A beautiful picture of the Large Magellanic Cloud

Wednesday, January 11th, 2006 at 11:21 PM by Administrator

The above image has got to be one of the most beautiful images from this meeting of the American Astronomical Society (It’s much easier to appreciate in its full resolution version available online. Over 1500 images taken at the 0.9 meter at Cerro Tololo Inter-American Observatory were stitched together to make this image as part of the Magellanic Cloud Emission Line Survey (MCELS).

An emission line is a single wavelength light given off by a specific atom. Each atom (in fact, each specific ion) gives off a unique combination of emission lines. Because of their unique nature, if you see those specific wavelengths of light being emitted by a gas, you can be sure that kind of atom. So emission line spectra are to astronomers what DNA is to crime scene investigators, something that can be pinned down to an individual (in this case, an individual type of atom).

The MCELS folks looked specifically in five wavelength bands focused on the wavelengths emitted by hydrogen, doubly-ionized oxygen, and singly-ionized sulfur, as well wide red and green continuum bands. It took over 7500 images (5 colors times 1500 positions) to assemble the image above. The images were assembled in such a way as to reveal the extremely faint gas emission from interstellar gas in these galaxies. Why do this? I’ll let the MCELS principal investigator Chris Smith explain it:

“Extinction of light from dust hides most of our own galaxy from view at optical wavelengths, and it is often difficult to determine distances accurately. For these reasons, we must look beyond the Milky Way to gain a global perspective on the interstellar medium. The Magellanic Clouds provide a unique venue for studying the interstellar medium and its components on all size scales.”

If you examine these images up close, you an see what look like little bubbles, many of which are the expanding shells of heated gas from supernovas that went off in the distant past. I’m sure these two images will be a treasure to the folks studying interstellar gases and stars, but for me, they show what beautiful things are in the heavens.

Posted in Astronomy News

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