May 24 2016
From The Space Library
RELEASE 16-054 NASA Telescopes Find Clues For How Giant Black Holes Formed So Quickly
Using data from NASA’s Great Observatories, astronomers have found the best evidence yet for cosmic seeds in the early universe that should grow into supermassive black holes.
Researchers combined data from NASA’s Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer Space Telescope to identify these possible black hole seeds. They discuss their findings in a paper that will appear in an upcoming issue of the Monthly Notices of the Royal Astronomical Society.
“Our discovery, if confirmed, explains how these monster black holes were born,” said Fabio Pacucci of Scuola Normale Superiore (SNS) in Pisa, Italy, who led the study. “We found evidence that supermassive black hole seeds can form directly from the collapse of a giant gas cloud, skipping any intermediate steps.”
Scientists believe a supermassive black hole lies in the center of nearly all large galaxies, including our own Milky Way. They have found that some of these supermassive black holes, which contain millions or even billions of times the mass of the sun, formed less than a billion years after the start of the universe in the Big Bang.
One theory suggests black hole seeds were built up by pulling in gas from their surroundings and by mergers of smaller black holes, a process that should take much longer than found for these quickly forming black holes.
These new findings suggest instead that some of the first black holes formed directly when a cloud of gas collapsed, bypassing any other intermediate phases, such as the formation and subsequent destruction of a massive star.
“There is a lot of controversy over which path these black holes take,” said co-author Andrea Ferrara, also of SNS. “Our work suggests we are narrowing in on an answer, where the black holes start big and grow at the normal rate, rather than starting small and growing at a very fast rate.”
The researchers used computer models of black hole seeds combined with a new method to select candidates for these objects from long-exposure images from Chandra, Hubble, and Spitzer.
The team found two strong candidates for black hole seeds. Both of these matched the theoretical profile in the infrared data, including being very red objects, and also emit X-rays detected with Chandra. Estimates of their distance suggest they may have been formed when the universe was less than a billion years old
“Black hole seeds are extremely hard to find and confirming their detection is very difficult,” said Andrea Grazian, a co-author from the National Institute for Astrophysics in Italy. “However, we think our research has uncovered the two best candidates to date.”
The team plans to obtain further observations in X-rays and the infrared to check whether these objects have more of the properties expected for black hole seeds. Upcoming observatories, such as NASA’s James Webb Space Telescope and the European Extremely Large Telescope will aid in future studies by detecting the light from more distant and smaller black holes. Scientists currently are building the theoretical framework needed to interpret the upcoming data, with the aim of finding the first black holes in the universe.
“As scientists, we cannot say at this point that our model is ‘the one’,” said Pacucci. “What we really believe is that our model is able to reproduce the observations without requiring unreasonable assumptions.”
NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program while the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.
NASA's Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission, whose science operations are conducted at the Spitzer Science Center. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado.
MEDIA ADVISORY M16-058 NASA Astronaut Kate Rubins Available for Interviews Before Space Station Launch
NASA astronaut Kate Rubins will be available for live satellite interviews from Moscow on Wednesday, June 1, before her launch to the International Space Station. She will answer questions about her upcoming mission aboard the world’s only orbiting laboratory from 9-10 a.m. EDT, airing live on NASA Television and streaming on the agency’s website.
Rubins, who was born in Farmington, Connecticut, and raised in Napa, California, is in Moscow for final preparations prior to her launch on June 24. The interviews will be preceded at 8:30 a.m. by 30 minutes of video clips highlighting her training.
To schedule an interview, media must contact Thomas Gerczak at 281-792-7515 or thomas.j.gerczak@nasa.gov no later than 4 p.m. on Friday, May 27. Media participating in the live shots must tune to NTV-3. Satellite tuning information is available at: [[1]]
Rubins will launch to the space station aboard a Soyuz spacecraft from the Baikonur Cosmodrome in Kazakhstan, along with her Expedition 48/49 crewmates, cosmonaut Anatoly Ivanishin of the Russian space agency Roscosmos and astronaut Takuya Onishi of the Japan Aerospace Exploration Agency.
Rubins was selected as an astronaut in 2009, and this will be her first spaceflight.
