Quasar ghosts!
The ethereal wisps in these images were illuminated, perhaps briefly, by a blast of radiation from a quasar — a very luminous and compact region that surrounds a supermassive black hole at the centre of a galaxy. Galactic material falls inwards towards the central black hole, growing hotter and hotter, forming a bright and brilliant quasar with powerful jets of particles and energy beaming above and below the disc of infalling matter… The first object of this type was found in 2007 by Dutch schoolteacher Hanny van Arkel (heic1102). She discovered the ghostly structure in the online Galaxy Zoo project, a project enlisting the help of the public to classify more than a million galaxies catalogued in the Sloan Digital Sky Survey (SDSS). The bizarre feature was dubbed Hanny’s Voorwerp (Dutch for Hanny’s object).More on this at HubbleSite
Image credits: NASA, ESA, Galaxy Zoo Team and W. Keel (University of Alabama, USA)