NSF VIDEO: Black holes and coffee - Scientists & Engineers on Sofas (and other furn...

COMPARE AND CONTRAST AURORA SIGHTINGS

FROM:  NATIONAL SCIENCE FOUNDATION
Springtime night lights: Finding the aurora
Aurorasaurus project allows aurora-viewers around the world to compare sightings

Dance of the spirits, it's known by the Cree, one of North America's largest groups of Native Americans.

The phenomenon, called the aurora borealis in the Northern Hemisphere and aurora australis in the Southern Hemisphere, is indeed a dance of particles and magnetism between the sun and the Earth.

The sun continuously produces a solar wind of charged particles, or plasma. As that "breath" reaches Earth, it causes our planet's magnetic field to shapeshift from round to teardrop--with a long tail on the side farthest from the sun.

The teardrop-stretched field ultimately reconfigures into two parts, one controlled by Earth's magnetic field, the other by the solar wind.

The instability excites the solar-charged particles. They follow spiral paths along lines connecting Earth's north and south magnetic poles to its atmosphere.

"What happens next," says scientist Elizabeth MacDonald of the New Mexico Consortium in Los Alamos, "is one of nature's most spectacular sights: the aurora."

The light of the aurora is emitted when the charged particles collide with gases in Earth's upper atmosphere.

Glimpsing an aurora

How often the aurora is visible in an area, MacDonald says, depends upon a host of factors, including the intensity of the solar wind; the season--the aurora may be strongest around the spring and fall equinoxes; whether the sun is near the peak of its 11-year cycle; and how far someone is from what scientists call the auroral oval, the lights' ring-shaped display.

Knowing where and when an aurora is happening has been difficult to find out--until now. A new project called Aurorasaurus allows citizens around the world to track auroras and report on their progress.

Visitors to the Aurorasaurus website can see where an aurora is happening in real-time, let other Aurorasaurus visitors know of an aurora's existence, and receive "early warnings" when an aurora is likely to happen in their Earth-neighborhood.

Aurora-power

"Auroras are beautiful displays that have fascinated humans through the ages," says Therese Moretto Jorgensen, program director in the National Science Foundation's (NSF) Directorate for Geosciences, which, along with NSF's Directorate for Education and Human Resources and Directorate for Computer & Information Science & Engineering, funds Aurorasaurus through NSF's INSPIRE program.

INSPIRE supports projects whose scientific advances lie outside the scope of a single program or discipline, lines of research that promise transformational advances, and prospective discoveries at the interfaces of scientific boundaries.

"Auroras are of major interest," says Moretto Jorgensen, "because of their effects on Earth. There's a close relationship between auroras and the magnetic variations that pose a threat to the power grid.

"A better understanding of when and where auroras happen will help us develop models that can forecast these potentially hazardous events."

Amassing new data

Scientists hope that by amassing data from thousands of aurora-viewers, they'll learn more about the solar storms that can disrupt or destroy Earth's communications networks and affect the planet's navigation, pipeline, electrical and transportation systems.

During one solar storm in 1989, transformers in New Jersey melted and wiped out power all the way to Quebec, leaving millions of people in the dark.

The largest such solar storm in history, the Carrington Event, zapped Earth in 1859. It was so large it lit up the skies with auroras from the poles to the tropics. Electrical currents from the storm caused fires in telegraph systems and knocked out communications.

St. Patrick's Day magic in the skies

Could it happen again? Yes, if St. Patrick's Day this year is any guide.

On March 17, 2015, researchers and the public were treated to once-a-decade views. As people waited for glimpses of leprechauns, they saw something even more magical, viewers say.

Earth experienced the biggest solar storm to date of this 11-year sun cycle, sparking auroras around the world.

The St. Patrick's Day auroras, many of which were indeed green, were a fortuitous combination of events. Two days earlier, there was an explosion on the sun. The explosion, called a coronal mass ejection (CME), unleashed a blast of gas bubbles that created a strong disturbance as it collided with Earth's magnetic field.

The CME's magnetic field was directed southward, opposite to the Earth's magnetic field, and the solar wind whipped by very fast, says MacDonald.

"The storm's conditions led to a perfect environment for aurora-hunting," she says. On a scale of G1 (minor) to G5 (extreme), the storm reached a G4, or "severe" level.

The storm's Kp index, a global solar storm index, registered in the 6-8 range (9 is the highest).

Rare aurora-viewing--all the way to the southern U.S.

The strong solar wind blew for more than 24 hours, creating auroras visible as far south as the central and southern United States--a very rare occurrence.

The solar storm's peak hit during the daytime over most of the United States and Europe, but the storm persisted into the night and offered Americans and Europeans a brilliant nighttime light show.

Aurorasaurus reports came in from unusual regions: the south of England, Germany and Poland. In the United States, people spotted auroras in states such as Pennsylvania, Virginia and Colorado.

Data peak from Aurorasaurus users

Aurorasaurus participants logged more than 160 sightings during the St. Patrick's Day solar storm.

From midnight on March 17th through mid-day on March 18th, the number of registered users increased by 50 percent. Registering allows Aurorasaurus to communicate information in return, sending location-based sighting alerts.

"We combine reports to provide real-time alerts when auroras might be visible nearby," says MacDonald. "During this storm alone, we issued 361 such notifications.

"We're using Aurorasaurus data to improve auroral oval models, and to develop a better notification system using both satellite-based data and citizen science data."

Adds Moretto Jorgensen, "Auroras on a global scale are very difficult to capture using traditional scientific methods. Human observers linked through Aurorasaurus are a unique network for documenting them."

Whether on St. Patrick's Day or any other Earth-day, the aurora carries a message: take time to look up at one of the planet's most breathtaking sights.

Then look down, to be sure you can send photos of the event from your cell phone. Spirits dancing across the skies may have played havoc with its transmissions.

-- Cheryl Dybas, NSF
Investigators
Andrea Tapia
Michelle Hall
Elizabeth MacDonald

ICE MOON HANGS ON

FROM:  NASA 

Right:  Stuck on the Rings
Like a drop of dew hanging on a leaf, Tethys appears to be stuck to the A and F rings from this perspective.

