Change the background colour to black. Duplicate the ‘Fragment’ layer and add a small outer glow to the bottom layer. Use Gaussian Blur (Filter > Blur > Gaussian Blur) on the top layer, setting the amount to 10, and set the blending mode to Linear Dodge. Next, grab a soft 50-pixel white brush with an opacity of 30%, and add dabs of glow to some of the fragments on the ground. Then use a large oval brush at 1,100 pixels, set the opacity to 15% and create the ground for the fragments.
Now it’s time to create the light burst coming from behind the obelisk. Create a new folder and name it ‘Background’, setting a new blank layer within it. Set your foreground colour to black, and the background to white, then select Filter > Render > Clouds. Apply Radial Blur to the render (Filter > Blur > Radial Blur), and set the amount to 100. Set the blur method to Zoom and the quality to Best. Apply this one more time by pressing Cmd/Ctrl + F. Bring up the Levels menu (Cmd/Ctrl + L) and enter the Input Level values 110; 1; 175.
Use the Polygonal Lasso tool (L) to select parts of the render. Add feather of 100 and delete the selection. Delete the bottom part of the burst with a large, soft eraser. This gives the burst a more random look.