During her time at the space station, Rubins will participate in several science experiments. Along with physical science, Earth and space science and technology development work, she will conduct biological and human research investigations. Research into sequencing the first genome in microgravity and how the human body’s bone mass and cardiovascular systems are changed by living in space are just two examples of the many experiments in which Rubins may take part.
Rubins received a bachelor’s degree in molecular biology from the University of California, San Diego, and a doctorate in cancer biology from Stanford University. Before joining the astronaut corps in 2009, she worked with the U.S. Army Medical Research Institute of Infectious Diseases and the Centers for Disease Control and Prevention, where she helped develop the first model of smallpox infection. She also headed a laboratory of 14 researchers studying viral diseases that affect Central and West Africa. As part of that work, she researched the gene expression responses of diseases, such as monkeypox and Ebola.
After arriving at the station on June 26, Rubins, Ivanishin and Onishi will join Expedition 48 NASA astronaut Jeff Williams, and Roscosmos cosmonauts Alexey Ovchinin and Oleg Skripochka. They are expected to be at the station for the delivery of the station’s first international docking adapter, which will accommodate the future arrival of U.S. commercial crew spacecraft. A Japanese cargo craft also is planned to launch to the station carrying lithium ion batteries to replace the nickel-hydrogen batteries currently used on the station to store electrical energy generated by the station’s solar arrays.
Rubins is scheduled to return to Earth with Ivanishin and Onishi in October.
NASA Scientist Suggests Possible Link Between Primordial Black Holes and Dark Matter
Dark matter is a mysterious substance composing most of the material universe, now widely thought to be some form of massive exotic particle. An intriguing alternative view is that dark matter is made of black holes formed during the first second of our universe's existence, known as primordial black holes. Now a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, suggests that this interpretation aligns with our knowledge of cosmic infrared and X-ray background glows and may explain the unexpectedly high masses of merging black holes detected last year.
"This study is an effort to bring together a broad set of ideas and observations to test how well they fit, and the fit is surprisingly good," said Alexander Kashlinsky, an astrophysicist at NASA Goddard. "If this is correct, then all galaxies, including our own, are embedded within a vast sphere of black holes each about 30 times the sun's mass."
In 2005, Kashlinsky led a team of astronomers using NASA's Spitzer Space Telescope to explore the background glow of infrared light in one part of the sky. The researchers reported excessive patchiness in the glow and concluded it was likely caused by the aggregate light of the first sources to illuminate the universe more than 13 billion years ago. Follow-up studies confirmed that this cosmic infrared background (CIB) showed similar unexpected structure in other parts of the sky.
In 2013, another study compared how the cosmic X-ray background (CXB) detected by NASA's Chandra X-ray Observatory compared to the CIB in the same area of the sky. The first stars emitted mainly optical and ultraviolet light, which today is stretched into the infrared by the expansion of space, so they should not contribute significantly to the CXB.
Yet the irregular glow of low-energy X-rays in the CXB matched the patchiness of the CIB quite well. The only object we know of that can be sufficiently luminous across this wide an energy range is a black hole. The research team concluded that primordial black holes must have been abundant among the earliest stars, making up at least about one out of every five of the sources contributing to the CIB.
The nature of dark matter remains one of the most important unresolved issues in astrophysics. Scientists currently favor theoretical models that explain dark matter as an exotic massive particle, but so far searches have failed to turn up evidence these hypothetical particles actually exist. NASA is currently investigating this issue as part of its Alpha Magnetic Spectrometer and Fermi Gamma-ray Space Telescope missions.
"These studies are providing increasingly sensitive results, slowly shrinking the box of parameters where dark matter particles can hide," Kashlinsky said. "The failure to find them has led to renewed interest in studying how well primordial black holes -- black holes formed in the universe's first fraction of a second -- could work as dark matter."
Physicists have outlined several ways in which the hot, rapidly expanding universe could produce primordial black holes in the first thousandths of a second after the Big Bang. The older the universe is when these mechanisms take hold, the larger the black holes can be. And because the window for creating them lasts only a tiny fraction of the first second, scientists expect primordial black holes would exhibit a narrow range of masses.
On Sept. 14, gravitational waves produced by a pair of merging black holes 1.3 billion light-years away were captured by the Laser Interferometer Gravitational-Wave Observatory (LIGO) facilities in Hanford, Washington, and Livingston, Louisiana. This event marked the first-ever detection of gravitational waves as well as the first direct detection of black holes. The signal provided LIGO scientists with information about the masses of the individual black holes, which were 29 and 36 times the sun's mass, plus or minus about four solar masses. These values were both unexpectedly large and surprisingly similar.
