Rear-end Collisions Between High-speed Knots in Relativistic Jet

Produces shocks that accelerate particles, illuminating the colliding material 

The Hubble Space Telescope took this image of the core region of galaxy NGC 3862 with relativistic jet of material visible as line of light in the 3 o'clock position. Images to the right show knots of material outlined in blue, red and green moving along the jet over two decades. X marks the supermassive black hole. Credits: NASA/ESA/Hubble
The Hubble Space Telescope took this image of the core region of galaxy NGC 3862 with relativistic jet of material visible as line of light in the 3 o’clock position. Images to the right show knots of material outlined in blue, red and green moving along the jet over two decades. X marks the supermassive black hole.
Credits: NASA/ESA/Hubble

Space news (astrophysics: relativistic jets; shock collisions inside particle jets) – Observing plasma jet blasting from supermassive black hole in core of galaxy NGC 3862, 260 million light-years from Earth toward the constellation Leo in the rich galaxy cluster Abell 1367 –

Astronomers recently made an interesting discovery while studying data collected by the Hubble Space Telescope over two decades of observing the core of elliptical galaxy NGC 3862.  They were originally looking to create a time-lapse video of a relativistic jet blasting from the supermassive black hole thought to reside within its core. Instead, they discovered a rear-end collision between two separate high-speed waves of material ejected by a monster black hole whose mass astronomers have yet to measure. In this case, scientists believe the rear-end collision accelerated and heated particles which illuminated the colliding material for Hubble to see.

The relativistic jet erupting from the accretion disk of the supermassive black hole thought to reside at the core of galaxy NGC 3862 is one of the most studied and therefore best understood. It’s also one of the few active galaxies with jets observed in visible light. It appears to stream out of the accretion disk at speeds several times the speed of light, but this is just a visual illusion referred to as superluminal motion created by the combination of insanely fast velocities and our line of sight being almost on point. It forms a narrow beam hundreds of light-years in length that eventually begins to spread out like a cone, before forming clumps at around 1,000 light-years. Clumps scientists study looking for clues pointing to facts they can use to learn more about these plasma jets and the cosmos.

Astronomers have observed knots of material being ejected from dense stellar objects previously during the human journey to the beginning of space and time. This is one of the few times they have detected knots with an optical telescope thousands of light-years from a supermassive black hole. It’s the certainly the first time we have detected a rear-end collision between separately ejected knots in a relativistic jet. 

“Something like this has never been seen before in an extragalactic jet,” said Eileen Meyer of NASA’s Space Telescope Science Institute (STScI). “As the knots continue merging they will brighten further in the coming decades. This will allow us a very rare opportunity to see how the energy of the collision is dissipated into radiation.”

What would cause successive jets of material to achieve varying speeds? One theory involves the idea of material falling onto the supermassive black hole being superheated and ejected along its spin axis. Ejected material is constrained by the powerful magnetic fields surrounding the monster black hole into a narrow beam. If the flow of falling material isn’t perfectly smooth, knots are ejected in a string, rather than a continuous beam or steady hose.

It’s possible knots ejected later travel through a less dense interstellar medium, which would result in varying speeds. In this scenario, a knot launched after another knot would eventually catch up and rear-end it. 

Beyond learning knots of material ejected in plasma jets erupting from the accretion disk of a supermassive black hole sometimes rear-end each other, astronomers are interested in this second case of superluminal motion observed in jets hundreds, thousands of light-years from the source supermassive black hole. This indicates the jets are still moving at nearly the speed of light at distances rivaling the scale of the host galaxy and still contain tremendous energy. Understanding this could help astronomers determine more about the evolution of galaxies as the cosmos ages, including our own Milky Way.

Astronomers are also trying to figure out why galaxy NGC 3862 is one of the few they have detected jets in optical wavelengths? They haven’t been able to come up with any good theories on why some jets are detected in visible light and others aren’t. 

