Illustris Freeze Frame (image) Harvard-Smithsonian Center for Astrophysics Caption This still frame from the Illustris simulation is centered on the most massive galaxy cluster existing today. The blue-purple filaments show the location of dark matter, which attracts normal matter gravitationally and helps galaxies and clusters to clump together. Bubbles of red, orange and white show where gas is being blasted outward by supernovae or jets from supermassive black holes. Credit Illustris Collaboration Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.