Swift Survey Finds 'Smoking Gun' Of Black Hole Activation

The optical counterparts of many active galactic nuclei (circled) detected by the Swift BAT Hard X-ray Survey clearly show galaxies in the process of merging. These images, taken with the 2.1-meter telescope at Kitt Peak National Observatory in Arizona, show galaxy shapes that are either physically intertwined or distorted by the gravity of nearby neighbors. These AGN were known prior to the Swift survey, but Swift has found dozens of new ones in more distant galaxies.

Data from an ongoing survey by NASA's Swift satellite have helped astronomers solve a decades-long mystery about why a small percentage of black holes emit vast amounts of energy.

Only about one percent of supermassive black holes exhibit this behavior. The new findings confirm that black holes "light up" when galaxies collide, and the data may offer insight into the future behavior of the black hole in our own Milky Way galaxy. The study will appear in the June 20 issue of The Astrophysical Journal Letters.

The intense emission from galaxy centers, or nuclei, arises near a supermassive black hole containing between a million and a billion times the sun's mass. Giving off as much as 10 billion times the sun's energy, some of these active galactic nuclei (AGN) are the most luminous objects in the universe. They include quasars and blazars.

"Theorists have shown that the violence in galaxy mergers can feed a galaxy's central black hole," said Michael Koss, the study's lead author and a graduate student at the University of Maryland in College Park. "The study elegantly explains how the black holes switched on."

NASA finds water on the moon

WASHINGTON (AFP) – A "significant amount" of frozen water has been found on the moon, the US space agency said Friday heralding a giant leap forward in space exploration and boosting hopes of a permanent lunar base.

Preliminary data from a dramatic experiment on the moon "indicates the mission successfully uncovered water in a permanently shadowed lunar crater," NASA said in a statement.

"The discovery opens a new chapter in our understanding of the moon," it added, as ecstatic scientists celebrated the landmark discovery.

"Yes indeed we found water and we did not find only a little bit but a significant amount," said Anthony Colaprete, project scientist and principal investigator for the 79-million-dollar LCROSS mission.

The data was found after NASA sent two spacecraft crashing into the lunar surface last month in a dramatic experiment to probe Earth's nearest neighbor for water.

One rocket slammed into the Cabeus crater, near the lunar southern pole, at around 5,600 miles (9,000 kilometers) per hour.

Moon holds key to solar system's secrets

The rocket was followed four minutes later by a spacecraft equipped with cameras to record the impact which sent a huge plume of material billowing up from the bottom of the crater, untouched by sunlight for billions of years.

"In the 20 to 30 meter crater we found maybe about a dozen, at least, two-gallon buckets of water. This is an initial result," Colaprete told reporters.

"We are ecstatic," he added in a statement.

"Multiple lines of evidence show water was present in both the high angle vapor plume and the ejecta curtain created by the LCROSS Centaur impact.

"The concentration and distribution of water and other substances requires further analysis, but it is safe to say Cabeus holds water," Colaprete said.

Scientists had previously theorized that, except for the possibility of ice at the bottom of craters, the moon was totally dry.

Finding water on Earth's natural satellite is a major breakthrough in space exploration.

"It's very exciting, it is painting a new image of the moon," said Gregory Deloy, from the University of California hailing it as "an extraordinary discovery."

He theorized that "one of the possible source of water is a comet."

"We're unlocking the mysteries of our nearest neighbor and, by extension, the solar system," said Michael Wargo, chief lunar scientist at NASA headquarters in Washington.

"The full understanding of the LCROSS data may take some time. The data is that rich," Colaprete cautioned.

"Along with the water in Cabeus, there are hints of other intriguing substances. The permanently shadowed regions of the moon are truly cold traps, collecting and preserving material over billions of years."

Only 12 men, all Americans, have ever walked on the moon, and the last to set foot there were in 1972, at the end of the Apollo missions.

But NASA's ambitious plans to put US astronauts back on the moon by 2020 to establish manned lunar bases for further exploration to Mars under the Constellation project are increasingly in doubt.

NASA's budget is currently too small to pay for Constellation's Orion capsule, a more advanced and spacious version of the Apollo lunar module, as well as the Ares I and Ares V launchers needed to put the craft in orbit.

A key review panel appointed by President Barack Obama said existing budgets are not large enough to fund a return mission before 2020.

soucre : news.yahoo.com