A Galaxy-scale Fountain of Cold Molecular Gas Pumped by a Black Hole

An image of the bright cluster galaxy Abell 2597 in the X-ray (blue), hydrogen line emission (red), and optical (yellow). Astronomers using multi-wavelength observations from the millimeter to the X-ray have concluded, in agreement with predictions, that this galaxy is both accreting gas from its surroundings and ejecting material out from its supermasssive black hole, thus acting like a cosmic fountain. Credit: X-ray: NASA/CXC/Michigan State Univ/G.Voit et al; Optical: NASA/STScI & DSS; H-alpha: Carnegie Obs./Magellan/W.Baade Telescope/U.Maryland/M.McDona

Most galaxies lie in clusters containing from a few to thousands of other galaxies. Our Milky Way, for example, belongs to the Local Group cluster of about fifty galaxies whose other large member, the Andromeda galaxy, is about 2.3 million light-years away. Clusters are the most massive gravitationally bound objects in the universe and form (according to current ideas) in a “bottoms-up” fashion with smaller structures developing first and with dark matter playing an important role. Exactly how they grow and evolve, however, depends on several competing physical processes including the behavior of the hot intracluster gas.

The galaxy Abell 2597 lies near the center of a cluster about one billion light-years away in the midst of a hot nebula (tens of millions of degrees) of cluster gas. Astronomers have long theorized that intergalactic matter like the plasma around Abell 2597 can fall onto galaxies, cool, and provide fresh material for the galaxy’s star formation. They have, however, also discovered the opposite activity: galaxies’ central supermassive black holes are ejecting jets of material back out into the hot intracluster medium. CfA astronomers Grant Tremblay, Paul Nulsen, Esra Bulbul, Laurence David, Bill Forman, Christine Jones, Ralph Kraft, Scott Randall, and John ZuHone led a large team of colleagues studying the behavior of the hot gas and these competing processes in Abell 2597 using a wide range of observations including new and archival ALMA millimeter observations, optical spectroscopy, and deep Chandra X-Ray Observatory images.
The sensitive and wide-ranging datasets enabled the scientists to probe the thermodynamic character and motions of the hot gas (including both infall and outflow streams), the cold, star forming dust clouds in the galaxy, and the relative spatial arrangement of all these ingredients. They find detailed support for the models, including both infall of hot material into the galaxy and its subsequent conversion into new stars and as well the outflow of gas driven by jets from the central supermassive black hole. They show that the warm and cold material are actually found together in this galaxy (although they are of different densities), with clouds of cold gas likely feeding the black hole and apparently coupling to the powerful jets ejected from the nucleus. The result is that the molecular and ionized nebula at the heart of Abell 2597 is what they term a galaxy-scale “fountain:” cold gas drains into the reservoir created by the presence of the black hole at the center, and this powers outflowing jets that, in turn, later cool and sink, raining back down. Because the outflowing material does not move quickly enough to escape the galaxy’s gravity, they conclude that this dramatic galactic fountain seems likely to be long-lived. It may also be a common occurrence in these massive clusters, helping to explain the cosmic evolution of galaxies.


“A Galaxy-scale Fountain of Cold Molecular Gas Pumped by a Black Hole,” G. R. Tremblay et al. ApJ 865, 13, 2018.

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Exploding Stars Make Key Ingredient in Sand, Glass

This image of supernova remnant G54.1+0.3 includes radio, infrared and X-ray light. 

Credit: NASA/JPL-Caltech/CXC/ESA/NRAO/J. Rho (SETI Institute)› Full image and caption
We are all, quite literally, made of star dust. Many of the chemicals that compose our planet and our bodies were formed directly by stars. Now, a new study using observations by NASA’s Spitzer Space Telescope reports for the first time that silica – one of the most common minerals found on Earth – is formed when massive stars explode.
Look around you right now and there’s a good chance you will see silica (silicon dioxide, SiO2) in some form. A major component of many types of rocks on Earth, silica is used in industrial sand-and-gravel mixtures to make concrete for sidewalks, roads and buildings. One form of silica, quartz, is a major component of sand found on beaches along the U.S. coasts. Silica is a key ingredient in glass, including plate glass for windows, as well as fiberglass. Most of the silicon used in electronic devices comes from silica.
In total, silica makes up about 60 percent of Earth’s crust. Its widespread presence on Earth is no surprise, as silica dust has been found throughout the universe and in meteorites that predate our solar system. One known source of cosmic dust is AGB stars, or stars with about the mass of the Sun that are running out of fuel and puff up to many times their original size to form a red giant star. (AGB stars are one type of red giant star.) But silica is not a major component of AGB star dust, and observations had not made it clear if these stars could be the primary producer of silica dust observed throughout the universe.
The new study reports the detection of silica in two supernova remnants, called Cassiopeia A and G54.1+0.3. A supernova is a star much more massive than the Sun that runs out of the fuel that burns in its core, causing it to collapse on itself. The rapid in-fall of matter creates an intense explosion that can fuse atoms together to create “heavy” elements, like sulfur, calcium and silicon.

