Armed with state-of-the-art supercomputer models, scientists have shown that colliding neutron stars can produce the energetic jet required for a gamma-ray burst. Earlier simulations demonstrated that mergers could make black holes. Others had shown that the high-speed particle jets needed to make a gamma-ray burst would continue if placed in the swirling wreckage of a recent merger. Now, the simulations reveal the middle step of the process—how the merging stars' magnetic field organizes itself into outwardly directed components capable of forming a jet. The Damiana supercomputer at Germany's Max Planck Institute for Gravitational Physics needed six weeks to reveal the details of a process that unfolds in just 35 thousandths of a second—less than the blink of an eye.For the researchers' website, with more video and stills of their simulations, go here. ||

This video introduces a new computer simulation exploring the connection between two of the most elusive phenomena in the universe, black holes and dark matter. In the visualization, dark matter particles are gray spheres attached to shaded trails representing their motion. Redder trails indicate particles more strongly affected by the black hole's gravitation and closer to its event horizon (black sphere at center, mostly hidden by trails). The ergosphere, where all matter and light must follow the black hole's spin, is shown in teal. Watch this video on the NASA Goddard YouTube channel.Credit: NASA's Goddard Space Flight CenterFor complete transcript, click here. || DMBH_Still.jpg (1920x1080) [555.7 KB] || 11894_Dark_Matter_Black_Hole_H264_Good_1920x1080_2997.webm (1920x1080) [25.0 MB] || 11894_Dark_Matter_Black_Hole_ProRes_1920x1080_2997.mov (1920x1080) [3.1 GB] || 11894_Dark_Matter_Black_Hole_MPEG4_1920X1080_2997.mp4 (1920x1080) [135.4 MB] || 11894_Dark_Matter_Black_Hole_H264_Best_1920x1080_2997.mov (1920x1080) [2.1 GB] || 11894_Dark_Matter_Black_Hole_H264_Good_1920x1080_2997.mov (1920x1080) [356.2 MB] || G2015-040_Dark_Matter_Black_Hole_appletv.m4v (960x540) [93.0 MB] || G2015-040_Dark_Matter_Black_Hole_1280x720.wmv (1280x720) [103.5 MB] || G2015-040_Dark_Matter_Black_Hole_appletv_subtitles.m4v (960x540) [92.9 MB] || G2015-040_Dark_Matter_Black_Hole_ipod_lg.m4v (640x360) [37.6 MB] || 11894_Dark_Matter_Black_Hole_SRT_Captions.en_us.en_US.srt [4.2 KB] || 11894_Dark_Matter_Black_Hole_SRT_Captions.en_us.en_US.vtt [4.2 KB] || G2015-040_Dark_Matter_Black_Hole_ipod_sm.mp4 (320x240) [20.1 MB] ||

A wave spanning 200,000 light-years is rolling through the Perseus galaxy cluster, according to observations from NASA's Chandra X-ray Observatory coupled with a computer simulation. The simulation shows the gravitational disturbance resulting from the distant flyby of a galaxy cluster about a tenth the mass of the Perseus cluster. The event causes cooler gas at the heart of the Perseus cluster to form a vast expanding spiral, which ultimately forms giant waves lasting hundreds of millions of years at its periphery. Merger events like this are thought to occur as often as every three to four billion years in clusters like Perseus.Credit: NASA's Goddard Space Flight CenterMusic: "The Undiscovered" from Killer TracksWatch this video on the NASA Goddard YouTube channel.Complete transcript available. || Perseus_Simulation_Final_Frame_print.jpg (1024x575) [47.6 KB] || Perseus_Simulation_Final_Frame.png (7342x4129) [4.0 MB] || Perseus_Simulation_Final_Frame_thm.png (80x40) [3.3 KB] || Perseus_Simulation_Final_Frame_searchweb.png (320x180) [39.3 KB] || 12587_Perseus_Wind_FINAL_VX-281959_appletv_subtitles.m4v (1280x720) [85.7 MB] || 12587_Perseus_Wind_1080.webm (1920x1080) [18.2 MB] || 12587_Perseus_Wind_FINAL_VX-281959_appletv.m4v (1280x720) [85.6 MB] || 12587_Perseus_Wind_1080.m4v (1920x1080) [160.3 MB] || 12587_Perseus_Wind_1080.mov (1920x1080) [241.7 MB] || 12587_Perseus_Wind_SRT_Caption.en_US.vtt [1.7 KB] || 12587_Perseus_Wind_SRT_Caption.en_US.srt [1.7 KB] || WMV_12587_Perseus_Wind_FINAL_VX-281959_HD.wmv (3840x2160) [154.8 MB] || 12587_Perseus_Wind.mp4 (3840x2160) [306.3 MB] || 12587_Perseus_Wind_Good_4k.mov (3840x2160) [468.4 MB] || 12587_Perseus_Wind_4K.m4v (3840x2160) [792.0 MB] || 12587_Perseus_Wind_FINAL_VX-281959_youtube_hq.mov (3840x2160) [1.2 GB] || 12587_Perseus_Wind_ProRes_3840x2160_2997.mov (3840x2160) [5.2 GB] ||

