Astronomers have used a huge group of galaxies called the Phoenix cluster as a cosmic magnifying glass to detect X-ray emission from a very distant dwarf galaxy in its very first, high-energy stages of star formation. False-color and X-ray images of the giant arc in SPT-CLJ2344-4243: the X-ray-emitting giant arc is shown relative to the center of the foreground lensing galaxy cluster in a false-color image at optical wavelengths; the inset shows Chandra...
