Space Telescope Science
In 2007, Dutch schoolteacher Hanny van Arkel discovered a never-before-seen ghostly structure near a galaxy, while she was participating in an online amateur scientist project called Galaxy Zoo. The galaxy hosts a bright quasar that may have illuminated the apparition by hitting it with a beam of light from hot gas around a central black hole. Astronomers eagerly used the Hubble Space Telescope to do follow-up observations, which revealed knots of dust and gas in the "greenish blob." Assuming that this feature could offer insights into the puzzling behavior of active galaxies, Bill Keel of the University of Alabama, Tuscaloosa, initiated a search for other similar phenomenon. After all, where there's one strange blob there could be more. Keel had 200 volunteers look at archival data of 15,000 galaxies hosting quasars. In the end, he found eight other galaxies with bright active nuclei that have illuminated material far outside the radius of the galaxy. The eerie structures have looping, spiral, and braided shapes. Hubble's images show that they are like the remnants of galaxy collisions.
Join Hubble scientists for a live Hubble Hangout discussion at 3pm EDT on Thurs., April 2, to learn even more. Visit: http://hbbl.us/y6c .