Jubilant astronomers today unveiled humankind’s most spectacular views of the universe, as captured by the NASA Hubble Space Telescope’s new Advanced Camera for Surveys (ACS). They also reported that Hubble is operating superbly since the March servicing mission and are looking forward to more pictures from the newly revived NICMOS camera.
“The ACS is opening a wide new window onto the universe. These are among the best images of the distant universe humans have ever seen,” says Johns Hopkins University astronomer Holland Ford, the lead scientist in the ACS’ seven-year development. “The ACS will let us obtain the deepest image of the universe for the foreseeable future,” added astronomer Garth Illingworth, the deputy leader for the ACS.
The camera’s tenfold increase in efficiency will open up much anticipated new “discovery space” for Hubble. “ACS will allow us to push back the frontier of the early universe. We will be able to enter the ‘twilight zone’ period when galaxies were just beginning to form out of the blackness following the cooling of the universe from the big bang,” says Ford.
“The first astronomical images from the new Advanced Camera for Surveys are remarkable, breathtaking,” said Dr. David Leckrone, Hubble Space Telescope Senior Project Scientist at NASA’s Goddard Space Flight Center in Greenbelt, MD. “They’re everything we expected and more. The only problem is doing them full justice as we try to show them to the public on ‘old-fashioned’ television, or in newspapers or magazines.”
Among the suite of four “suitable-for-framing” ACS science demonstration pictures released today is a stunning view of a colliding galaxy, dubbed the “Tadpole,” located 420 million light-years away. Unlike textbook images of stately galaxies, the Tadpole, with a long tidal tail of stars, looks like a runaway pinwheel firework. It captures the essence of our dynamic, restless and violent universe.
But what came as an unexpected bonus is the enormous number of galaxies beyond the Tadpole galaxy — twice the number in the legendary Hubble Deep Field (HDF) in 1995 (as many as 6,000 galaxies). Amazingly, the ACS picture was taken in one-twelfth the time it took for the original HDF — and in blue light sees even fainter objects than the HDF. Like the HDF, the galaxies stretch back to nearly the beginning of time and contain myriad shapes that are snapshots of galaxies throughout the universe’s 13-billion-year evolution. The ACS images are so sharp astronomers can identify “the building blocks” of galaxies, colliding galaxies, an exquisite “Whitman’s Sampler” of galaxies, and extremely distant galaxies in the field. The ACS image of the Tadpole illustrates the dramatic gains over Wide Field Planetary Camera 2 that were expected from doubling the area and resolution, and five times improvement in sensitivity.
The other pictures include a stunning collision between two spiral galaxies — dubbed “The Mice” — that presage what may happen to our own Milky Way several billion years in the future when it collides with the neighboring galaxy in the constellation Andromeda. Computer simulations made by J. Barnes and J. Hibbard show that we are seeing the collision of The Mice approximately 160 million years after their closest encounter. Running the simulations forward in time shows that the two galaxies will eventually merge, forming an elliptical-like galaxy. A similar fate may await the Milky Way and the Andromeda galaxies.
Looking closer to home, ACS imaged the “Cone Nebula,” a craggy-looking mountaintop of cold gas and dust that is a cousin to Hubble’s iconic “pillars of creation” in the Eagle Nebula, photographed in 1995.
Peering into a celestial maternity ward called the M17 Swan Nebula, the ACS revealed a watercolor fantasy-world tapestry of vivid colors and glowing ridges of gas. Embedded in this crucible of star creation are embryonic planetary systems.
Mounted aboard the world’s premier optical-ultraviolet telescope, the ACS is a camera of superlatives. It is expected to go beyond the sensitvitiy of the largest ground-based telescope to eventually see the very faintest objects ever. Its camera delivers a panoramic crispness comparable to that of a wide-screen IMAX movie, a staggering 16 million picture elements (megapixels) per snapshot (typical consumer cameras are 2 to 4 megapixels).
The new high-tech mechanical “refrigerator” installed on Hubble during the recent SM3B servicing mission has successfully pumped most of the heat out of the interior of the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), achieving the target temperature for neon gas passing through the instrument of 70 degrees Kelvin (-203 degrees Centigrade or -333 degrees Fahrenheit). Since entering this new phase of self-regulated operation, the NICMOS Cooling System has successfully maintained 70K to within a few hundredths of one degree.
Engineers are now in the process of checking out the operation of the resuscitated NICMOS instrument. By early June, scientists expect to release the first astronomical images taken with the NICMOS since 1998, when it was still being cooled by a rapidly depleting block of solid nitrogen ice. “One might now say that our new mechanical cooler has taken infrared astronomy out of the ice age,” said Leckrone.
The new rigid solar arrays, working with the new Power Control Unit, are generating 27 percent more electrical power than the previous arrays. This doubles the electrical power that we are able to allocate to the scientific instruments on Hubble. The new reaction wheel is operating normally.
After a brief period of normal operation following SM3B, Hubble’s Gyro Number 3 has reverted to the same anomalous operation that it displayed prior to the mission. Engineers anticipate that its life may be shortened because of a higher than desired motor current being drawn through electrical wires (flex leads) that are known to break. Nevertheless, at this time, Gyro 3 is fully operational.
Nearly a month ago, the Space Telescope Imaging Spectrograph and the Wide Field and Planetary Camera 2 resumed science observations.
“This servicing mission has turned out to be an extraordinary success,” said Leckrone. “It was the most difficult and complicated Hubble servicing mission attempted to date and our observatory came through it with flying colors.”
Electronic image files, animation and additional information are available on the Internet at:
http://oposite.stsci.edu/pubinfo/pr/2002/11
http://oposite.stsci.edu/pubinfo/latest.html
http://oposite.stsci.edu/pubinfo/pictures.html and
http://hubblesite.org/go/news
Visitors to the STScI website called “HubbleSite” at http://hubblesite.org will be able to download high-resolution screen savers of each of the images. They will also be able to use simple Internet tools to photographically pan and zoom into the pictures to see the ACS’ exquisite detail. Dynamics of galaxy collisions are illustrated in an accompanying webpage at http://hubblesite.org/go/encounters.
