Tuesday, March 03, 2009

A galaxy that isn't supposed to be there

Conventional wisdom suggests dark matter is a pre-requisite for galaxy formation, but a set of dwarf galaxies detected in the constellation Leo appear to be without dark matter. (Cosmos) From what we understand, matter is supposed to coalesce around 

dark matter forming galaxies, like dew drops on a spider web.  From there, dark matter represents the missing mass that holds galaxies together (from what we can tell, galaxies aren't heavy enough to hold themselves together… they should spin apart). 

Alas, the dark matter-less galaxies were there, detected by NASA's Galaxy Evolution Explorer spacecraft (GALEX). So how did they get there?  One theory, the "gravitational influence" of a nearby galaxy.  Another theory, we're looking at a "previously-undiscovered method of galaxy formation." 

According to Cal Tech press release, the strange dwarves may have "formed out of nothing more than pristine gas likely leftover from the early universe." Here's an image of the galaxies from the release… 

(image NASA/JPL)

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I started pound360 to channel my obsession with vitamins, running and the five senses. Eventually, I got bored focusing on all that stuff, so I came back from a one month hiatus in May of 2007 (one year after launching Pound360) and broadened my mumblings here to include all science.