Tethys (660 miles, or 1,062 kilometers across), like the ring particles, is composed primarily of ice. The gap in the A ring through which Tethys is visible is the Keeler gap, which is kept clear by the small moon Daphnis (not visible here).
This view looks toward the Saturn-facing hemisphere of Tethys. North on Tethys is up and rotated 43 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2014.

The view was acquired at a distance of approximately 1.1 million miles (1.8 million kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 22 degrees. Image scale is 7 miles (11 kilometers) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
Credit: NASA/JPL-Caltech/Space Science Institute

NASA VIDEO: TOUR OF M82 SN20114J

NASA VIDEO: TOUR OF RX J1131-1231

NSF SUPPORTS DIVERSITY WITH ASTRONOMY PROGRAM

FROM:  NATIONAL SCIENCE FOUNDATION 

Making stars

Astronomy program provides tools, support to enhance diversity

October 7, 2014

Like so many other children, Fabienne Bastien did not like to go to sleep at bedtime.

She recalls her mother lying alongside her, telling her to look out her window into the night sky because her guardian angel was there. And as she searched for this elusive guardian angel, what she found instead was the moon and stars, among other astronomical delights.

Despite Washington, D.C., metro-area light pollution that can restrict one's view of the cosmos, Bastien pinpoints that moment as the one when she got hooked on astronomy, knowing it held her future, if not an actual guardian angel.

Many astronomers and astrophysicists speak of that same source of inspiration. But, while our solar system's immensity and beauty have an almost universal appeal, the astronomy and astrophysics career field has had very little representation from minority populations.

In a study done by the American Astronomical Society, which includes most professionals and many students in these fields, only 21 percent of its members is female, which is light-years ahead of the representation of African Americans and Hispanics/Latinos--1 percent and 3 percent, respectively.

Not surprisingly, those numbers have prompted a call for diversity within the astro community.

In 2008, the National Science Foundation (NSF) started a program called Partnerships in Astronomy and Astrophysics Research and Education (PAARE, pronounced "pair"). Its goal was to identify and explore ways to repair "leaks" in the astronomy/astrophysics career pipeline for minority students. In many cases, minority students would start out studying astronomy, but they weren't making it all the way through the pipeline to pursue science careers.

When Bastien finished her undergraduate degree at the University of Maryland, she too wasn't sure whether she was appropriately prepared for the rigors of a grad school education in astronomy.

"I was petrified of grad school," she said. "I hadn't taken advantage of research opportunities as an undergrad largely due to personal challenges. But also because our department was so big, I fell between the cracks there."

PAARE aimed to make the face of astronomy more inclusive by seeing that minority students like Bastien got the right mix of resources, mentoring and encouragement. The partnership found that this required a multi-faceted approach that could target those pipeline points where "leaks" were most likely and "pair" some strong astronomy programs with schools that have more diverse populations, providing mentoring and support.

In Bastien's case, the PAARE Fisk-Vanderbilt Masters-to-Ph.D. Bridge Program proved to be one where she not only got her Ph.D., but had the opportunity to analyze stellar variability data, which led to a paper in Nature, being named a Hubble fellow and to her current postdoctoral work at Penn State.

The leaky pipeline

"We currently fund several highly complementary PAARE partnerships, which attack the leaky pipeline at different stages," said Dan Evans, the NSF program director who manages PAARE funding for the Division of Astronomical Sciences. "We're deeply concerned about the underrepresentation of minority students in astronomy and are massively proud of the successes of the students and staff who have participated in PAARE. We are exposing students to cutting-edge research. We are providing important new opportunities. And mentoring is utterly critical."

Though the partnerships target different points in the pipeline, they all emphasize mentoring, access to research opportunities and resources early on. They also emphasize an infrastructure that can address both academic and personal issues that might hinder progress.

"Queens is the most diverse county in the country," said Tim Paglione, director of AstroCom NYC, a partnership between astronomers at the City Universities of New York (CUNY), the American Museum of Natural History and Columbia University. Of the current PAARE partnerships, this is the only one that focuses exclusively on undergraduate students, targeting freshmen and sophomores. It also has the added challenge of CUNY being located throughout New York City, creating unique transportation issues that can deter students who feel inadequately prepared or supported.

That's why this program only accepts four new students each year. It supports students with summer fellowships, school scholarships, transportation stipends and program-provided laptops. It also provides long-term career mentors, research mentors, travel to observatories and professional meetings and membership in the American Astronomical Society.

"The problem is gigantic, but our astronomy field is also small," Paglione said. "That means even with our little program, we can have an impact. If we graduated two students each year from underrepresented groups who then went onto graduate school, we would be one of the leading programs in the country."

Keivan Stassun started a PAARE-like partnership even before PAARE existed, using funding from his NSF CAREER award in 2003 to develop the Fisk-Vanderbilt program, which focused on the potential pipeline leak at this juncture.

"That CAREER award gave me seed funding to do things like develop a website and recruit a couple of students as research assistants," Stassun said. "The CAREER grant got the whole thing going, both in terms of cash and caché as I got buy-in from both universities."

Broader than just astronomy, Stassun' s program has admitted 78 students in physics, biology, chemistry, materials science and astronomy, with the belief that they can impact these STEM disciplines as well. "This felt like the perfect program for me," Bastien recalled. "The extra encouragement helped. I was immediately working on real science--on rare eruptive young stars--because they serendipitously had these data they needed analyzed."

Another potential leak in this pipeline comes right after college, and South Carolina State University (SCSU) partnered with the NSF-funded National Optical Astronomy Observatory and Clemson University to address the loss of minority astronomy students at this stage of their education.

"We hoped to mirror Keivan's success at Vanderbilt," said Don Walter, who started the Partnership in Observational and Computational Astronomy, based on an undergraduate physics curriculum at SCSU. "We overestimated the number of students we'd get involved, so we haven't yet seen the numbers at the grad program that we hoped for, but the momentum is there, and we believe we have the right supports in place."

The SCSU partnership admittedly has had different obstacles and issues. It doesn't have full-time researchers because SCSU is a predominantly undergraduate school. The astrophysics portion of the curriculum is a concentration, not a degree. And the STEM graduate programs are a few hours away at Clemson, not nearby.