Gas glows brightly in this computer simulation of supermassive black holes only 40 orbits from merging. Models like this may eventually help scientists pinpoint real examples of these powerful binary systems. Credit: NASA's Goddard Space Flight Center/Scott Noble; simulation data, d'Ascoli et al. 2018Music: "Games Show Sphere 01" from Killer TracksWatch this video on the NASA Goddard YouTube channel.Complete transcript available. || SMBH_Sim_Still_1.jpg (1920x1080) [333.8 KB] || SMBH_Sim_Still_1_print.jpg (1024x576) [138.8 KB] || SMBH_Sim_Still_1_searchweb.png (320x180) [69.3 KB] || SMBH_Sim_Still_1_thm.png (80x40) [6.4 KB] || 13043_SMBH_Simulation_1080.webm (1920x1080) [17.4 MB] || 13043_SMBH_Simulation_1080.mp4 (1920x1080) [202.8 MB] || SMBH_SRT_Captions.en_US.srt [2.0 KB] || SMBH_SRT_Captions.en_US.vtt [1.9 KB] || 13043_SMBH_Simulation_ProRes_1920x1080_2997.mov (1920x1080) [2.0 GB] ||

Every three hours, NASA's Fermi Gamma-ray Space Telescope scans the entire sky and deepens its portrait of the high-energy universe. Every year, the satellite's scientists reanalyze all of the data it has collected, exploiting updated analysis methods to tease out new sources. These relatively steady sources are in addition to the numerous transient events Fermi detects, such as gamma-ray bursts in the distant universe and flares from the sun.Earlier this year, the Fermi team released its second catalog of sources detected by the satellite's Large Area Telescope (LAT), producing an inventory of 1,873 objects shining with the highest-energy form of light. More than half of these sources are active galaxies whose supermassive black hole centers are causing the gamma-ray emissions. ||

A comprehensive study of hundreds of galaxies observed by the Keck telescopes in Hawaii and NASA's Hubble Space Telescope has revealed an unexpected pattern of change that extends back 8 billion years, or more than half the age of the universe."Astronomers thought disk galaxies in the nearby universe had settled into their present form by about 8 billion years ago, with little additional development since," said Susan Kassin, an astronomer at NASA's Goddard Space Flight Center in Greenbelt, Md., and the study's lead researcher. "The trend we've observed instead shows the opposite, that galaxies were steadily changing over this time period."Today, star-forming galaxies take the form of orderly disk-shaped systems, such as the Andromeda Galaxy or the Milky Way, where rotation dominates over other internal motions. The most distant blue galaxies in the study tend to be very different, exhibiting disorganized motions in multiple directions. There is a steady shift toward greater organization to the present time as the disorganized motions dissipate and rotation speeds increase. These galaxies are gradually settling into well-behaved disks.Blue galaxies — their color indicates stars are forming within them — show less disorganized motions and ever-faster rotation speeds the closer they are observed to the present. This trend holds true for galaxies of all masses, but the most massive systems always show the highest level of organization.Researchers say the distant blue galaxies they studied are gradually transforming into rotating disk galaxies like our own Milky Way.Watch this video on YouTube. ||

