Filaments in the Tarantula Nebula
December 23, 2004
The marvelous richness of the filament colors in the Tarantula Nebula is due to the varying conditions in the interstellar gas in this region. The red in these images is caused by emission of excited hydrogen atoms, the green shades correspond to emission from oxygen atoms from which two electrons ("doubly-ionized oxygen") have been "knocked off" by the energetic radiation of hot stars in the R136 cluster, that is located beyond the lower right corner of this photo. The intensity of this emission increases towards R136, explaining the yellowish color near the edge of the photo. A blue color is contributed by singly-ionized atoms of oxygen. Other atoms like nitrogen and sulfur at different levels of ionization also add to the emission of the nebula at specific wavelengths. The observed colors thus probe the physical condition of the emitting gas and the temperature of the star(s) that excite(s) it. The intricate appearance of the filaments is mostly a consequence of turbulence in the interstellar gas, of the magnetic fields, and of the energy input by the massive stars in the neighborhood.
Topics: Environment, Astronomical spectroscopy, Large Magellanic Cloud, Dorado constellation, interstellar gas, Doubly ionized oxygen, R136, Pillars of Creation, Atom, Atomic physics, Chemistry, Interstellar medium, Emission nebula, Nebula