concentrated near the core. The intense radiation from all of the newly formed massive stars creates a galactic "superwind" that is blowing massive amounts of gas and dust out perpendicular to the plane of the galaxy. This ejected material (seen as the orange/yellow areas extending up and down) is made mostly of polycyclic aromatic hydrocarbons, which are common products of combustion here on Earth. It can literally be thought of as the smoke from the cigar.

more

http://www.nasa.gov/mission_pages/WISE/multimedia/gallery/pia13454.html

[LiberalEsto]

1. Maybe they're mating? nt

[Peace Patriot]

2. They're smoking "polycyclic aromatic hydrocarbons" out there? Is that legal?

Some day, when Earth becomes civilized, some anthropologist on Arcturus is going to use the phrase "Dark Ages" to describe this period in our history, where it's okay to slaughter a hundred thousand innocent people to steal their oil but growing a weed gets you 15 years crammed into an overcrowded dungeon--where you may well get raped and beaten or even killed, where the food is not fit for dogs, and where you are treated like a subhuman and forgotten by the rest of society--confiscation of your property, destruction of your family, permanently banned from most jobs, permanently ineligible for government scholarships and many other benefits, and your citizenship is basically revoked including loss of your right to vote.

Why did this OP inspire this rant? I don't know. Maybe looking at the stars, and looking at ourselves from the point of view of billions of years of cosmic life, puts things into perspective. Make a joke. See the light.