Chandra Release - October 16, 2017

Visual Description: GW170817

This graphic features the gravitational wave source GW170817 from the merger of two neutron stars features a galaxy in the center, with two insets to the upper right. The main image shows this distant galaxy (NGC 4993) glowing in optical light. The galaxy appears to have a cloudy, milky texture. Overlaid on the galaxy is a small box, and inside the box is a little, point-like spot. X-ray emission detected by Chandra some days after the neutron stars merged. This spot is shown in the inset boxes in purple. The dates of the two Chandra observations are August 19th and 26th, 2017. Initially the X-rays were undetected (first box), but as time passed the spot brightened (2nd box, a large purple dot), indicating an afterglow from a relativistic jet viewed off-axis.