Related by context. Frequent words. (Click for all words.) 72 gravitational lensing 62 magnetar 62 galaxy cluster 62 interferometry 61 photonic crystal 61 X ray emission 61 redshift 60 XMM Newton 60 celestial object 60 gamma ray burst 60 distant galaxy 59 infrared wavelengths 58 galaxy clusters 58 Crab Nebula 58 supernova remnant 58 Earth magnetosphere 58 GRBs 58 spectroscopic 58 anisotropy 57 ESO Very Large Telescope 57 cosmic ray 57 diffraction 57 gravitational wave 57 quasar 57 Very Large Telescope 57 gravitational waves 57 parallax 57 occultation 57 spacetime 57 infrared radiation 57 adaptive optics 56 magnetic fields 56 excitons 56 optical microscope 56 astronomical observations 56 confocal microscopy 56 auroral 56 electron beams 56 distant galaxies 56 gravitational tug 55 photonic crystals 55 galaxy formation 55 quasars 55 NASA Cassini spacecraft 55 brown dwarf 55 metamaterial 55 Eta Carinae 55 HD #b [002] 55 unaided eye 55 WIMPs 55 neutrino 55 X ray Observatory 55 supernova explosion 55 elliptical galaxies 55 NASA Chandra 55 Raman spectroscopy 55 neutrinos 54 astronomical objects 54 gamma ray bursts 54 gamma rays 54 accretion disk 54 muon 54 scanning tunneling microscope 54 phonons 54 Fomalhaut 54 Spitzer Space Telescope 54 brown dwarfs 54 planet orbiting 54 dwarf galaxy 54 optical telescopes 54 astronomers 54 waveguides 54 COROT 54 extrasolar planets 54 magnification 54 dynamical 54 reflectance 54 cosmic microwave background 54 plasmonic 54 Iapetus 53 geomagnetic storms 53 Orion Nebula 53 cosmic rays 53 extrasolar planet 53 Saturn rings 53 magnetosphere 53 substorms 53 Andromeda Galaxy 53 Gliese #g 53 X ray beam 53 anisotropic 53 Kuiper belt 53 Andromeda galaxy 53 FRET 53 superposition 53 heliosphere 53 photons 53 Brownian motion 53 magnetization 53 neutron star 53 synchrotron radiation