Mentoring makes the difference

"We try to spend a lot of time with our students as soon as possible. Because they don't take their first physics courses until their second year, it would be easy for them to get lost," Walter said. "I'll ask them to come by to make sure we connect early on--even waiting outside their classrooms if my emails don't bring them in. Students need early interaction."

This is a common theme throughout PAARE partnerships. Interaction with other students at the same and more advanced levels, as well as faculty, seems critical to success.

"We've added a number of mentoring layers," Stassun said about the Fisk-Vanderbilt program. "We assign to all incoming students a pair of peer mentors known as 'bridge buddies' who are students just one year ahead, and another mentor who is a few years further ahead. That way, they can see their future in front of them. We now also have a postdocs association, where the postdocs spend three-quarters of their time on their own research, but also a quarter of their time mentoring. They hold office hours, so students can talk to them, which offers a different perspective from faculty advisers."

At SCSU, one of the biggest challenges actually has been personal and financial problems that interfere with students staying in school.

"Some good students have had major personal or family issues," he said. "Money is tight, and many students find it too difficult to balance school life with demands in their personal lives. One female student in our physics program was an A-B student, but in the middle of the semester, her parents asked her to return home to care for a sick brother. She would have been a good undergraduate student and good graduate student."

Success determined by grit?

Interestingly enough, the admissions process for these PAARE partnerships has gone beyond evaluating just grades and test scores.

Stassun referred to a Nature article that he published this year with colleague Casey Miller about the Graduate Record Examination, or GRE, gender and ethnic bias that was discovered using published data from the Educational Testing Service that makes those tests. Their study found that women score approximately 80 points lower than men on the test's math section; and African Americans, approximately 200 points lower than Whites and Asians, on average.

For that reason, Stassun and his team put together a different set of metrics to measure something he refers to as "grit" or performance character.

"We found that the most successful students weren't necessarily the ones with the highest test scores," he said. "Graduate school is about persistence, so it makes sense to try and determine a candidate's capacity for being persistent. Consequently, we have achieved a very large, diverse program with a 90-percent Ph.D. persistence rate versus the national rate which is barely better than 50 percent." In other words, 90 percent of the students at Fisk-Vanderbilt are getting their doctoral degrees. He credits that success to careful, yet diverse selection and smart mentoring.

"PAARE funding makes a difference," Walter said. "In the August American Institute of Physics newsletter, SCSU was tied for eighth position nationally in terms of African American physics bachelors of science degree graduates during the five-year period, 2008-2012. We'd only graduated 12, but because the pool is so small, we're one of the top schools. PAARE helped us provide our students with meaningful internships at places like the National Optical Astronomy Observatory, which keeps their interest alive while giving them important experience."

Ariel Diaz, who attends the CUNY program, is a PAARE student who has benefitted from those experiences and demonstrated his "grit." A former Marine, he lives in New York City with his ailing father, whom he cares for. His astronomy interest was piqued in an introductory class that was far from the "easy A" he thought it would be. However, he found he really enjoyed the class, and Paglione's team recognized a student who had the wherewithal to succeed. Today, Diaz sifts through X-ray data from Chandra Observatory, looking for signals that could indicate black holes or other astronomical events.

"He's grown as a student. He's building a vision of himself in this career," Paglione said. "And honestly, that's what we want to do here. We want our students to see that future in themselves."

-- Ivy F. Kupec
Investigators
Donald Walter
Keivan Stassun
Timothy Paglione
Related Institutions/Organizations
Fisk University
CUNY York College
University of Texas at El Paso
South Carolina State University

THE BIG, BAD & BEAUTIFUL UNIVERSE WITH CHANDRA

STELLAR SCENE FROM THE INTERNATIONAL SPACE STATION

FROM:  NASA 

On June 23, 2014, Expedition 40 Flight Engineer Reid Wiseman captured this image which connects Earth to the International Space Station and to the stars. Among the "stellar" scene is part of the constellation Orion, near the center of the frame. The U.S. laboratory or Destiny is seen in the upper right.  Image Credit: NASA

NASA STUDIES THE BIRTH OF STAR CLUSTERS

FROM:  NASA 

Stars are often born in clusters, in giant clouds of gas and dust. Astronomers have studied two star clusters using NASA's Chandra X-ray Observatory and infrared telescopes and the results show that the simplest ideas for the birth of these clusters cannot work, as described in our latest press release.

This composite image shows one of the clusters, NGC 2024, which is found in the center of the so-called Flame Nebula about 1,400 light years from Earth. In this image, X-rays from Chandra are seen as purple, while infrared data from NASA's Spitzer Space Telescope are colored red, green, and blue. A study of NGC 2024 and the Orion Nebula Cluster, another region where many stars are forming, suggest that the stars on the outskirts of these clusters are older than those in the central regions. This is different from what the simplest idea of star formation predicts, where stars are born first in the center of a collapsing cloud of gas and dust when the density is large enough. The research team developed a two-step process to make this discovery. First, they used Chandra data on the brightness of the stars in X-rays to determine their masses. Next, they found out how bright these stars were in infrared light using data from Spitzer, the 2MASS telescope, and the United Kingdom Infrared Telescope. By combining this information with theoretical models, the ages of the stars throughout the two clusters could be estimated. According to the new results, the stars at the center of NGC 2024 were about 200,000 years old while those on the outskirts were about 1.5 million years in age. In Orion, the age spread went from 1.2 million years in the middle of the cluster to nearly 2 million years for the stars toward the edges. Explanations for the new findings can be grouped into three broad categories. The first is that star formation is continuing to occur in the inner regions. This could have happened because the gas in the outer regions of a star-forming cloud is thinner and more diffuse than in the inner regions. Over time, if the density falls below a threshold value where it can no longer collapse to form stars, star formation will cease in the outer regions, whereas stars will continue to form in the inner regions, leading to a concentration of younger stars there. Another suggestion is that old stars have had more time to drift away from the center of the cluster, or be kicked outward by interactions with other stars. Finally, the observations could be explained if young stars are formed in massive filaments of gas that fall toward the center of the cluster.

