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Scientists probe black hole's inner sanctum ROCHESTER INSTITUTE OF TECHNOLOGY NEWS RELEASE Posted: January 9, 2006 How does matter spiral its way to the center of a galaxy and into the mouth of a supermassive black hole? A new study provides the best glimpse yet at the death spiral of material as it descends into the core of a galaxy hosting a large black hole. The study predicts that, barring obstructions, the galactic debris will take about 200,000 years to make a one-way trip through the inner regions of the galaxy and into oblivion. An international team of scientists led by Kambiz Fathi at Rochester Institute of Technology, together with astronomers in Brazil, Italy, and Chile, measured the internal motions of gas surrounding the nucleus of the active galaxy NGC1097. Using sophisticated spectroscopic techniques with the Gemini South Telescope in Chile, the team measured the spiral motions of gas streaming inside the nuclear ring. Using sophisticated spectroscopic techniques with the Gemini South Telescope in Chile, the team measured the motion of matter streaming from the galaxy's spiral arms to the heart of the galaxy. The observations zoomed in 10 times closer to the supermassive black hole than ever before, to see clouds of material within 10 light-years of the galactic core. Previous observations of this type of environment have detected gas clouds located between 100 and 1,000 light-years from the galaxy's nucleus. Fathi presented the team's results at the 207th meeting of the American Astronomical Society Jan. 9 in Washington, D.C. "It is the first time anyone has been able to follow gas this close to the supermassive black hole in the center of another galaxy," says Fathi, a postdoctoral scholar at RIT. "The work of our team confirms the main theories that have never been observationally confirmed at this level. We have been able to show that it is possible to measure these velocities down to these scales." Modeling the galaxy's spectra revealed the dynamic shifts in the gas and showed the spiral arms pulling gas from about a thousand light-years out from the center to the nucleus at 52 kilometers (31 miles) per second. Previous imaging by the Hubble Space Telescope and the European Southern Observatory Very Large Telescope has shown structure inside the central ring of NGC1097. The Gemini data complement this with a velocity map of the gas inside the ring. "When we extrapolate our last data points, about 30 light-years from the black hole, this is where we find that it would take about 200,000 years for the gas to travel the last leg of its one-way journey to the supermassive black hole," says Fathi. The team measured the streaming motions toward the black hole by using two-dimensional spectroscopy to capture spectral data at several thousand points surrounding the nucleus of the galaxy. "The resolution of this data is unprecedented when you look at how we were able to isolate so many different points around the nucleus of this galaxy and acquire a spectrum for each point at once," says team member Thaisa Storchi Bergmann of Instituto de Fisica in Brazil. "This paints an incredibly detailed picture of the region around the black hole and gives us a new glimpse at something we could only imagine before." The technology that allows these types of observations is called integral field spectroscopy. It takes light from many different parts of the telescope's field simultaneously and splits the light from each region into a rainbow or spectrum of light. "This allows astronomers to do in 30 minutes what would have taken four nights a decade ago," says Fathi. NGC1097 is located about 47 million light-years away in the southern constellation Fornax. This work used data from the Gemini Observatory's Multi-Object Spectrograph integral field unit and the Hubble Space Telescope's high resolution Advanced Camera for Surveys. Project collaborators include Thaisa Storchi-Bergmann, UFRGS, Brazil; David Axon and Andrew Robinson, RIT, USA; Alessandro Capetti, INAF-Turin, Italy, Alessandro Marconi, INAF-Florence, Italy; Rogemar Riffel, UFRGS, Brazil, and Claudia Winge, Gemini Observatory, Chile. |
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If at first you don't succeed, keep on trying. That is what the astronauts of space shuttle Endeavour's maiden voyage did in their difficult job of rescuing a wayward communications satellite. Spacewalkers were unable to retrieve the Intelsat 603 spacecraft, which had been stranded in a useless orbit, during multiple attempts using a special capture bar. So the crew changed course and staged the first-ever three-man spacewalk to grab the satellite by hand. The STS-49 astronauts describe the mission and narrate highlights in this post-flight presentation.
The mission for the crew of space shuttle Challenger's April 1984 flight was two-fold -- deploy the experiment-laden Long Duration Exposure Facility (LDEF) and then track down the crippled Solar Max spacecraft, capture it and perform repairs during spacewalks. Initial attempts by the astronauts to grab the craft while wearing the Manned Maneuvering Unit spacewalk backpacks failed, but the crew ultimately retrieved Solar Max and installed fresh equipment while it was anchored in the payload bay. The crew narrates this post-flight presentation of home movies and highlights from mission STS-41C.
The space shuttle program was grounded for 32 months in the painful wake of the 1986 Challenger accident. Americans finally returned to space in September 1988 when shuttle Discovery safely launched for its mission to deploy a NASA communications satellite. Enjoy this post-flight presentation narrated by the astronauts as they show movies and tell the story of the STS-26 mission.
Imagine a space shuttle mission in which the astronaut crew launched two commercial and one military communications spacecraft, then conducted a pair of incredible spacewalks to recover, fix and redeploy a satellite that malfunctioned just four months earlier. The rescue mission was a success, starting with an astronaut making a catch of the spinning satellite with just his gloved-hand. Enjoy this post-flight presentation narrated by the astronauts as they tell the story of shuttle Discovery's August 1985 mission known as STS-51I.
In our continuing look back at the classic days of the space shuttle program, today we show the STS-41D post-flight presentation by the mission's astronauts. The crew narrates this film of home movies and mission highlights from space shuttle Discovery's maiden voyage in August 1984. STS-41D deployed a remarkable three communications satellites -- a new record high -- from Discovery's payload bay, extended and tested a 100-foot solar array wing and even knocked free an icicle from the shuttle's side using the robot arm.