Tag Archives: xrays

Dead Star and Distant Black Holes Dazzle in X-Rays

Two new views from NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, showcase the telescope’s talent for spying objects near and far. One image shows the energized remains of a dead star, a structure nicknamed the “Hand of God” after its resemblance to a hand. Another image shows distant black holes buried in blankets of dust.

“NuSTAR’s unique viewpoint, in seeing the highest-energy X-rays, is showing us well-studied objects and regions in a whole new light,” said Fiona Harrison, the mission’s principal investigator at the California Institute of Technology in Pasadena, Calif. (more…)

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Do Black Holes Come in Size Medium?

Black holes can be petite, with masses only about 10 times that of our sun — or monstrous, boasting the equivalent in mass up to 10 billion suns. Do black holes also come in size medium? NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, is busy scrutinizing a class of black holes that may fall into the proposed medium-sized category.

“Exactly how intermediate-sized black holes would form remains an open issue,” said Dominic Walton of the California Institute of Technology, Pasadena. “Some theories suggest they could form in rich, dense clusters of stars through repeated mergers, but there are a lot of questions left to be answered.” (more…)

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Science Benefits From Diverse Landing Area of NASA Mars Rover

PASADENA, Calif. — NASA’s Curiosity rover is revealing a great deal about Mars, from long-ago processes in its interior to the current interaction between the Martian surface and atmosphere.

Examination of loose rocks, sand and dust has provided new understanding of the local and global processes on Mars. Analysis of observations and measurements by the rover’s science instruments during the first four months after the August 2012 landing are detailed in five reports in the Sept. 27 edition of the journal Science. (more…)

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Taking a Robotic Geologist to Mars

As Mars rover Curiosity makes its final approach to the Red Planet, two UA geoscientists are getting ready to help solve some of the mysteries of its geologic past.

On Aug. 5, at about 10:30 p.m., an already busy summer will kick into overdrive for University of Arizona geosciences professor Bob Downs and one of his graduate students, Shaunna Morrison. At that time – provided everything goes as planned – Curiosity, the most sophisticated exploration vehicle ever sent to another planet, will parachute toward the Martian surface faster than the speed of sound after a nine-month journey through space. And as soon as it sinks its six wheels into the red dust, the two scientists specializing in mineralogy will have not one, but two planets to deal with.

As “primary data downlink leaders” designated by NASA, Downs and Morrison are part of a team of scientists tasked with the identification of rocks that Curiosity will encounter during its two-year expedition across the floor of Gale Crater near the Martian equator. (more…)

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Detecting Cancer with Lasers Has Limited Use, Say Mu Researchers

COLUMBIA, Mo. — One person dies every hour from melanoma skin cancer in the United States, according to the American Cancer Society. A technique known as photoacoustics can find some forms of melanoma even if only a few cancerous cells exist, but a recent study by University of Missouri researchers found that the technique was limited in its ability to identify other types of cancer. Attaching markers, called enhancers, to cancer cells could improve the ability of photoacoustics to find other types of cancer and could save lives thanks to faster diagnoses, but the technique is in its early stages.

“Eventually, a photoacoustic scan could become a routine part of a medical exam,” said Luis Polo-Parada, assistant professor of pharmacology and physiology and resident investigator at the MU Dalton Cardiovascular Research Center. “The technique doesn’t use X-rays like current methods of looking for cancer. It could also allow for much earlier detection of cancer. Now, a cancerous growth is undetectable until it reaches approximately one cubic centimeter in size. Photoacoustics could potentially find cancerous growths of only a few cells. Unfortunately, our research shows that, besides some cases of melanoma, the diagnostic use of photoacoustics still has major limitations. To overcome this problem, the use of photoacoustic enhancers like gold, carbon nanotubes or dyed nanoparticles is needed.” (more…)

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Researchers Develop New Amp to Study the Universe

Researchers at NASA’s Jet Propulsion Laboratory and the California Institute of Technology, both in Pasadena, have developed a new type of amplifier for boosting electrical signals. The device can be used for everything from studying stars, galaxies and black holes to exploring the quantum world and developing quantum computers.

“This amplifier will redefine what it is possible to measure,” said Jonas Zmuidzinas, chief technologist at JPL, who is Caltech’s Merle Kingsley Professor of Physics and a member of the research team. (more…)

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A New Way of Looking at Photosystem II

Berkeley Lab and SLAC Researchers Study Key Protein Complex Crucial to Photosynthesis

Future prospects for clean, green, renewable energy may hinge upon our ability to mimic and improve upon photosynthesis – the process by which green plants, algae and some bacteria convert solar energy into electrochemical energy. An artificial version of photosynthesis, for example, could use sunlight to produce liquid fuels from nothing more than carbon dioxide and water. First, however, scientists need a better understanding of how a large complex of proteins, called photosystem II, is able to split water molecules into oxygen, electrons and hydrogen ions (protons). A new road to reaching this understanding has now been opened by an international team of researchers, led by scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and SLAC National Accelerator Laboratory.

Using ultrafast, intensely bright pulses of X-rays from SLAC’s Linac Coherent Light Source (LCLS), the research team produced the first ever images at room temperature of microcrystals of the photosystem II complex. Previous imaging studies, using X-rays generated via synchrotron radiation sources, required cryogenic freezing, which alters the samples. Also, to catalyze its reactions, photosystem II relies upon an enzyme that contains a manganese-calcium cluster that is highly sensitive to radiation. With the high-intensity femtosecond X-ray pulses of the LCLS, the research team was able to record intact images of these clusters before the radiation destroyed them. (more…)

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Fastest Wind From Stellar Mass Black Hole Discovered

ANN ARBOR, Mich.— The fastest wind ever discovered blowing off a disk around a stellar-mass black hole has been observed by a team of astronomers that includes a University of Michigan doctoral student.

Using NASA’s Chandra X-ray Observatory, an orbiting telescope, they clocked the record-breaking super wind at about 20 million mph, or about 3 percent of the speed of light. This is nearly 10 times faster than astronomers had previously observed from a stellar-mass black hole. (more…)

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