The combination of X-rays from Chandra and infrared data is very powerful for studying populations of young stars in this way. With telescopes that detect visible light, many stars are obscured by dust and gas in these star-forming regions, as shown in this optical image of the region. 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 in Cambridge, Mass., controls Chandra's science and flight operations. Image credit: X-ray: NASA/CXC/PSU/K.Getman, E.Feigelson, M.Kuhn & the MYStIX team; Infrared:NASA/JPL-Caltech.

SUPERCOMPUTERS PREDICT SIGNS OF BLACK HOLES CONSUMING STARS

Right:  Black Hole Caught in a Stellar Homicide.  This computer-simulated image shows gas from a star that is ripped apart by tidal forces as it falls into a black hole. Some of the gas also is being ejected at high speeds into space.  Image Credit: NASA, S. Gezari (The Johns Hopkins University), and J. Guillochon (University of California, Santa Cruz).

FROM:  NATIONAL SCIENCE FOUNDATION 

Cosmic slurp

Georgia Tech researchers use supercomputers to understand and predict signs of black holes swallowing stars

April 14, 2014

Somewhere out in the cosmos an ordinary galaxy spins, seemingly at slumber. Then all of a sudden, WHAM! A flash of light explodes from the galaxy's center. A star orbiting too close to the event horizon of the galaxy's central supermassive black hole has been torn apart by the force of gravity, heating up its gas and sending out a beacon to the far reaches of the universe.

In a universe with tens of billions of galaxies, how would we see it? What would such a beacon look like? And how would we distinguish it from other bright, monumental intergalactic events, such as supernovas?

"Black holes by themselves do not emit light," said Tamara Bogdanovic, an assistant professor of physics at the Georgia Institute of Technology. "Our best chance to discover them in distant galaxies is if they interact with the stars and gas that are around them."

In recent decades, with improved telescopes and observational techniques designed to repeatedly survey the vast numbers of galaxies in the sky, scientists noticed that some galaxies that previously looked inactive would suddenly light up at their very center.

"This flare of light was found to have a characteristic behavior as a function of time. It starts very bright and its luminosity then decreases in time in a particular way," she explained. "Astronomers have identified those as galaxies where a central black hole just disrupted and 'ate' a star. It's like a black hole putting up a sign that says 'Here I am.'"

Using a mix of theoretical and computer-based approaches, Bogdanovic tries to predict the dynamics of events such as the black-hole-devouring-star scenario described above, also known as a "tidal disruption." Such events would have a distinct signature to someone analyzing data from a ground-based or space-based observatory.

Using National Science Foundation-funded supercomputers at the Texas Advanced Computing Center (Stampede) and the National Institute for Computational Sciences (Kraken), Bogdanovic and her collaborators recently simulated the dynamics of these super powerful forces and charted their behavior using numerical models.

Tidal disruptions are relatively rare cosmic occurrences. Astrophysicists have calculated that a Milky Way-like galaxy stages the disruption of a star only once in about 10,000 years. The luminous flare of light, on the other hand, can fade away in only a few years. Because it is such a challenge to pinpoint tidal disruptions in the sky, astronomical surveys that monitor vast numbers of galaxies simultaneously are crucial.

Huge difference

So far, only a few dozen of these characteristic flare signatures have been observed and deemed "candidates" for tidal disruptions. But with data from PanSTARRS, Galex, the Palomar Transient Factory and other upcoming astronomical surveys becoming available to scientists, Bogdanovic believes this situation will change dramatically.

"As opposed to a few dozen that have been found over the past 10 years, now imagine hundreds per year--that's a huge difference!" she said. "It means that we will be able to build a varied sample of stars of different types being disrupted by supermassive black holes."

With hundreds of such events to explore, astrophysicists' understanding of black holes and the stars around them would advance by leaps and bounds, helping determine some key aspects of galactic physics.

"A diversity in the type of disrupted stars tells us something about the makeup of the star clusters in the centers of galaxies," Bodganovic said. "It may give us an idea about how many main sequence stars, how many red giants, or white dwarf stars are there on average."

Tidal disruptions also tell us something about the population and properties of supermassive black holes that are doing the disrupting.

"We use these observations as a window of opportunity to learn important things about the black holes and their host galaxies," she continued. "Once the tidal disruption flare dims below some threshold luminosity that can be seen in observations, the window closes for that particular galaxy."

Role of supercomputer

In a recent paper submitted to the Astrophysical Journal, Bogdanovic, working with Roseanne Cheng (Center for Relativistic Astrophysics at Georgia Tech) and Pau Amaro-Seoane (Albert Einstein Institute in Potsdam, Germany), considered the tidal disruption of a red giant star by a supermassive black hole using computer modeling.

The paper comes on the heels of the discovery of a tidal disruption event in which a black hole disrupted a helium-rich stellar core, thought to be a remnant of a red giant star, named PS1-10jh, 2.7 billion light years from Earth.

The sequence of events they described aims to explain some unusual aspects of the observational signatures associated with this event, such as the absence of the hydrogen emission lines from the spectrum of PS1-10jh.

As a follow-up to this theoretical study, the team has been running simulations on Kraken and Stampede, as well as Georgia Tech's Keeneland supercomputer. The simulations reconstruct the chain of events by which a stellar core, similar to the remnant of a tidally disrupted red giant star, might evolve under the gravitational tides of a massive black hole.

"Calculating the messy interplay between hydrodynamics and gravity is feasible on a human timescale only with a supercomputer," Cheng said. "Because we have control over this virtual experiment and can repeat it, fast forward, or rewind as needed, we can examine the tidal disruption process from many perspectives. This in turn allows us to determine and quantify the most important physical processes at play."

The research shows how supercomputer simulations complement and constrain theory and observation.

"There are many situations in astrophysics where we cannot get insight into a sequence of events that played out without simulations. We cannot stand next to the black hole and look at how it accretes gas. So we use simulations to learn about these distant and extreme environments," Bogdanovic said.

One of Bogdanovic's goals is to use the knowledge gained from simulations to decode the signatures of observed tidal disruption events.

"The most recent data on tidal disruption events is already outpacing theoretical understanding and calling for the development of a new generation of models," she explained. "The new, better quality data indicates that there is a great diversity among the tidal disruption candidates. This is contrary to our perception, based on earlier epochs of observation, that they are a relatively uniform class of events. We have yet to understand what causes these differences in observational appearance, and computer simulations are guaranteed to be an important part of this journey."

