NASA’s Chandra Finds Fastest Wind From Stellar-Mass Black Hole

Artist impression of binary system containing stellar-mass black hole IGR J17091. (NASA/CXC/M.Weiss)

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….
Read more: nasa.gov

Super Solar Storm

The biggest storm on the sun in years erupted on January 22 with a huge solar flare, an Earth-directed coronal mass ejection, or CME, and a burst of fast moving, highly energetic protons that, according to NOAA’s Space Weather Prediction Center, caused the strongest solar radiation storm since September 2005. Also, Global Temperatures remain warm, a famous Star Trek actress visits a NASA center, The Zero Robotics SPHERES Challenge 2011 Finals, a fitness program teaching kids to Train Like An Astronaut and more.


http://youtu.be/gR3A0IhsP48

Vesta Likely Cold and Dark Enough for Ice

This image obtained by the framing camera on NASA's Dawn spacecraft shows the south pole of the giant asteroid Vesta. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Though generally thought to be quite dry, roughly half of the giant asteroid Vesta is expected to be so cold and to receive so little sunlight that water ice could have survived there for billions of years, according to the first published models of Vesta’s average global temperatures and illumination by the sun.

“Near the north and south poles, the conditions appear to be favorable for water ice to exist beneath the surface,” says Timothy Stubbs of NASA’s Goddard Space Flight Center in Greenbelt, Md., and the University of Maryland, Baltimore County. Stubbs and Yongli Wang of the Goddard Planetary Heliophysics Institute at the University of Maryland published the models in the January 2012 issue of the journal Icarus. The models are based on information from telescopes including NASA’s Hubble Space Telescope.

Vesta, the second-most massive object in the asteroid belt between Mars and Jupiter, probably does not have any significant permanently shadowed craters where water ice could stay frozen on the surface all the time, not even in the roughly 300-mile-diameter (480-kilometer-diameter) crater near the south pole, the authors note. The asteroid isn’t a good candidate for permanent shadowing because it is tilted on its axis at about 27 degrees, which is even greater than Earth’s tilt of roughly 23 degrees. In contrast, the moon, which does have permanently shadowed craters, is tilted at only about 1.5 degrees. As a result of its large tilt, Vesta has seasons, and every part of the surface is expected to see the sun at some point during Vesta’s year.

The presence or absence of water ice on Vesta tells scientists something about the tiny world’s formation and evolution, its history of bombardment by comets and other objects, and its interaction with the space environment. Because similar processes are common to many other planetary bodies, including the moon, Mercury and other asteroids, learning more about these processes has fundamental implications for our understanding of the solar system as a whole. This kind of water ice is also potentially valuable as a resource for further exploration of the solar system.

Though temperatures on Vesta fluctuate during the year, the model predicts that the average annual temperature near Vesta’s north and south poles is less than roughly minus 200 degrees Fahrenheit (145 kelvins). That is the critical average temperature below which water ice is thought to be able to survive in the top 10 feet or so (few meters) of the soil, which is called regolith.

Near Vesta’s equator, however, the average yearly temperature is roughly minus 190 degrees Fahrenheit (150 kelvins), according to the new results. Based on previous modeling, that is expected to be high enough to prevent water from remaining within a few meters of the surface. This band of relatively warm temperatures extends from the equator to about 27 degrees north and south in latitude.

“On average, it’s colder at Vesta’s poles than near its equator, so in that sense, they are good places to sustain water ice,” says Stubbs. “But they also see sunlight for long periods of time during the summer seasons, which isn’t so good for sustaining ice. So if water ice exists in those regions, it may be buried beneath a relatively deep layer of dry regolith.”

The modeling also indicates that relatively small surface features, such as craters measuring around 6 miles (10 kilometers) in diameter, could significantly affect the survival of water ice. “The bottoms of some craters could be cold enough on average — about 100 kelvins — for water to be able to survive on the surface for much of the Vestan year [about 3.6 years on Earth],” Stubbs explains. “Although, at some point during the summer, enough sunlight would shine in to make the water leave the surface and either be lost or perhaps redeposit somewhere else.”