"Depending on the mechanism at work, primordial black holes could have properties very similar to what LIGO detected," Kashlinsky explained. "If we assume this is the case, that LIGO caught a merger of black holes formed in the early universe, we can look at the consequences this has on our understanding of how the cosmos ultimately evolved."
In his new paper, published May 24 in The Astrophysical Journal Letters, Kashlinsky analyzes what might have happened if dark matter consisted of a population of black holes similar to those detected by LIGO. The black holes distort the distribution of mass in the early universe, adding a small fluctuation that has consequences hundreds of millions of years later, when the first stars begin to form.
For much of the universe's first 500 million years, normal matter remained too hot to coalesce into the first stars. Dark matter was unaffected by the high temperature because, whatever its nature, it primarily interacts through gravity. Aggregating by mutual attraction, dark matter first collapsed into clumps called minihaloes, which provided a gravitational seed enabling normal matter to accumulate. Hot gas collapsed toward the minihaloes, resulting in pockets of gas dense enough to further collapse on their own into the first stars. Kashlinsky shows that if black holes play the part of dark matter, this process occurs more rapidly and easily produces the lumpiness of the CIB detected in Spitzer data even if only a small fraction of minihaloes manage to produce stars.
As cosmic gas fell into the minihaloes, their constituent black holes would naturally capture some of it too. Matter falling toward a black hole heats up and ultimately produces X-rays. Together, infrared light from the first stars and X-rays from gas falling into dark matter black holes can account for the observed agreement between the patchiness of the CIB and the CXB.
Occasionally, some primordial black holes will pass close enough to be gravitationally captured into binary systems. The black holes in each of these binaries will, over eons, emit gravitational radiation, lose orbital energy and spiral inward, ultimately merging into a larger black hole like the event LIGO observed.
"Future LIGO observing runs will tell us much more about the universe's population of black holes, and it won't be long before we'll know if the scenario I outline is either supported or ruled out," Kashlinsky said.
Kashlinsky leads science team centered at Goddard that is participating in the European Space Agency's Euclid mission, which is currently scheduled to launch in 2020. The project, named LIBRAE, will enable the observatory to probe source populations in the CIB with high precision and determine what portion was produced by black holes.
Science Instruments of NASA’s James Webb Space Telescope Successfully Installed
With surgical precision, two dozen engineers and technicians successfully installed the package of science instruments of the James Webb Space Telescope into the telescope structure. The package is the collection of cameras and spectrographs that will record the light collected by Webb’s giant golden mirror.
Inside the world’s largest clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, the team crane-lifted the heavy science instrument package, lowered it into an enclosure on the back of the telescope, and secured it to the telescope.
“Our personnel were navigating a very tight space with very valuable hardware,” said Jamie Dunn, ISIM Manager (ISIM stands for ‘Integrated Science Instrument Module’). “We needed the room to be quiet so if someone said something we would be able to hear them. You listen not only for what other people say, but to hear if something doesn’t sound right.”
Before the procedure, the engineers and technicians had trained with test runs, computer modeling and a mock-up of the instrument package. This is a critical mission operation.
“This is a tremendous accomplishment for our worldwide team,” said John Mather, James Webb Space Telescope Project Scientist and Nobel Laureate. “There are vital instruments in this package from Europe and Canada as well as the US and we are so proud that everything is working so beautifully, 20 years after we started designing our observatory.”
Now that the instruments, mirrors, and telescope structure have been assembled, the combination will go through vibration and acoustic tests in order to ensure the whole science payload will withstand the conditions of launch.
“Designing and building something of this magnitude and complexity, with this amount of new technology, is far from routine,” said Dunn. “While every project has their share of ups and downs, the JWST team has had to work through a lot over the life of this project. The character and dedication of this team is extraordinary, they’ve always recovered brilliantly, and they’ve made many personal sacrifices to get us to this point.”
The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb will study many phases in the history of our universe, including the formation of solar systems capable of supporting life on planets similar to Earth, as well as the evolution of our own solar system. It’s targeted to launch from French Guiana aboard an Ariane 5 rocket in 2018. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