Investigators
Roseanne Cheng
Pau Amaro-Seoane
Tamara Bogdanovic

THE RUNNING SPIRAL

FROM:  NASA 
Life Is Too Fast, Too Furious for Runaway Galaxy

The spiral galaxy ESO 137-001 looks like a dandelion caught in a breeze in this new composite image from the Chandra X-ray Observatory and  the Hubble Space Telescope.

The galaxy is zooming toward the upper left of this image, in between other galaxies in the Norma cluster located over 200 million light-years away. The road is harsh: intergalactic gas in the Norma cluster is sparse, but so hot at 180 million degrees Fahrenheit that it glows in X-rays detected by Chandra (blue).
The spiral plows through the seething intra-cluster gas so rapidly - at nearly 4.5 million miles per hour - much of its own gas is caught and torn away. Astronomers call this "ram pressure stripping." The galaxy's stars remain intact due to the binding force of their gravity.

Tattered threads of gas, the blue jellyfish-tendrils sported by ESO 137-001 in the image, illustrate the process. Ram pressure has strung this gas away from its home in the spiral galaxy and out over intergalactic space. Once there, these strips of gas have erupted with young, massive stars, which are pumping out light in vivid blues and ultraviolet.

The brown, smoky region near the center of the spiral is being pushed in a similar manner, although in this case it is small dust particles, and not gas, that are being dragged backwards by the intra-cluster medium.

From a star-forming perspective, ESO 137-001 really is spreading its seeds into space like a dandelion in the wind. The stripped gas is now forming stars. However, the galaxy, drained of its own star-forming fuel, will have trouble making stars in the future. Through studying this runaway spiral, and other galaxies like it, astronomers hope to gain a better understanding of how galaxies form stars and evolve over time.

The image is also decorated with hundreds of stars from within the Milky Way. Though not connected in the slightest to ESO 137-001, these stars and the two reddish elliptical galaxies contribute to a vibrant celestial vista.  Credit:  NASA.

EUROPA AND THE SEARCH FOR WATER

FROM:  NASA 
This reprojection of the official USGS basemap of Jupiter's moon Europa is centered at the estimated source region for potential water vapor plumes that might have been detected using the Hubble Space Telescope. The view is centered at -65 degrees latitude, 183 degrees longitude. In addition to the plume source region, the image also shows the hemisphere of Europa that might be affected by plume deposits. This map is composed of images from NASA's Galileo and Voyager missions. The black region near the south pole results from gaps in imaging coverage. Image Credit: NASA/JPL-Caltech/SETI Institute.

NSF ON EARLY COSMOS AND HEAVY METAL

FROM:  NATIONAL SCIENCE FOUNDATION 
Heavy metal in the early cosmos
Simulations shed light on the formation and explosion of stars in the earliest galaxies

Ab initio: "From the beginning."

It is a term that's used in science to describe calculations that rely on established mathematical laws of nature, or "first principles," without additional assumptions or special models.

But when it comes to the phenomena that Milos Milosavljevic is interested in calculating, we're talking really ab initio, as in: from the beginning of time onward.

Things were different in the early eons of the universe. The cosmos experienced rapid inflation; electrons and protons floated free from each other; the universe transitioned from complete darkness to light; and enormous stars formed and exploded to start a cascade of events leading to our present-day universe.

Working with Chalence Safranek-Shrader and Volker Bromm at the University of Texas at Austin, Milosavljevic recently reported the results of several massive numerical simulations charting the forces of the universe in its first hundreds of millions of years using some of the world's most powerful supercomputers, including the National Science Foundation-supported Stampede, Lonestar and Ranger systems at the Texas Advanced Computing Center.

The results, described in the Monthly Notices of the Royal Astronomical Society in January 2014, refine how the first galaxies formed, and in particular, how metals in the stellar nurseries influenced the characteristics of the stars in the first galaxies.

"The universe formed at first with just hydrogen and helium," said Milosavljevic. "But then the very first stars cooked metals and after those stars exploded, the metals were dispersed into ambient space."

Eventually the ejected metals fell back into the gravitational fields of the dark matter haloes, where they formed the second generation of stars. However, the first generation of metals ejected from supernovae did not mix in space uniformly.

"It's as if you have coffee and cream but you don't stir it, and you don't wait for a long enough time," he explained. "You would drink some cream and coffee but not coffee with cream. There will be thin sheets of coffee and cream."

According to Milosavljevic, subtle effects like these governed the evolution of early galaxies. Some stars formed that were rich in metals, while others were metal-poor. Generally there was a spread in stellar chemical abundances because of the incomplete mixing.

Another factor that influenced the evolution of galaxies was how the heavier elements emerged from the originating blast. Instead of the neat spherical blast wave that researchers presumed before, the ejection of metals from a supernova was most likely a messy process, with blobs of shrapnel shooting in every direction.

"Modeling these blobs properly is very important for understanding where metals ultimately go," Milosavljevic said.

Predicting future observations

In astronomical terms, early in the universe translates to very far away. Those fugitive first galaxies are unbelievably distant from us now, if they haven't been incorporated into more recently-formed galaxies already. But many believe the early galaxies lie at a distance that we will be able to observe with the James Webb Space Telescope (JWST), set to launch in 2018. This makes Milosavljevic and his team's cosmological simulations timely.

"Should the James Webb Space Telescope integrate the image in one spot for a long time or should it mosaic its survey to look at a larger area?" Milosavljevic said. "We want to recommend strategies for the JWST."

Telescopes on the ground will perform follow-up studies of the phenomena that JWST detects. But to do so, scientists need to know how to interpret JWST's observations and develop a protocol for following up with ground-based telescopes.

Milosavljevic and others' cosmological simulations will help determine where the Space Telescope will look, what it will look for, and what to do once a given signal is observed.

Distant objects, born at a given moment in cosmic history, have tell-tale signature--spectra or light curves. Like isotopes in carbon dating, these signatures help astronomers recognize and date phenomenon in deep space. In the absence of any observations, simulations are the best way of predicting these light signatures.

"We are anticipating observations until they become available in the future," he said.

