In astronomy they are valuable for studying high - energy objects or regions , however as with X-rays this can only be done with telescopes outside the Earth 's atmosphere .
These are the most energetic photons , having no defined lower limit to their wavelength .
In astronomy photons are valuable for studying high - energy objects or regions , however as with X-rays this can only be done with telescopes outside the Earth 's atmosphere .
These are the most energetic photons , having no defined lower limit to their wavelength .