Feb 21 2012

From The Space Library

RELEASE: 12-056 NASA'S CHANDRA FINDS FASTEST WIND FROM STELLAR-MASS BLACK HOLE

WASHINGTON -- Astronomers using NASA's Chandra X-ray Observatory have clocked the fastest wind yet discovered blowing off a disk around a stellar-mass black hole. This result has important implications for understanding how this type of black hole behaves. The record-breaking wind is moving about 20 million mph, or about 3 percent of the speed of light. This is nearly 10 times faster than had ever been seen from a stellar-mass black hole. Stellar-mass black holes are born when extremely massive stars collapse. They typically weigh between five and 10 times the mass of the sun. The stellar-mass black hole powering this super wind is known as IGR J17091-3624, or IGR J17091 for short. "This is like the cosmic equivalent of winds from a category five hurricane," said Ashley King from the University of Michigan, lead author of the study published in the Feb. 20 issue of The Astrophysical Journal Letters. "We weren't expecting to see such powerful winds from a black hole like this." The wind speed in IGR J17091 matches some of the fastest winds generated by supermassive black holes, objects millions or billions of times more massive. "It's a surprise this small black hole is able to muster the wind speeds we typically only see in the giant black holes," said co-author Jon M. Miller, also from the University of Michigan. "In other words, this black hole is performing well above its weight class." Another unanticipated finding is that the wind, which comes from a disk of gas surrounding the black hole, may be carrying away more material than the black hole is capturing. "Contrary to the popular perception of black holes pulling in all of the material that gets close, we estimate up to 95 percent of the matter in the disk around IGR J17091 is expelled by the wind," King said. Unlike winds from hurricanes on Earth, the wind from IGR J17091 is blowing in many different directions. This pattern also distinguishes it from a jet, where material flows in highly focused beams perpendicular to the disk, often at nearly the speed of light. Simultaneous observations made with the National Radio Astronomy Observatory's Expanded Very Large Array showed a radio jet from the black hole was not present when the ultra-fast wind was seen, although a radio jet is seen at other times. This agrees with observations of other stellar-mass black holes, providing further evidence the production of winds can stifle jets. The high speed for the wind was estimated from a spectrum made by Chandra in 2011. Ions emit and absorb distinct features in spectra, which allow scientists to monitor them and their behavior. A Chandra spectrum of iron ions made two months earlier showed no evidence of the high-speed wind, meaning the wind likely turns on and off over time. Astronomers believe that magnetic fields in the disks of black holes are responsible for producing both winds and jets. The geometry of the magnetic fields and rate at which material falls towards the black hole must influence whether jets or winds are produced. IGR J17091 is a binary system in which a sun-like star orbits the black hole. It is found in the bulge of the Milky Way galaxy, about 28,000 light years away from Earth. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

RELEASE: 12-059 NASA ADMINISTRATOR ANNOUNCES SENIOR LEADERSHIP CHANGES

WASHINGTON -- NASA Administrator Charles Bolden announced Tuesday changes to his senior leadership team. Associate Administrator Chris Scolese was named director of NASA's Goddard Space Flight Center in Greenbelt, Md., and Robert Lightfoot, director of the agency's Marshall Space Flight Center in Huntsville, Ala., will serve as acting associate administrator. Both will assume their new responsibilities on March 5. Scolese, who has been with NASA since 1987, succeeds Robert Strain, who announced his decision to return to private industry in January. Lightfoot joined NASA in 1989 as a test engineer and program manager at Marshall. Lightfoot's deputy, Gene Goldman, will serve as Marshall's acting center director. "Both Chris and Robert are dedicated public servants who have a passion for NASA and exploration," Bolden said. "We are fortunate to have such talented and experienced leaders who are capable of assuming these critical responsibilities during this important time." As associate administrator, Lightfoot will be the agency's highest-ranking civil servant, responsible for oversight and integration of NASA's broad efforts in human space flight, science and aeronautics. At Goddard, Scolese will lead a major U.S. laboratory for developing and operating unmanned scientific spacecraft. Goddard manages many of NASA's Earth observation, astronomy and space physics missions. It was established in 1959 as NASA's first space flight facility. "I am excited with the depth and diversity of experiences Chris and Robert will bring to their new roles," Bolden added. "I know the entire NASA family will wish them continued success as they begin these new challenges." Scolese served as the agency's acting administrator in 2009 and was previously NASA's chief engineer. As chief engineer, Scolese was responsible for ensuring that development efforts and mission operations within the agency were planned and conducted on a sound technical and management basis. He also served as deputy associate administrator in the Office of Space Science at Headquarters and previously served as deputy director of Goddard, Earth Orbiting Satellite program manager, and deputy director of flight programs and projects for Earth Science. Lightfoot began his NASA career as a test engineer and manager for the space shuttle main engine technology test bed program. He then served in leadership positions at Marshall, Stennis Space Center in Bay St. Louis, Miss., and Headquarters. In 1998, Lightfoot was named deputy division chief of Marshall's Propulsion Test Division. He joined Stennis in 1999 as chief of Propulsion Test Operations where he managed space shuttle main engine testing and multiple NASA, Department of Defense, and industry rocket engine test programs. From 2003 to 2005, he was assistant associate administrator for the Space Shuttle Program, Office of Space Flight, at Headquarters. Both men are highly honored NASA leaders, earning the Presidential Rank Award of Meritorious Executive and agency medals for outstanding leadership.

CONTRACT RELEASE: C12-004 NASA CONTRACT MODIFICATION FOR ENGINEERING AND SUPPORT SERVICES

HUNTSVILLE, Ala. -- NASA has signed its final contract option with InfoPro Corp. in Huntsville to continue engineering technicians and trades support services for the agency's Marshall Space Flight Center. The $45.7 million contract modification includes $4.1 million for mission services and a potential maximum order quantity value of $41.6 million for additional support services that are available through orders under the indefinite delivery, indefinite quantity portion of the contract. The contract covers a wide range of engineering technicians and other trade skills to perform testing, ground and space-based research, test operations, data analysis, machine and electrical shop operations, and other technical activities. The one-year contract option begins on March 1, 2012. The performance based, cost-plus-award-fee, mission services contract with an indefinite delivery, indefinite quantity portion has a potential mission services value of $56.9 million and a potential maximum order quantity value of $150.8 million, with the exercise of this final option period. The contract was originally awarded in March 2008.