If done correctly, such simulations can mimic the dynamics of the universe over billions of years, and emerge with results that look something like what we see... or hope to see with new farther-reaching telescopes.

"This is a really exciting time for the field of cosmology," astronomer and Nobel Laureate Saul Perlmutter said in his keynote address at the Supercomputing '13 conference in November. "We are now ready to collect, simulate and analyze the next level of precision data... There's more to high performance computing science than we have yet accomplished."

Understanding our place in the universe

In addition to the practical goals of guiding the James Webb Space Telescope, the effort to understand these very early stars in the first galaxies has another function: to help tell the story of how our solar system came to be.

The current state of the universe is determined by the violent evolutions of the generations of stars that came before. Each generation of stars (or "population," in astronomy terms) has its own characteristics, based on the environment it was created in.

The Population III stars, the earliest that formed, are thought to have been massive and gaseous, consisting initially of hydrogen and helium. These stars ultimately collapsed and seeded new, smaller, stars that clustered into the first galaxies. These in turn exploded again, creating the conditions of Population I stars like our own, chock full of materials that enable life. How stars and galaxies evolved from one stage to another is still a much-debated question.

"All of this was happening when the universe was very young, only a few hundred million years old," Milosavljevic said. "And to make things more difficult, stars--like people--change. Every hundred million years, every 10 million years--it's like a kid growing up, all the time something new is happening."

Simulating the universe from birth to its current age, Milosavljevic and his team's investigations help disentangle how galaxies changed over time, and provide a better sense of what came before us and how we came to be.

Said Nigel Sharp, program director in the Division of Astronomical Sciences at the National Science Foundation: "These are novel studies using methods often ignored by other efforts, but of great importance as they impact so much of what happens in later cosmology and galaxy studies."
Investigators
Volker Bromm
Milos Milosavljevic
Chalence Safranek-Shrader
Related Institutions/Organizations
University of Texas at Austin
Locations
Austin , Texas

THE FLAT GALAXY

FROM:  NASA/HUBBLE GALAXY 
Hubble Eyes Galaxy as Flat as a Pancake

Located some 25 million light-years away, this new Hubble image shows spiral galaxy ESO 373-8. Together with at least seven of its galactic neighbors, this galaxy is a member of the NGC 2997 group. We see it side-on as a thin, glittering streak across the sky, with all its contents neatly aligned in the same plane.
We see so many galaxies like this — flat, stretched-out pancakes — that our brains barely process their shape. But let us stop and ask: Why are galaxies stretched out and aligned like this?

Try spinning around in your chair with your legs and arms out. Slowly pull your legs and arms inwards, and tuck them in against your body. Notice anything? You should have started spinning faster. This effect is due to conservation of angular momentum, and it’s true for galaxies, too.

This galaxy began life as a humungous ball of slowly rotating gas. Collapsing in upon itself, it spun faster and faster until, like pizza dough spinning and stretching in the air, a disc started to form. Anything that bobbed up and down through this disk was pulled back in line with this motion, creating a streamlined shape.
Angular momentum is always conserved — from a spinning galactic disk 25 million light-years away from us, to any astronomer, or astronomer-wannabe, spinning in an office chair.  Image Credit: NASA/Hubble

UNDERSTANDING A STAR'S SURFACE AND THE EXTREME FORCES OF NATURE

ILLUSTRATION FROM:  NASA:  A neutron star is the densest object astronomers can observe directly, crushing half a million times Earth's mass into a sphere about 12 miles across, or similar in size to Manhattan Island, as shown in this illustration.
Credit: NASA's Goddard Space Flight Center
Neutron Stars’ X-ray 


STORY FROM:  LOS ALAMOS NATIONAL LABORATORY 

Superbursts Mystify, Inspire Los Alamos Scientists

New neutrino cooling theory changes understanding of stars’ surface

LOS ALAMOS, N.M., Dec. 6, 2013—Massive X-ray superbursts near the surface of neutron stars are providing a unique window into the operation of fundamental forces of nature under extreme conditions.

“Scientists are intrigued by what exactly powers these massive explosions, and understanding this would yield important insights about the fundamental forces in nature, especially on the astronomical/cosmological scale,” said Peter Moller of Los Alamos National Laboratory’s Theoretical Division.



A neutron star is created during the death of a giant star more massive than the sun, compressed to a tiny size but with gravitational fields exceeded only by those of black holes. And in the intense, neutron-rich environment, nuclear reactions cause strong explosions that manifest themselves as X-ray bursts and the X-ray superbursts that are more rare and 1000 times more powerful.

Los Alamos researchers and former postdocs contributed to the paper “Strong neutrino cooling by cycles of electron capture and beta decay in neutron star crusts” that was published in Nature’s online edition of Dec. 1, 2013.
The importance of discovering an unknown energy source of titanic magnitude in the outermost layers of accreting neutron star surfaces is heightened by the unresolved issue of neutrino masses, the recent discovery of the Higgs boson and the fact that highly-neutron-rich nuclei with low-lying states enable “Weak Interactions,” prominent in stellar explosions. (The weak nuclear force is one of four fundamental sources, such as gravity, which interacts with the neutrinos; it is responsible for some types of radioactive decay.)

These hitherto celestially operative nuclei are expected to be within the experimental reach of the Facility for Rare Isotope Beams (FRIB), a proposed user facility at Michigan State University funded by the U.S. Department of Energy Office of Science.

“The terrestrial experimental study of Weak Interactions in highly deformed, neutron-rich nuclei that FRIB can potentially provide is lent support by this ground-breaking Nature letter, since Los Alamos has been one of the few homes to theoretical studies of deformed nuclei and their role in astrophysics, and remains so to this day,” said Moller, who coauthored the paper with a multidisciplinary team including former Los Alamos postdoctoral researchers Sanjib Gupta, now a faculty member at the Indian Institute of Technology (IIT), Ropar and Andrew Steiner, now a research assistant professor at INT, Seattle.

Previously a common assumption was that that the energy released in these radioactive decays would power the X-ray superburst explosions. This was based on simple models of nuclear beta-decay, sometimes postulating the same decay properties for all nuclei. It turns out, however, that it is of crucial importance to develop computer models that realistically describe the shape of each individual nuclide since they are not all spherical.

