Giant Cannibal Galaxy's Last Meal

New images show the "last meal" of a giant cannibal galaxy as it gobbles down a smaller spiral galaxy, which has been twisted and warped from being devoured.

The giant galaxy, Centaurus A (NGC 5128) is the nearest giant, elliptical galaxy, at a distance of about 11 million light-years. The galaxy hosts a supermassive black hole that is 200 million times the mass of the sun, or 50 times the mass of the black hole at the center of the Milky Way.

At the galaxy's center is an opaque dust lane that is thought to be the remains of acosmic merger between the galaxy and a smaller spiral galaxy full of dust.

Between 200 and 700 million years ago, this galaxy is believed to have consumed a smaller spiral, gas-rich galaxy — the contents of which appear to be churning inside Centaurus A's core, likely triggering new generations of stars.

First glimpses of the "leftovers" of this meal were obtained thanks to observations with the European Space Agency's Infrared Space Observatory, which revealed a 16,500 light-year-wide structure, very similar to that of a small barred galaxy.

More recently, NASA's Spitzer Space Telescope resolved this structure into a parallelogram, which can be explained as the remnant of a gas-rich spiral galaxy falling into an elliptical galaxy and becoming twisted and warped in the process. Galaxy merging is the most common mechanism to explain the formation of such giant elliptical galaxies.

The new images, taken by the European Southern Observatory's 3.58-metre New Technology Telescope (NTT) in La Silla, Chile, allow astronomers to get an even sharper view of the structure of this galaxy, completely free of obscuring dust.

What the astronomers found in the images was surprising: "There is a clear ring of stars and clusters hidden behind the dust lanes, and our images provide an unprecedentedly detailed view toward it," said Jouni Kainulainen, lead author of the paper reporting these results. "Further analysis of this structure will provide important clues on how the merging process occurred and what has been the role of star formation during it."

The technique used to observe Centaurus A could help scientists better understand star formation in galaxies.

"These are the first steps in the development of a new technique that has the potential to trace giant clouds of gas in other galaxies at high resolution and in a cost-effective way," said co-author João Alves. "Knowing how these giant clouds form and evolve is to understand how stars form in galaxies

New Experiment to Test Super Teflon in Space

Teflon-coated frying pans may scratch easily, but a souped-up version, a nanomaterial 10,000 times more durable than the ordinary non-stick stuff, is headed for the space station to see if it could someday coat the mechanical moving parts of spacecraft.

But first it must prove it can survive ultraviolet radiation, atomic oxygen, extreme temperatures and other space hazards, after blasting offMonday aboard the space shuttle Atlantis on a course for the International Space Station (ISS).

Astronauts intend to install the material outside the space station during one of the mission's planned spacewalks.

The super Teflon could theoretically slide across a surface for more than 62,000 miles (100,000 km) before wearing away, compared to ordinary Teflon that would last just a mile or so. Researchers added fluoride-coated alumina nanoparticles that helped boost the material's strength and durability, even as it retained most of the Teflon's non-stick slipperiness.

"These are low wear, low friction materials that work well in vacuum, and we want to know if they work well in space," said Greg Sawyer, a mechanical and aerospace engineer at the University of Florida. He leads a multi-university effort backed by the U.S. Air Force that designed a whole range of nanocomposite materials for space trials aboard the space station.

Better space-age materials

Sawyer worked with his former mentors at the Rensselaer Polytechnic Institute (RPI) in New York to develop nanocomposite materials for many different space applications. Super Teflon's durability and non-stick character would make it easier for moving parts within spacecraft to move, and require less energy due to less resistance from friction.

Rensselaer researchers also built conductive nanocomposites in collaboration with the U.S. Department of Energy National Renewable Energy Laboratory. One material consists of a tough polymer filled withcarbon nanotubes, or tiny cylinders made of carbon that can conduct electricity. The second conductive material involves liquid crystalline polymers, which can resist fires and many industrial chemicals.

"Conductivity experiments look at how materials with conductivity degrade over time," Sawyer told SPACE.com. "With PTSE [Teflon] and those materials you're looking at how long they can provide adequate lubrication."

Another even more futuristic material comes in the form of so-called "chameleon" coatings developed by the Air Force Research Laboratory in Ohio. These adaptive materials can change their coating surfaces based on how much friction or strength is needed.

Space trials are a go

Researchers ensured that all the nanocomposite materials flying aboard the space shuttle Atlantis could first endure vacuum tests on Earth, as a bare minimum requirement for surviving space trials. The team had to scramble in particular to develop the conductive nanocomposites and ready it for launch in less than a week.

"It was an exciting week and we weren't sure if the composites would hold up to the rigorous testing imposed on them to determine if they could even be launched into space," said Linda Schadler, a materials engineer at RPI.

The Teflon study is part of a larger Materials International Space Station Experiment - 7 (MISSE-7) that will expose materials on an outside test bed, where the experiments face intense radiation and temperatures ranging from -40 degrees to 140 degrees F (-40 degrees to 60 degrees C). Atomic oxygen formed by ultraviolet rays splitting oxygen into single atoms also poses a unique space hazard that can erode materials.

Sawyer designed a tribometer that can monitor the friction of the materials such as the super Teflon. The material sample sits on a turntable resembling a record, and stationary pin rests on top of the spinning sample.

"The sample spins under the pin, and during that we can record the forces so we know how the material is behaving," Sawyer explained.

The experimental setup automatically sends data in real-time to the ISS lab, which then forwards the info to university labs on Earth. After all the work that went into getting their materials launched into space, researchers plan on running the space trials for as long as possible.

Ultimately, MISSE experiments - which can be folded up like a suitcase – can be collected by spacewalking astronauts to be packed up and returned to Earth for waiting scientists