So far, Earth-based observations suggest that the surface of Vesta is quite dry. However, the Dawn spacecraft is getting a much closer view. Dawn is investigating the role of water in the evolution of planets by studying Vesta and Ceres, two bodies in the asteroid belt that are considered remnant protoplanets – baby planets whose growth was interrupted when Jupiter formed.

Dawn is looking for water using the gamma ray and neutron detector (GRaND) spectrometer, which can identify hydrogen-rich deposits that could be associated with water ice. The spacecraft recently entered a low orbit that is well suited to collecting gamma ray and neutron data.

“Our perceptions of Vesta have been transformed in a few months as the Dawn spacecraft has entered orbit and spiraled closer to its surface,” says Lucy McFadden, a planetary scientist at NASA Goddard and a Dawn mission co-investigator. “More importantly, our new views of Vesta tell us about the early processes of solar system formation. If we can detect evidence for water beneath the surface, the next question will be is it very old or very young, and that would be exciting to ponder.”

The modeling done by Stubbs and Wang, for example, relies on information about Vesta’s shape. Before Dawn, the best source of that information was a set of images taken by NASA’s Hubble Space Telescope in 1994 and 1996. But now, Dawn and its camera are getting a much closer view of Vesta.

“The Dawn mission gives researchers a rare opportunity to observe Vesta for an extended period of time, the equivalent of about one season on Vesta,” says Stubbs. “Hopefully, we’ll know in the next few months whether the GRaND spectrometer sees evidence for water ice in Vesta’s regolith. This is an important and exciting time in planetary exploration.”…
Read more: www.nasa.gov

Ebb and Flow: Montana Students Pick Winning Names for Moon Craft

GRAIL Artist's Rendition

PASADENA, Calif. — Twin NASA spacecraft that achieved orbit around the moon New Year’s Eve and New Year’s Day have new names, thanks to elementary students in Bozeman, Mont. Their winning entry, “Ebb and Flow,” was selected as part of a nationwide school contest that began in October 2011.

The names were submitted by fourth graders from the Emily Dickinson Elementary School. Nearly 900 classrooms with more than 11,000 students from 45 states, Puerto Rico and the District of Columbia participated in the contest. Previously named Gravity Recovery And Interior Laboratory, or GRAIL-A and -B, the washing machine-sized spacecraft begin science operations in March, after a launch in September 2011.

“The 28 students of Nina DiMauro’s class at the Emily Dickinson Elementary School have really hit the nail on the head,” said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology in Cambridge, Mass. “We were really impressed that the students drew their inspiration by researching GRAIL and its goal of measuring gravity. Ebb and Flow truly capture the spirit and excitement of our mission.”……
Read more: www.nasa.gov

The largest galaxy cluster in early universe

Composite image of the El Gordo galaxy cluster. (X-ray: NASA/CXC/Rutgers/J. Hughes et al; Optical: ESO/VLT & SOAR/Rutgers/F. Menanteau; IR: NASA/JPL/Rutgers/F. Menanteau )

An exceptional galaxy cluster, the largest seen in the distant universe, has been found using NASA’s Chandra X-ray Observatory and the National Science Foundation-funded Atacama Cosmology Telescope (ACT) in Chile.

Officially known as ACT-CL J0102-4915, the galaxy cluster has been nicknamed “El Gordo” (“the big one” or “the fat one” in Spanish) by the researchers who discovered it. The name, in a nod to the Chilean connection, describes just one of the remarkable qualities of the cluster, which is located more than seven billion light years from Earth. This large distance means that it is being observed at a young age.

“This cluster is the most massive, the hottest, and gives off the most X-rays of any known cluster at this distance or beyond,” said Felipe Menanteau of Rutgers University in New Brunswick, N.J., who led the study.

Galaxy clusters, the largest objects in the universe that are held together by gravity, form through the merger of smaller groups or sub-clusters of galaxies. Because the formation process depends on the amount of dark matter and dark energy in the universe, clusters can be used to study these mysterious phenomena.

Dark matter is material that can be inferred to exist through its gravitational effects, but does not emit and absorb detectable amounts of light. Dark energy is a hypothetical form of energy that permeates all space and exerts a negative pressure that causes the universe to expand at an ever-increasing rate.

