NGC 2070 is one of the more famous emission nebula not listed in the Messier catalog. Most professional astronomers refer to the nebula by yet another name, 30 Doradus. The nebula is found in the Large Magellanic Cloud (LMC), a nearby neighbor galaxy to the Milky Way. Because of its location, NGC 2070 (and the LMC) is visible primarily from the Southern Hemisphere. Each of the images in this gallery are about half the diameter of a full moon.
Visible: DSS, Visible: Color,
The visible-light images (above) vividly show the complex distribution of the illuminated gas within the nebula. The primary sources of illumination are hot and young blue supergiant stars buried within the central core of the nebula. The Tarantula is a splendid example of an H-II region , where hydrogen gas is ionized (i.e., it loses an electron) by visible-light and ultraviolet photons from the embedded bright stars. For a close-up view of the inner regions of NGC 2070 obtained by visible-light and near-infrared cameras aboard the Hubble Space Telescope click here. Note that this HST photo covers the central 1/5th of the field of view adopted in this gallery.
Near-Infrared: 2MASS and Near/Mid-Infrared Composite: Spitzer
The near-infrared view of NGC 2070 obtained by 2MASS (above) is generally similar to the visible-light views. There are important differences, however. First the extent of illuminated gas is less. Second, we are able to see deeper into the central regions of the nebula. Both of these differences are due to the fact that near-infrared light is generally able to pierce through obscuration due to interstellar dust within the nebula. By clicking on the 2MASS image at the top of this page, you can start to separate the individual supergiant stars that provide the photons to illuminate the gas in the visible-light photos examined earlier.
The Spitzer infrared image is a composite of both near and mid-infrared wavelengths. Emission at 3.6 microns is depicted in blue, 4.5 microns in green, 5.8 microns in orange, and 8.0 microns in red. The mid-infrared colors (red and orange) reveal more of the dust in NGC 2070 than do shorter infrared wavelengths. The Spitzer observations penetrate the dust clouds throughout the Tarantula to reveal previously hidden sites of star formation. Within the luminescent nebula, many holes are also apparent. These voids are produced by highly energetic winds originating from the massive stars in the central star cluster. The structures at the edges of these voids are particularly interesting. Dense pillars of gas and dust, sculpted by the stellar radiation, will be the birthplace of future generations of stars. The Spitzer image provides information about the composition of the material at the edges of the voids. The surface layers closest to the massive stars are subject to the most intense stellar radiation. Here, the atoms are stripped of their electrons, and the green color of these regions is indicative of the radiation from this highly excited, or 'ionized,' material. The red filaments seen throughout the image reveal the presence of molecular material thought to be rich in hydrocarbons.
Mid-Infrared: IRAS and Far-Infrared: IRAS
In the low-resolution long-wavelength infrared images (above) taken with IRAS, red denotes the brighter regions and blue symbolizes the fainter emission features. Most of the emission at these wavelengths result from dust grains absorbing visible and UV light, being heated, and then re-radiating the energy as infrared light. This pair of images provides a clear example of how important spatial resolution can be in allowing astronomers to successfully interpret data. The image on the right was obtained at a wavelength of 100 microns and is suggestive of a single peak of far-infrared light, corresponding to the position of the central regions of the nebula. The other image (above left) was taken at a shorter wavelength of 25 microns, and has higher spatial resolution; that is, one is able to see smaller details. The shorter wavelength data reveals that there is more than one source of far-IR light. If the effective resolution could be improved beyond the 0.5 arcmin seen in this photo, you would see many more individual sources of emission buried within the central blob. The weak secondary source of far-IR light to the southwest (lower right) in both images is spatially coincident with the smaller nebulosity seen in the visible-light images examined above. For a spectacular wide-area infrared mosaic of the Large Magellanic Cloud, including the Tarantula Nebula, click here.
Ultraviolet: ASTRO-1 UIT
The ultraviolet view (above) of NGC 2070 reveals the major components of the nebula identified at other wavelengths. We see a bright saturated region in the center and many other smaller and localized sources of emission. Ultraviolet light is a good tracer of newborn stars, and this photograph shows that star formation is occurring throughout the nebula. In particular, note the density enhancement in star formation towards the southwest, which can also be seen in the infrared and visible-light pictures.
The most noticeable feature in the x-ray image (above) is the bright point
source near the southern edge of the field of view. A consultation with the
NASA/IPAC Extragalactic Database (NED) reveals the source of the
emission: NGC 2060, a
supernova remnant (SNR)
These gaseous remnants of supernova explosions are
often seen in x-ray (and radio) images, the result of emission from highly
energetic electrons and particles spewed into the interstellar medium upon the
explosive death of the progenitor star. The fainter (green) emission in the
center of the image, and to the immediate south, is the faint glow from a
population of other older and weaker SNR distributed throughout the cluster.
We learned earlier in this gallery that the Tarantula Nebula is home to many
supergiant stars. At any moment, a snapshot of any dense region of supergiant
stars will show a mixture of newborn stars and supernovae, the signature of
stars who those that have lived fast and died young.