Triple delight in the Milky Way
Posted: Tuesday, November 10, 2009 8:30 PM by Alan Boyle
NASA / ESA / SSC / CXC / STScI |
Click for video: Color-coded images from NASA's three Great Observatories —
the Hubble, Spitzer and Chandra space telescopes — are combined to produce this
spectacular view of the Milky Way galaxy's central region. Click on the image to
watch a video about the image from the Space Telescope Science Institute.
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NASA has blended three views of our home galaxy's turbulent core to produce a picture filled with scientifically significant snap, crackle and pop. And the deeper you go into the image, the more you learn.
The composite picture of the Milky Way's center draws upon near-infrared data from the Hubble Space Telescope (shown in yellow), infrared readings from the Spitzer Space Telescope (shown in rich red) and the X-ray vision of the Chandra X-ray Observatory (shown in shades of blue and violet)
The result is an amazingly detailed, and amazingly colorful, multiwavelength view of our galaxy's core, 26,000 light-years away in the constellation Sagittarius. Among the highlights are Sagittarius A*, the bright knot of material that surrounds the Milky Way's supermassive black hole, and the "light echo" left behind by black hole blasts that faded away long ago.
"That's one interesting thing to see - this time history of a supermassive black hole that's closer to us than any other," said Chandra press scientist Peter Edmonds. X-ray imagery from the past several years chart how the light echo has changed.
Another bright bluish spot, toward the left side of the picture, marks the location of a mysterious X-ray source known as 1E 1743.1-2843. The emissions might signal the presence of a black hole or a neutron star that is sucking in material from an unseen companion, but astronomers aren't sure.
The whole region is aglow with a blue haze that represents diffuse X-ray emissions from gas that has been heated to millions of degrees. The heat comes from violent storms of energy that are being whipped up by the central black hole as well as the birth and death of massive stars. Check out Chandra's multicolored X-ray view of the galactic center for even more detail.
The infrared view from Spitzer shows a reddish haze, marking the presence of hundreds of thousands of stars that can't be seen in visible light. Those stars warm up the surrounding clouds of gas and dust, producing an infrared glow. A closer look from Spitzer's perspective reveals long filaments of dust and "pillars of creation" where newborn stars are beginning to break out of their cocoons.
The near-infrared view from Hubble highlights arcs of warm gas that have been heated up by clusters of bright, massive stars. The structures outlined in the image provide a skeleton on which to hang all the other imagery of the galactic center.
To see how the whole picture fits together, click on the wavelength tabs on this image. And to identify the points of interest in the galactic center, check out this annotated picture.
Edmonds told me that this kind of collaboration involving multiple telescopes, and particularly NASA's three Great Observatories, is increasingly becoming the rule rather than the exception. More and more astronomers are coming to the conclusion that looking at things in one range of wavelengths may not be enough to crack the mysteries of the universe.
"The younger astronomers coming through now, they see a problem, and they attack it with every tool they've got," Edmonds said. That goes double for the next generation of scientists who may be inspired by images like the one released today.
The three-in-one view of the Milky Way's core is being sent out in printed form to more than 150 planetariums, museums, libraries, schools and science centers across the country to commemorate the 400 years since Galileo Galilei turned his telescope to the heavens in 1609. Here's a list of the places where you can see the picture displayed in all its 6-foot-by-3-foot glory.
Today's image release is just one of the activities associated with the International Year of Astronomy. There's more to come. For example, you can send a message to the planet Venus via the Japanese Akatsuki probe, due for launch next year. Next week, 35 radio telescopes around the world will conduct an unprecedented 24-hour observation of nearly 250 remote quasars.
You can get your daily fix of cosmic commentary from 365 Days of Astronomy, all the way up to the end of the year. And I'm betting that the year will end with a bang: To keep up with the latest, follow the International Year of Astronomy's Twitter updates or join the Facebook group.
Join the Cosmic Log team by signing up as my Facebook friend or following b0yle on Twitter. And pick up a copy of my new book, "The Case for Pluto." If you're partial to the planetary underdogs, you'll be pleased to know that I've just set up a Facebook fan page for "The Case for Pluto."
