Stellar Debris in the Large Magellanic Cloud
The “lifestyles” of 75 neighboring galaxies are illuminated in this poster from NASA’s Spitzer Space Telescope.
In this composite, blue colors reveal light from an older population of stars. Tints of green represent organic molecules called polycyclic aromatic hydrocarbons, while red lumps show clouds of warm dust and gas heated by radiation from newborn stars.
The galaxies are organized by shape, according to the Hubble-Tuning Fork.
In this structure, elliptical galaxies sit on the left side of the poster, creating the tuning fork’s handle. They are designated by the letter “E”, and given a number from zero to seven. An “E0” galaxy looks round, while an E7 galaxy is very long and thin.
Spiral galaxies are located to the right side of the poster creating the fork’s two prongs. The top prong is made up of regular spiral galaxies, and identified by the letter “S.” Barred spiral galaxies make up the bottom prong, and are branded “SB.” Meanwhile, letters – “a”, “b”, and “c” – indicate how tightly the spiral arms are wound. An “Sa” galaxy’s arms are wound very tightly, while an “Sc” galaxy’s spiral arms are very loosely wound.
Irregular galaxies are organized on bottom-left side of the poster because they were not represented in Hubble’s original Tuning Fork.
Great Observatories Explore Galactic Center
Where can a telescope take you? Four hundred years ago, a telescope took Galileo to the Moon to discover craters, to Saturn to discover rings, to Jupiter to discover moons, to Venus to discover phases, and to the Sun to discover spots. Today, in celebration of Galileo’s telescopic achievements and as part of the International Year of Astronomy, NASA has used its entire fleet of Great Observatories, and the Internet, to bring the center of our Galaxy to you. Pictured above, in greater detail and in more colors than ever seen before, are the combined images of the Hubble Space Telescope in near-infrard light, the Spitzer Space Telescope in infrared light, and the Chandra X-ray Observatory in X-ray light. A menagerie of vast star fields is visible, along with dense star clusters, long filaments of gas and dust, expanding supernova remnants, and the energetic surroundings of what likely is our Galaxy’s central black hole. Many of these features are labeled on a complementary annotated image. Of course, atelescope’s magnification and light-gathering ability create only an image of what a human could see if visiting these places. To actually go requires rockets.
Two spectacular tails of X-ray emission have been seen trailing behind a galaxy using the Chandra X-ray Observatory.
At the front of the tail is the galaxy ESO 137-001. The brighter of the two tails has been seen before and extends for about 260,000 light years. The detection of the second, fainter tail, however, was a surprise to the scientists.
The X-ray tails were created when cool gas from ESO 137-001 (with a temperature of about ten degrees above absolute zero) was stripped by hot gas (about 100 million degrees) as it travels towards the center of the galaxy cluster Abell 3627. What astronomers observe with Chandra is essentially the evaporation of the cold gas, which glows at a temperature of about 10 million degrees. Evidence of gas with temperatures between 100 and 1,000 degrees Kelvin in the tail was also found with the Spitzer Space Telescope.