Related by context. Frequent words. (Click for all words.) 67 gamma rays 61 quasars 60 distant galaxies 59 supernovae 58 gamma ray burst 58 spectroscopic 58 infrared 57 gamma ray bursts 57 redshift 57 spectroscopy 57 quasar 57 cosmic rays 56 cosmic ray 56 gravitational waves 56 neutrino 56 gamma radiation 55 detector 55 X ray 55 cosmic microwave background 55 infrared radiation 54 galaxies 54 photon 54 wavelengths 54 pulsars 54 neutron star 54 neutrinos 53 spectrometer 53 electromagnetic 53 supernova 53 spectra 53 supermassive black holes 53 galaxy clusters 53 spectral 52 supermassive black hole 52 pulsar 52 infrared wavelengths 52 nebulae 52 photons 51 NASA Chandra 51 laser pulses 51 astronomers 51 magnetic fields 51 x ray 50 exoplanets 50 diffraction 50 terahertz 50 supernovas 50 laser pulse 50 extrasolar planets 50 exoplanet 50 Very Large Telescope 50 spectrometers 49 Spectroscopy 49 solar flares 49 Milky Way galaxy 49 THz 49 neutron 49 nebula 49 fluorescence 49 X ray Observatory 49 subatomic particles 49 neutrons 48 GRB 48 positrons 48 fainter 48 mass spectrometer 48 neutron stars 48 corona 48 detectors 48 electron 48 ultraviolet light 48 emitted 48 Milky Way 47 laser beams 47 particle 47 ultraviolet 47 luminosity 47 planet orbiting 47 microscopy 47 laser 47 Space Telescope 47 synchrotron 47 laser beam 47 electron beam 47 tomography 46 lasers 46 spatial resolution 46 galaxy 46 Spitzer Space Telescope 46 magnetosphere 46 imager 46 brown dwarfs 46 X ray imaging 46 wavelength 46 telescopes 46 optical 46 WMAP 46 adaptive optics 46 spectrograph 46 astrophysicists 46 NASA Cassini spacecraft