A new study by astronomers at NASA, Johns Hopkins University and the Rochester Institute of Technology confirms long-held suspicions about how stellar-mass black holes produce their highest-energy light. By analyzing a supercomputer simulation of gas flowing into a black hole, the team finds they can reproduce a range of important X-ray features long observed in active black holes. Jeremy Schnittman, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md., led the research.Black holes are the densest objects known. Stellar black holes form when massive stars run out of fuel and collapse, crushing up to 20 times the sun's mass into compact objects less than 75 miles (120 kilometers) wide. Gas falling toward a black hole initially orbits around it and then accumulates into a flattened disk. The gas stored in this disk gradually spirals inward and becomes greatly compressed and heated as it nears the center, ultimately reaching temperatures up to 20 million degrees Fahrenheit (12 million C), or some 2,000 times hotter than the sun's surface. It glows brightly in low-energy, or soft, X-rays.For more than 40 years, however, observations show that black holes also produce considerable amounts of "hard" X-rays, light with energy tens to hundreds of times greater than soft X-rays. This higher-energy light implies the presence of correspondingly hotter gas, with temperatures reaching billions of degrees. The new study involves a detailed computer simulation that simultaneously tracked the fluid, electrical and magnetic properties of the gas while also taking into account Einstein's theory of relativity. Using this data, the scientists developed tools to track how X-rays were emitted, absorbed, and scattered in and around the disk. The study demonstrates for the first time a direct connection between magnetic turbulence in the disk, the formation of a billion-degree corona above and below the disk, and the production of hard X-rays around an actively "feeding" black hole.Watch this video on YouTube. ||

This supercomputer simulation shows one of the most violent events in the universe: a pair of neutron stars colliding, merging and forming a black hole. A neutron star is the compressed core left behind when a star born with between eight and 30 times the sun's mass explodes as a supernova. Neutron stars pack about 1.5 times the mass of the sun — equivalent to about half a million Earths — into a ball just 12 miles (20 km) across. As the simulation begins, we view an unequally matched pair of neutron stars weighing 1.4 and 1.7 solar masses. They are separated by only about 11 miles, slightly less distance than their own diameters. Redder colors show regions of progressively lower density. As the stars spiral toward each other, intense tides begin to deform them, possibly cracking their crusts. Neutron stars possess incredible density, but their surfaces are comparatively thin, with densities about a million times greater than gold. Their interiors crush matter to a much greater degree densities rise by 100 million times in their centers. To begin to imagine such mind-boggling densities, consider that a cubic centimeter of neutron star matter outweighs Mount Everest. By 7 milliseconds, tidal forces overwhelm and shatter the lesser star. Its superdense contents erupt into the system and curl a spiral arm of incredibly hot material. At 13 milliseconds, the more massive star has accumulated too much mass to support it against gravity and collapses, and a new black hole is born. The black hole's event horizon — its point of no return — is shown by the gray sphere. While most of the matter from both neutron stars will fall into the black hole, some of the less dense, faster moving matter manages to orbit around it, quickly forming a large and rapidly rotating torus. This torus extends for about 124 miles (200 km) and contains the equivalent of 1/5th the mass of our sun. The entire simulation covers only 20 milliseconds.Scientists think neutron star mergers like this produce short gamma-ray bursts (GRBs). Short GRBs last less than two seconds yet unleash as much energy as all the stars in our galaxy produce over one year. The rapidly fading afterglow of these explosions presents a challenge to astronomers. A key element in understanding GRBs is getting instruments on large ground-based telescopes to capture afterglows as soon as possible after the burst. The rapid notification and accurate positions provided by NASA's Swift mission creates a vibrant synergy with ground-based observatories that has led to dramatically improved understanding of GRBs, especially for short bursts. ||

