Chandra Release - January 10, 2006

Visual Description: NGC 0507

The series of separate X-ray and optical images of 6 elliptical galaxies shows a series of blue-white (X-ray) and grey-white (optical) extended sources arranged in a 4 by 3 grid.  Chandra images of a survey of elliptical galaxies have revealed evidence for unsuspected turmoil. As this sample gallery of X-ray and optical images shows, the shapes of the massive clouds of hot gas that produce X-ray light in these galaxies differ markedly from the distribution of stars that produce the optical light. The leftmost three X-ray images are mostly irregular sphere shapes, with the rightmost three X-ray images having almost shell-like and textured structures.  The three optical images on the left are like cotton balls, and the ones on the right have smaller central point sources in the top 2 rows, with a medium sized source in the lower right.  Except for rare cases, most violent activity in isolated elliptical galaxies was thought to have stopped long ago. Elliptical galaxies contain very little cool gas and dust, and far fewer massive young stars which explode as supernovas. Thus it was expected that the hot interstellar gas would have settled into an equilibrium shape similar to, but rounder than that of the stars.