Instantiate objects along a ray in four directions

I would like to instantiate my explosion effect (particle system) along a ray from a bomb.

Now I just draw a lines in 4 directions:

     Vector3 forward = transform.TransformDirection(Vector3.forward) * explosionRange;
     Vector3 back = transform.TransformDirection(Vector3.back) * explosionRange;
     Vector3 left = transform.TransformDirection(Vector3.left) * explosionRange;
     Vector3 right = transform.TransformDirection(Vector3.right) * explosionRange;

     Debug.DrawRay(transform.position, forward, Color.red, 1f);
     Debug.DrawRay(transform.position, back, Color.red, 1f);
     Debug.DrawRay(transform.position, left, Color.red, 1f);
     Debug.DrawRay(transform.position, right, Color.red, 1f);

I attached my particle system gameobject to the script, but what is the best way to instantiate these objects along these four rays?