Explore Eta Carinae from the inside out with the help of supercomputer simulations and data from NASA satellites and ground-based observatories. Credit: NASA's Goddard Space Flight CenterWatch this video on the NASA Goddard YouTube channel.For complete transcript, click here. || Eta_Car_Density_XY_R10_R100_STILL_1920.jpg (1920x1080) [804.4 KB] || Eta_Car_Density_XY_R10_R100_STILL_1920_print.jpg (1024x576) [52.0 KB] || Eta_Car_Density_XY_R10_R100_STILL.jpg (4928x2772) [874.1 KB] || Eta_Car_Density_XY_R10_R100_STILL.png (4928x2772) [36.6 MB] || Eta_Car_Density_XY_R10_R100_STILL_1920_web.jpg (320x180) [13.1 KB] || Eta_Car_Density_XY_R10_R100_STILL_1920_searchweb.png (320x180) [55.9 KB] || Eta_Car_Density_XY_R10_R100_STILL_1920_thm.png (80x40) [8.0 KB] || Eta_Car_Density_XY_R10_R100_STILL_1920.tiff (1920x1080) [11.9 MB] || G2015-001_Eta_Car_Binary_Final_appletv.webm (960x540) [30.5 MB] || G2015-001_Eta_Car_Binary_Final_ipod_lg.m4v (640x360) [43.2 MB] || G2015-001_Eta_Car_Binary.en_US.vtt [5.2 KB] || G2015-001_Eta_Car_Binary.en_US.srt [5.2 KB] || G2015-001_Eta_Car_Binary_Final_ipod_sm.mp4 (320x240) [22.8 MB] || G2015-001_Eta_Car_Binary_Final_appletv_subtitles.m4v (960x540) [103.9 MB] || G2015-001_Eta_Car_Binary_Final_appletv.m4v (960x540) [104.0 MB] || G2015-001_Eta_Car_Binary_Final_1280x720.wmv (1280x720) [107.6 MB] || 11725_Eta_Car_Binary2_MPEG4_1920X1080_2997.mp4 (1920x1080) [116.9 MB] || 11725_Eta_Car_Binary2_ProRes_1920x1080_2997.mov (1920x1080) [3.5 GB] || 11725_Eta_Car_Binary2_H264_Best_1920x1080_2997.mov (1920x1080) [2.6 GB] || 11725_Eta_Car_Binary2_H264_Good_1920x1080_2997.mov (1920x1080) [506.2 MB] || Eta_Car_Density_XY_R10_R100_STILL.tiff (4928x2772) [104.2 MB] ||

This visualization shows gamma rays detected during 3C 279's big flare by the LAT instrument on NASA's Fermi satellite. The flare is an abrupt shower of "rain" that trails off toward the end of the movie. Gamma rays are represented as expanding circles reminiscent of raindrops on water. Both the maximum size of the circle and its color represent the energy of the gamma ray, with white lowest and magenta highest. The highest-energy gamma ray the LAT detected during this flare, 52 billion electron volts, arrives near the end. In a second version of the visualization, a background map shows how the LAT detects 3C 279 and other sources by accumulating high-energy photons over time (brighter squares reflect higher numbers of gamma rays). The movie starts on June 14 and ends June 17. The area shown is a region of the sky five degrees on a side and centered on the position of 3C 279.  Credit: NASA/DOE/Fermi LAT CollaborationWatch this video on the NASA Goddard YouTube channel.For complete transcript, click here. || Fermi_Rain_Still2.jpg (1920x1080) [144.1 KB] || Fermi_Rain_Still2_print.jpg (1024x576) [51.2 KB] || Fermi_Rain_Still2_searchweb.png (320x180) [24.0 KB] || Fermi_Rain_Still2_thm.png (80x40) [5.0 KB] || Fermi_GammaRay_Rain_Final_1080.m4v (1920x1080) [81.8 MB] || WMV_Fermi_GammaRay_Rain_Final_1280x720.wmv (1280x720) [24.3 MB] || APPLE_TV_Fermi_GammaRay_Rain_Final_appletv.m4v (1280x720) [39.3 MB] || YOUTUBE_HQ_Fermi_GammaRay_Rain_Final_youtube_hq.webm (1280x720) [8.5 MB] || APPLE_TV_Fermi_GammaRay_Rain_Final_appletv_subtitles.m4v (1280x720) [39.3 MB] || Fermi_GammaRay_Rain_1080p.mov (1920x1080) [110.6 MB] || Fermi_GammaRay_Rain_Final_ProRes_1920x1080_2997.mov (1920x1080) [530.3 MB] || Fermi_GammaRay_Rain_SRT_Captions.en_US.srt [415 bytes] || Fermi_GammaRay_Rain_SRT_Captions.en_US.vtt [428 bytes] ||