Chandra's telescopes picked up the heat before anything else; that cloud of superheated gas is around six million degrees Fahrenheit, so "superheated" is, if anything, an understatement. Then scientists began putting the puzzle pieces together. The gas formed a comet-like shape, indicating the motion of the dwarf galaxy as it collided with the larger spiral galaxy. The spiral galaxy is about 60 million light-years from Earth, named NGC 1232, as these things are. At the head of that comet-ish shape are a bunch of very bright points and strong x-ray emission. NASA thinks that's the creation of super-powerful stars, triggered by the collision.