From The NASA Goddard Space Flight Center: “NASA Goddard Scientists Create Black Hole Jets with NCCS Discover Supercomputer” 

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From The NASA Goddard Space Flight Center


Creating Black Hole Jets With a NASA Supercomputer.
New simulations carried out on the NASA Center for Climate Simulation (NCCS) Discover supercomputer show how weaker, low-luminosity jets produced by a galaxy’s monster black hole interact with their galactic environment. Because these jets are more difficult to detect, the simulations help astronomers link these interactions to features they can observe, such as various gas motions and optical and X-ray emissions. Video by NASA’s Goddard Space Flight Center.

Leveraging the NASA Center for Climate Simulation (NCCS), NASA Goddard Space Flight Center scientists ran 100 simulations exploring jets — narrow beams of energetic particles — that emerge at nearly light speed from supermassive black holes. These behemoths sit at the centers of active, star-forming galaxies like our own Milky Way galaxy, and can weigh millions to billions of times the mass of the Sun.

As jets and winds flow out from these active galactic nuclei (AGN), they “regulate the gas in the center of the galaxy and affect things like the star-formation rate and how the gas mixes with the surrounding galactic environment,” explained study lead Ryan Tanner, a postdoc in NASA Goddard’s X-ray Astrophysics Laboratory.

“For our simulations, we focused on less-studied, low-luminosity jets and how they determine the evolution of their host galaxies.” Tanner said. He collaborated with X-ray Astrophysics Laboratory astrophysicist Kimberly Weaver on the computational study, which appears in The Astronomical Journal [below].

Observational evidence for jets and other AGN outflows first came from radio telescopes and later NASA and European Space Agency X-ray telescopes. Over the past 30 to 40 years, astronomers including Weaver have pieced together an explanation of their origin by connecting optical, radio, ultraviolet, and X-ray observations (see the next image below). “High-luminosity jets are easier to find because they create massive structures that can be seen in radio observations,” Tanner explained. “Low-luminosity jets are challenging to study observationally, so the astronomy community does not understand them as well.”

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These images show the diversity of black hole jets. Left: NGC 1068, one of the nearest and brightest galaxies (green and red) with a rapidly growing supermassive black hole, powers a jet (blue) much smaller than the galaxy itself. Image by NASA/CXC/MIT/C.Canizares, D.Evans et al. (X-ray); NASA/STScI (optical); and NSF/NRAO/VLA (radio). Right: The galaxy
Centaurus A reveals particle jets extending far above and below the galaxy’s disk. Image by ESO/WFI (optical); MPIfR/ESO/APEX/A.Weiss et al. (submillimeter); and NASA/CXC/CfA/R. Kraft et al. (X-ray).

Enter NASA supercomputer-enabled simulations. For realistic starting conditions, Tanner and Weaver used the total mass of a hypothetical galaxy about the size of the Milky Way. For the gas distribution and other AGN properties, they looked to spiral galaxies such as NGC 1386, NGC 3079, and NGC 4945.

Tanner modified the Athena astrophysical hydrodynamics code to explore the impacts of the jets and gas on each other across 26,000 light-years of space, about half the radius of the Milky Way. From the full set of 100 simulations, the team selected 19 — which consumed 800,000 core hours on the NCCS Discover supercomputer — for publication.

“Being able to use NASA supercomputing resources allowed us to explore a much larger parameter space than if we had to use more modest resources,” Tanner said. “This led to uncovering important relationships that we could not discover with a more limited scope.”

The simulations uncovered two major properties of low-luminosity jets:

They interact with their host galaxy much more than high-luminosity jets.
They both affect and are affected by the interstellar medium within the galaxy, leading to a greater variety of shapes than high-luminosity jets.

“We have demonstrated the method by which the AGN impacts its galaxy and creates the physical features, such as shocks in the interstellar medium, that we have observed for about 30 years,” Weaver said. “These results compare well with optical and X-ray observations. I was surprised at how well theory matches observations and addresses longstanding questions I have had about AGN that I studied as a graduate student, like NGC 1386! And now we can expand to larger samples.”

Science paper:
The Astronomical Journal
See the science paper for instructive material with images and tables.

See the full article here.

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


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NASA/Goddard Campus

NASA’s Goddard Space Flight Center, Greenbelt, MD is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

GSFC also operates two spaceflight tracking and data acquisition networks (the NASA Deep Space Network and the Near Earth Network); develops and maintains advanced space and Earth science data information systems, and develops satellite systems for the National Oceanic and Atmospheric Administration.

GSFC manages operations for many NASA and international missions including the NASA/ESA Hubble Space Telescope; the Explorers Program; the Discovery Program; the Earth Observing System; INTEGRAL; MAVEN; OSIRIS-REx; the Solar and Heliospheric Observatory ; the Solar Dynamics Observatory; Tracking and Data Relay Satellite System ; Fermi; and Swift. Past missions managed by GSFC include the Rossi X-ray Timing Explorer (RXTE), Compton Gamma Ray Observatory, SMM, COBE, IUE, and ROSAT. Typically, unmanned Earth observation missions and observatories in Earth orbit are managed by GSFC, while unmanned planetary missions are managed by the Jet Propulsion Laboratory (JPL) in Pasadena, California.

Goddard is one of four centers built by NASA since its founding on July 29, 1958. It is NASA’s first, and oldest, space center. Its original charter was to perform five major functions on behalf of NASA: technology development and fabrication; planning; scientific research; technical operations; and project management. The center is organized into several directorates, each charged with one of these key functions.

Until May 1, 1959, NASA’s presence in Greenbelt, MD was known as the Beltsville Space Center. It was then renamed the Goddard Space Flight Center (GSFC), after Robert H. Goddard. Its first 157 employees transferred from the United States Navy’s Project Vanguard missile program, but continued their work at the Naval Research Laboratory in Washington, D.C., while the center was under construction.

Goddard Space Flight Center contributed to Project Mercury, America’s first manned space flight program. The Center assumed a lead role for the project in its early days and managed the first 250 employees involved in the effort, who were stationed at Langley Research Center in Hampton, Virginia. However, the size and scope of Project Mercury soon prompted NASA to build a new Manned Spacecraft Center, now the Johnson Space Center, in Houston, Texas. Project Mercury’s personnel and activities were transferred there in 1961.

The Goddard network tracked many early manned and unmanned spacecraft.

Goddard Space Flight Center remained involved in the manned space flight program, providing computer support and radar tracking of flights through a worldwide network of ground stations called the Spacecraft Tracking and Data Acquisition Network (STDN). However, the Center focused primarily on designing unmanned satellites and spacecraft for scientific research missions. Goddard pioneered several fields of spacecraft development, including modular spacecraft design, which reduced costs and made it possible to repair satellites in orbit. Goddard’s Solar Max satellite, launched in 1980, was repaired by astronauts on the Space Shuttle Challenger in 1984. The Hubble Space Telescope, launched in 1990, remains in service and continues to grow in capability thanks to its modular design and multiple servicing missions by the Space Shuttle.

Today, the center remains involved in each of NASA’s key programs. Goddard has developed more instruments for planetary exploration than any other organization, among them scientific instruments sent to every planet in the Solar System. The center’s contribution to the Earth Science Enterprise includes several spacecraft in the Earth Observing System fleet as well as EOSDIS, a science data collection, processing, and distribution system. For the manned space flight program, Goddard develops tools for use by astronauts during extra-vehicular activity, and operates the Lunar Reconnaissance Orbiter, a spacecraft designed to study the Moon in preparation for future manned exploration.

The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs.] NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.