Chemical Fingerprints

To identify silica in Cassiopeia A and G54.1+0.3, the team used archival data from Spitzer’s IRS instrument and a technique called spectroscopy, which takes light and reveals the individual wavelengths that compose it. (You can observe this effect when sunlight passes through a glass prism and produces a rainbow: The different colors are the individual wavelengths of light that are typically blended together and invisible to the naked eye.)
Chemical elements and molecules each emit very specific wavelengths of light, meaning they each have a distinct spectral “fingerprint” that high-precision spectrographs can identify. In order to discover the spectral fingerprint of a given molecule, researchers often rely on models (typically done with computers) that re-create the molecule’s physical properties. Running a simulation with those models then reveals the molecule’s spectral fingerprint.
But physical factors can subtly influence the wavelengths that molecules emit. Such was the case with Cassiopeia A. Although the spectroscopy data of Cassiopeia A showed wavelengths close to what would be expected from silica, researchers could not match the data with any particular element or molecule.
Jeonghee Rho, an astronomer at the SETI Institute in Mountain View, California, and the lead author on the new paper, thought that perhaps the shape of the silica grains could be the source of the discrepancy, because existing silica models assumed the grains were perfectly spherical.
She began building models that included some grains with nonspherical shapes. It was only when she completed a model that assumed all the grains were not spherical but, rather, football-shaped that the model “really clearly produced the same spectral feature we see in the Spitzer data,” Rho said.
Rho and her coauthors on the paper then found the same feature in a second supernova remnant, G54.1+0.3. The elongated grains may tell scientists something about the exact processes that formed the silica.
The authors also combined the observations of the two supernova remnants from Spitzer with observations from the European Space Agency’s Herschel Space Observatory in order to measure the amount of silica produced by each explosion. Herschel detects different wavelengths of infrared light than Spitzer. The researchers looked at the entire span of wavelengths provided by both observatories and identified the wavelength at which the dust has its peak brightness. That information can be used to measure the temperature of dust, and both brightness and temperature are necessary in order to measure the mass. The new work implies that the silica produced by supernovas over time was significant enough to contribute to dust throughout the universe, including the dust that ultimately came together to form our home planet.
The study was published on Oct. 24, 2018, in the Monthly Notices of the Royal Astronomical Society, and it confirms that every time we gaze through a window, walk down the sidewalk or set foot on a pebbly beach, we are interacting with a material made by exploding stars that burned billions of years ago.
NASA’s Herschel Project Office is based at NASA’s Jet Propulsion Laboratory in Pasadena, California. The NASA Herschel Science Center, part of IPAC, supports the U.S. astronomical community. Caltech manages JPL for NASA.
The JPL manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena, California. Spacecraft operations are based at Lockheed Martin Space in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech.

For more information about Herschel and Spitzer, visit:

http://www.herschel.caltech.edu  http://www.spitzer.caltech.edu  https://www.nasa.gov/spitzer

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Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.

Rebecca McDonald
Director of Communications, SETI Institute

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NASA, Northrop Grumman Launch Space Station, National Lab Cargo

Northrop Grumman – NG-10 CRS Cygnus patch.

Nov. 17, 2018

Image above: Northrop Grumman’s Cygnus spacecraft launches on an Antares rocket at 4:01 a.m. EST Nov. 17, 2018, from the Virginia Mid-Atlantic Regional Spaceport’s Pad-0A at NASA’s Wallops Flight Facility in Virginia. Northrop Grumman’s 10th contracted cargo resupply mission for NASA to the International Space Station will deliver about 7,400 pounds of science and research, crew supplies and vehicle hardware to the orbital laboratory and its crew. Image Credits: NASA/Joel Kowsky.

Northrop Grumman’s Cygnus spacecraft is on its way to the International Space Station with about 7,400 pounds of cargo after launching at 4:01 a.m. EST Saturday from NASA’s Wallops Flight Facility on Virginia’s Eastern Shore.