“Gigantic galaxy clusters like this are just what we were aiming to find,” said team member Jack Hughes, also of Rutgers. “We want to see if we understand how these extreme objects form using the best models of cosmology that are currently available.”

Although a cluster of El Gordo’s size and distance is extremely rare, it is likely that its formation can be understood in terms of the standard Big Bang model of cosmology. In this model, the universe is composed predominantly of dark matter and dark energy, and began with a Big Bang about 13.7 billion years ago.

The team of scientists found El Gordo using ACT thanks to the Sunyaev-Zeldovich effect. In this phenomenon, photons in the cosmic microwave background interact with electrons in the hot gas that pervades these enormous galaxy clusters. The photons acquire energy from this interaction, which distorts the signal from the microwave background in the direction of the clusters. The magnitude of this distortion depends on the density and temperature of the hot electrons and the physical size of the cluster.

X-ray data from Chandra and the European Southern Observatory’s Very Large Telescope, an 8-meter optical observatory in Chile, show that El Gordo is, in fact, the site of two galaxy clusters running into one another at several million miles per hour. This and other characteristics make El Gordo akin to the well-known object called the Bullet Cluster, which is located almost 4 billion light years closer to Earth.

As with the Bullet Cluster, there is evidence that normal matter, mainly composed of hot, X-ray bright gas, has been wrenched apart from the dark matter in El Gordo. The hot gas in each cluster was slowed down by the collision, but the dark matter was not…..
Read more: nasa.gov

NORAD and Satellite Technology Help Santa Deliver

NORAD Tracks Santa. Credit: NORAD

According to the U.S. Department of Commerce Census Bureau, the world’s population is approximately 7 billion (6,979,978,073+) people. Santa Claus has had to adapt over the years to having less and less time to deliver gifts to more people. To better assure prompt deliveries and safe flights, higher technology systems are increasingly being used by the United States Northern Command at Peterson Air Force Base, Colo., to support the North American Aerospace Defense Command (NORAD).

NORAD is a joint United States and Canadian organization which provides aerospace warning and control. The United States Air Force (USAF) uses ground based radars, National Oceanic and Atmospheric Administration (NOAA) operational satellites provided by NASA Goddard Space Flight Center, as well as Santa Cams, Google maps, and jet fighter aircraft.

Global Positioning System (GPS) satellite information and carefully timed gravity assists from the sun, moon, and/or Earth are used to speed Santa’s sleigh faster and more precisely than ever before.

Multi-variable numerical modeling improvements in the solar wind, auroras, geomagnetic force fields, and space/Earth weather predictions are also being credited for important improved sleigh routing efficiencies. Rudolph (the red-nosed lead reindeer) provides a great infrared (warm) signature for the satellite instruments to focus on. The satellite data indicates where fog is and Rudolph can take over the reins from Santa as they use microwave data to know where the rain, snow, and ice are for those precise landing adjustments.

From 22,300 miles in space, NORAD will use for the first time the GOES-15 (covers the U.S. west coast and Pacific Ocean areas) significantly improved Earth location accuracy and heat detection infrared equipment from various satellites. Rudolph’s nose gives off an infrared signature similar to a small missile launch and satellites can detect Rudolph’s bright red nose very precisely.

Artist's concept of GOES-15 in orbit being used to help track Santa. Image Credit: NASA/Honeywell Tech Solutions, C. Meaney

NOAA, NASA, and the USAF have satellites expertly positioned and additional volunteers are supporting the improved Santa tracking beginning after sundown on Christmas Eve December 24. Near “real time” public updates of progress should be available from the web site http://www.noradsanta.org/ NORAD Santa and thanks to worldwide corporate and international support updates will be provided in eight languages.

NASA is in the process of checking out the new NPOESS Preparatory Project (NPP) satellite, launched in October. NPP will provide even more precise and more timely updates of weather information in the years ahead so Santa and his reindeer team can safely deliver more and more presents in all weather conditions in one night!

To track Santa using NORAD, visit: http://www.noradsanta.org
www.nasa.gov