At Los Alamos scientists have carried out detailed calculations of the specific, individual beta-decay properties of thousands of nuclides, all with different decay properties, and created databases with these calculated properties.

The databases are then used at MSU as input into models that trace the decay pathways with the passage of time in accreting neutron stars and compute the total energy that is released in these reactions.

The new, unexpected result is that so much energy escapes by neutrino emission that the remaining energy released in the beta decays is not sufficient to ignite the X-ray superbursts that are observed. Thus the superbursts’ origin has now become a puzzle.

Solving the puzzle will require that we calculate in detail the consequences of shapes of neutron-rich nuclei, the authors said, and it requires that they simultaneously analyze the role played by neutrinos in neutron star X-ray bursts whose energetic magnitudes are exceeded only by explosions in the nova/supernova class.

The strong nuclear deformations that formed the basis for the neutrino cooling in neutron star crusts also play a role in a number of astrophysical settings, and have been taken into account in studies of supernovae explosions and subsequent collapses, funded by Los Alamos’ Laboratory Directed Research and Development (LDRD) programs.

Nuclear-structure databases valued worldwide

The large databases compiled by use of these and other nuclear-structure models are also used in several other Los Alamos programs. For example in modeling nuclear-reactor behavior, researchers have had to take into account beta-decay both because delayed neutrons are emitted, which governs the criticality of the reactor, and because it generates heat, just as in the neutron star.

Another current application is in nuclear non-proliferation programs. One method for detecting clandestine nuclear material in cargo shipments is to bombard cargoes with a small number of neutrons. If emission of delayed neutrons is detected after neutron bombardment, scientists have a sure signature of fissile nuclear material. The theoretical databases compiled at Los Alamos are not just used internally but are also part of nuclear-structure databases maintained by the International Atomic Energy Agency.

The authors, an international team

The authors on the paper are Hendrik Schatz from MSU; Sanjib Gupta from IIT Ropar; Peter Mller from LANL; Mary Beard and Michael Wiescher from the University of Notre Dame; Edward F. Brown, Alex T. Deibel, Laurens Keek, and Rita Lau from MSU; Leandro R. Gasques from the Universidade de Sao Paulo; William Raphael Hix from Oak Ridge National Laboratory and the University of Tennessee; and Andrew W. Steiner from the University of Washington.

LADEE READY TO COLLECT LUNAR DATA

FROM:  NASA 
Right:  An Artist’s concept of NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft in orbit above the moon as dust scatters light during the lunar sunset.  Image Credit-NASA AMES- Dana Berry

NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) is ready to begin collecting science data about the moon.

On Nov. 20, the spacecraft successfully entered its planned orbit around the moon's equator -- a unique position allowing the small probe to make frequent passes from lunar day to lunar night. This will provide a full scope of the changes and processes occurring within the moon's tenuous atmosphere.
LADEE now orbits the moon about every two hours at an altitude of eight to 37 miles (12-60 kilometers) above the moon's surface. For about 100 days, the spacecraft will gather detailed information about the structure and composition of the thin lunar atmosphere and determine whether dust is being lofted into the lunar sky.

"A thorough understanding of the characteristics of our lunar neighbor will help researchers understand other small bodies in the solar system, such as asteroids, Mercury, and the moons of outer planets," said Sarah Noble, LADEE program scientist at NASA Headquarters in Washington.

Scientists also will be able to study the conditions in the atmosphere during lunar sunrise and sunset, where previous crewed and robotic missions detected a mysterious glow of rays and streamers reaching high into the lunar sky.
“This is what we’ve been waiting for – we are already seeing the shape of things to come,” said Rick Elphic, LADEE project scientist at NASA's Ames Research Center in Moffett Field, Calif.

On Nov. 20, flight controllers in the LADEE Mission Operations Center at Ames confirmed LADEE performed a crucial burn of its orbit control system to lower the spacecraft into its optimal position to enable science collection. Mission managers will continuously monitor the spacecraft's altitude and make adjustments as necessary.

"Due to the lumpiness of the moon's gravitational field, LADEE's orbit requires significant maintenance activity with maneuvers taking place as often as every three to five days, or as infrequently as once every two weeks," said Butler Hine, LADEE project manager at Ames. "LADEE will perform regular orbital maintenance maneuvers to keep the spacecraft’s altitude within a safe range above the surface that maximizes the science return."

In addition to science instruments, the spacecraft carried the Lunar Laser Communications Demonstration, NASA's first high-data-rate laser communication system. It is designed to enable satellite communication at rates similar to those of high-speed fiber optic networks on Earth. The system was tested successfully during the commissioning phase of the mission, while LADEE was still at a higher altitude.

LADEE was launched Sept. 6 on a U.S. Air Force Minotaur V, an excess ballistic missile converted into a space launch vehicle and operated by Orbital Sciences Corp. of Dulles, Va. LADEE is the first spacecraft designed, developed, built, integrated and tested at Ames. It also was the first probe launched beyond Earth orbit from NASA's Wallops Flight Facility on the Virginia coast.
NASA's Science Mission Directorate in Washington funds the LADEE mission. Ames manages the overall mission and serves as a base for mission operations and real-time control of the probe. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the science instruments and technology demonstration payload, the science operations center and overall mission support. NASA's Marshall Space Flight Center in Huntsville, Ala., manages LADEE within the Lunar Quest Program Office.

MARS MOSAIC

FROM: NASA
Panoramic View From Near 'Point Lake' in Gale Crater, Sol 106

This panorama is a mosaic of images taken by the Mast Camera (Mastcam) on the NASA Mars rover Curiosity during the 106th Martian day, or sol, of the mission (Nov. 22, 2012). The rover was near a location called "Point Lake" for an overlook of a shallow depression called "Yellowknife Bay" which is in the left third of this scene, in the middle distance.

The image spans 360 degrees, with south at the center. It has been white-balanced to show what the rocks and soils in it would look like if they were on Earth.