Image above: Northrop Grumman’s Cygnus cargo spacecraft blasted off at 4:01 a.m. EST today loaded with about 7,400 pounds of science, supplies and goodies for the station crew. Image Credits: NASA/Joel Kowsky.

The spacecraft launched on an Antares 230 Rocket from the Virginia Mid-Atlantic Regional Spaceport’s Pad 0A at Wallops on the company’s 10th cargo delivery flight, and is scheduled to arrive at the orbital laboratory Monday, Nov. 19. Expedition 57 astronauts Serena Auñón-Chancellor of NASA and Alexander Gerst of ESA (European Space Agency) will use the space station’s robotic arm to grapple Cygnus about 5:20 a.m. Installation coverage will begin at 4 a.m. on NASA Television and the agency’s website.

NG CRS-10: Antares 230 launches SS John Young Cygnus spacecraft

This Commercial Resupply Services contract mission will support dozens of new and existing investigations as Expeditions 57 and 58 contribute to some 250 science and research studies. Highlights from the new experiments include a demonstration of 3D printing and recycling technology and simulating the creation of celestial bodies from stardust.

Recycling and Fabrication in Space

The Refabricator is the first-ever 3D printer and recycler integrated into one user-friendly machine. Once it’s installed in the space station, it will demonstrate recycling of waste plastic and previously 3D printed parts already on-board into high-quality filament (i.e. 3D printer ‘ink’). This recycled filament will then be fed into the printer to make new tools and parts on-demand in space. This technology could enable closed-loop, sustainable fabrication, repair and recycling on long-duration space missions, and greatly reduce the need to continually launch large supplies of new material and parts for repairs and maintenance.

The demonstration, which NASA’s Space Technology Mission and Human Exploration and Operations Directorates co-sponsored, is considered a key enabling technology for in-space manufacturing. NASA awarded a Small Business Innovation Research contract valued to Tethers Unlimited Inc. to build the recycling system.

Cygnus 5 approaching the ISS. Image Credit: NASA/ISS-45

Formation of the Early Solar System

The Experimental Chondrule Formation at the International Space Station (EXCISS) investigation will explore how planets, moons and other objects in space formed by simulating the high-energy, low-gravity conditions that were present during formation of the early solar system. Scientists plan to zap a specially formulated dust with an electrical current, and then study the shape and texture of the resulting pellets.

Understanding Parkinson’s Disease

The Crystallization of LRRK2 Under Microgravity Conditions-2 (PCG-16) investigation grows large crystals of an important protein, leucine-rich repeat kinase 2 (LRRK2), in microgravity for analysis back on Earth. This protein is implicated in development of Parkinson’s disease, and improving our knowledge of its structure may help scientists better understand the pathology of the disease and develop therapies to treat it. LRRK2 crystals grown in gravity are too small and too compact to study, making microgravity an essential part of this research. This investigation is sponsored by the U.S. National Laboratory on the space station, which Congress designated in 2005 to maximize its use for improving quality of life on Earth.

Northrop Grumman CRS-10 Mission to the Space Station: What’s On Board?

The Cygnus spacecraft will remain at the space station until February before its destructive reentry into Earth’s atmosphere, disposing of several thousand pounds of trash. This is the seventh flight of an enhanced Cygnus spacecraft, and the fourth using Northrop Grumman’s upgraded Antares 230 launch vehicle featuring new RD-181 engines that provide increased performance and flexibility.

The spacecraft for this mission is named in honor of astronaut John Young. Young was selected for NASA’s second astronaut class and flew during the Gemini, Apollo and Space Shuttle programs. He walked on the Moon during Apollo 16 in 1972 and commanded the first space shuttle mission in 1981. Young passed away in January.

Learn more about Northrop Grumman’s mission at: https://www.nasa.gov/northropgrumman

For more than 18 years, humans have lived and worked continuously aboard the International Space Station, advancing scientific knowledge and demonstrating new technologies, making research breakthroughs not possible on Earth that will enable long-duration human and robotic exploration into deep space. A global endeavor, 230 people from 18 countries have visited the unique microgravity laboratory that has hosted more than 2,500 research investigations from researchers in 106 countries.

Keep up with the International Space Station, and its research and crews, at: https://www.nasa.gov/station

Commercial Resupply: http://www.nasa.gov/mission_pages/station/structure/launch/index.html

NASA TV: http://www.nasa.gov/live

Images (mentioned), Videos, Text, Credits: NASA/Josh Finch/Karen Northon/JSC/Gary Jordan/NASA TV/SciNews.

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