Image Credit-NASA-JPL-Caltech-Malin Space Science Systems

CASSIOPEIA A: THE REMAINS OF A SUPERNOVA

 

FROM: NASA

Sizzling Remains of a Dead Star

This new view of the historical supernova remnant Cassiopeia A, located 11,000 light-years away, was taken by NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR. Blue indicates the highest energy X-ray light, where NuSTAR has made the first resolved image ever of this source. Red and green show the lower end of NuSTAR's energy range, which overlaps with NASA's high-resolution Chandra X-ray Observatory.

Light from the stellar explosion that created Cassiopeia A is thought to have reached Earth about 300 years ago, after traveling 11,000 years to get here. While the star is long dead, its remains are still bursting with action. The outer blue ring is where the shock wave from the supernova blast is slamming into surrounding material, whipping particles up to within a fraction of a percent of the speed of light. NuSTAR observations should help solve the riddle of how these particles are accelerated to such high energies

X-ray light with energies between 10 and 20 kiloelectron volts are blue; X-rays of 8 to 10 kiloelectron volts are green; and X-rays of 4.5 to 5.5 kiloelectron volts are red.

The starry background picture is from the Digitized Sky Survey.


Image credit: NASA/JPL-Caltech/DSS

LIBRARY OF CONGRESS ACQUIRES ASTRONOMER CARL SAGAN'S PAPERS

FROM U.S. LIBRARY OF CONGRESS

The Library of Congress has acquired the personal papers of American astronomer, astrobiologist and science communicator Carl Sagan (1934-1996). A celebrated scientist, educator, television personality and prolific author, Sagan was a consummate communicator who bridged the gap between academe and popular culture.

The Sagan collection has come to the Library through the generosity of writer, producer and director Seth MacFarlane, and is officially designated The Seth MacFarlane Collection of the Carl Sagan and Ann Druyan Archive.

The collection comprises approximately 800 boxes of materials that document Sagan’s life and work and includes his extensive correspondence with scientific colleagues and other important figures of the 20th century. It also includes book drafts, publications files, "idea files" on various subjects, records of various symposia, NASA files and academic files covering the years he taught at Cornell University. Among the personal files are his birth announcement, handwritten notebooks of his earliest thoughts and grammar-school report cards. In addition to manuscript materials, the collection includes photographs, audiotapes and videocassettes. Researchers and scholars will be able to use the collection once it has been fully processed by the Library’s archivists.

"We are honored to preserve and make accessible to researchers the legacy of Carl Sagan, a man who devoted his life to the study of the universe," said Librarian of Congress James H. Billington. "The Sagan papers are a rich addition to the Library’s already-outstanding collection of science manuscripts and other materials from such prominent figures as Benjamin Franklin, Thomas Edison, Alexander Graham Bell, Sigmund Freud, J. Robert Oppenheimer and E.O. Wilson."

"Carl was the exemplar of the citizen scientist," said Druyan, Sagan’s long time professional collaborator and his widow. "For him, the values of democracy and science were intertwined. I can think of no more fitting home for his papers than the nation’s library. Thanks to Seth, Carl’s prodigious life’s work will endure to awaken future generations to the wonders of the scientific perspective."

Sagan and Druyan co-wrote several books, and the "Cosmos" television series and were co-creators of the motion picture, "Contact." Druyan was the creative director of NASA’s Voyager Interstellar Record Project (http://voyager.jpl.nasa.gov/spacecraft/goldenrec.html).

"The work of Carl Sagan has been a profound influence in my life, and the life of every individual who recognizes the importance of humanity's ongoing commitment to the exploration of our universe," said MacFarlane. "The continuance of our journey outward into space should always occupy some part of our collective attention, regardless of whatever Snooki did last week."

MacFarlane is the creative force behind the television shows "Family Guy," "American Dad!" and "The Cleveland Show." "Family Guy" has garnered four Emmys and seven Emmy nominations, including one in the Outstanding Comedy Series category. MacFarlane makes his directorial feature film debut on June 29, 2012, with the live-action and computer-generated comedy, "Ted." His orchestral/big band album, "Music Is Better Than Words," debuted at number one on the iTunes Jazz charts on Sept 27, 2011, and received two Grammy nominations, including Best Traditional Pop Vocal Album.

MacFarlane has teamed up with Sagan’s original creative collaborators—writer/producer Ann Druyan and astrophysicist Steven Soter—to conceive a 13-part "docu-series" that will serve as a successor to the Emmy and Peabody Award-winning original series, "Cosmos." Produced in conjunction with FOX and the National Geographic Channel, "Cosmos: A Space-Time Odyssey" will explore how human beings began to comprehend the laws of nature and find their place in space and time. By exploring never-before-told stories of the heroic quest for knowledge, the series aims to take viewers to other worlds and travel across the universe for a vision of the cosmos on the grandest scale.

Carl Sagan earned a Pulitzer Prize for his bestseller, "The Dragons of Eden: Speculation on the Evolution of Human Intelligence." His science-fiction novel, "Contact," became both a bestseller and a feature film. It is estimated that more than a billion people around the world have viewed his popular PBS show, "Cosmos."

Sagan specialized in planetary astronomy. His early work on planetary surfaces and atmospheres is considered pioneering, and he made landmark contributions to NASA’s Mariner, Pioneer, Apollo, Galileo, Viking and Voyager space-exploration programs. For his unique contributions, he was awarded medals for Distinguished Scientific Achievement and Public Service from NASA, the National Science Foundation and the National Academy of Sciences.

A staunch advocate of the scientific method, Sagan was known for his research on the possibilities of extraterrestrial life, for his research and campaigns of public education on the dangers of global warming and the "nuclear winter" that could result from a nuclear war.

To examine Sagan’s legacy as a role model for future American scientists, the Library of Congress will sponsor a "Summit on Science Education" late next year. The event, which will bring together scientists, educators, policy-makers and students, will underscore Sagan’s conviction that it is critical to understand and appreciate the centrality of science in the everyday lives of Americans and to create a renewed national consciousness about preparing the next generation of scientists.

The Library of Congress, the nation’s oldest federal cultural institution and the largest library in the world, holds more than 151 million items in various languages, disciplines, and formats. The Library seeks to spark imagination and creativity and to further human understanding and wisdom by providing access to knowledge through its magnificent collections, programs, publications and exhibitions. Many of the Library’s rich resources can be accessed through its website at www.loc.gov.