Work goes on

Work at the institute continues. Meyer is currently working on additional videos using Hubble images of other relativistic jets in nearby galaxies to try to detect superluminal motion. This is only possible due to the longevity of the Hubble Space Telescope and ingenuity of engineers and scientists from NASA and the ESA. Hopefully, they could discover more clues to answer these questions and other mysteries gnawing at the corner of my mind.

Watch this video made by Eileen Meyer of the Space Telescope Science Institute (STScI) in Baltimore, Maryland using archival data from two decades of Hubble Space Telescope observations of galaxy NGC 3862.

Read about magnetic lines of force NASA astronomers viewed emanating from a supermassive black hole 900 million light-years from Earth.

Read and learn more about how astronomers study the formation of stars in the Milky Way.

Read about a runaway star discovered traveling across the Tarantula Nebula.

Take the space voyage of NASA.

Read and learn more about relativistic jets here.

Learn more about the discoveries made by the ESA.

Learn more about galaxy NGC 3862 here.

Learn what astronomers have discovered about supermassive black holes.

Discover and learn more about superluminal motion here.

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China’s Long March to the Stars Continues

Long March 7 rocket launches on maiden voyage from China’s new Wenchang Space Launch Center 

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Space news (Chinese space program: new launch systems; Long March 7 (LM-7) rocket) – 12:00 UTC, Wenchang Space Launch Center, Hainan Island, China – 

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China’s next-generation medium-lift orbital launch vehicle the Chang Zheng-7 (CZ-7) lifted slowly from Launch Complex LC101 of China’s new Wenchang Space Launch Center at 12:00 UTC (5:00 PST) on June 25, 2016. On the maiden voyage of China’s new Long March 7 (LM-7) rocket to test its flight capabilities in anticipation of achieving operational status and eventually qualifying for unmanned and manned space missions in the future.

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Carrying a smaller, scaled-down prototype of their next generation crew capsule (NGCV) that was successfully recovered later in Inner Mongolia, the LM-7 test flight went off without a hitch. China’s new launch vehicle was developed by China Academy of Launch Vehicle Technology (CALT) to replace the aging LM-2, LM-3, and LM-4 hypergolic launch vehicles in the future. It will also be used to lift their new Tianzhou cargo vehicle into orbit for the Tiangong-2 program, along with modules for the Tiangong space station in a few years. 

The new LM-7 is powered by the YF-100, a two-stage combustion cycle engine developed at China’s Academy of Aerospace Liquid Propulsion Technology, and certified for use by the State Administration of Science, Technology, and Industry for National Defence. The first stage uses two engines and strap-on boosters each with a single engine. The second stage utilizes a YF-115 with four engines. China’s new medium-lift orbital launch vehicle operates on liquid oxygen and kerosene, capable of a lift-off thrust of 7,200 kN, and carrying around 13,500 kg 400 km, or 5,500 kg 700 km, above the surface of the Earth.

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Located in the northeast corner of the island of Hainan on the southern coast of China, a place on the Earth closer to the equator than their three other launch complexes, vehicles launched from China’s new Wenchang Space Launch Center benefit from the increased rotational speed of the planet at this location as compared to the other three sites. It reduces the amount of fuel required for the launch vehicle to maneuver from transit orbit to GEO. It should also avoid the possibility of rocket debris falling into populated areas since the launch vehicle can be directed toward the southeast and into the expansive South Pacific. 

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China’s next generation crew vehicle (NGCV) the Shenzhou manned space capsule’s based on the proven Russian Soyuz design. China expects to implement their new crew vehicle during the launch and construction of the Tiangong-2 space station near the end of 2016. They’ll also use it during the orbital construction of the modular Tiangong space station currently scheduled for the beginning of 2018. China’s in the development of new next generation manned space capsules to enable future and more ambitious space missions to the Moon and even manned missions to the Red Planet. 

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China’s heading to the stars

They expect to use their future space capsules to ferry material and astronauts to and from space stations in the LEO, to send explorers to the Moon, near-Earth asteroids, and possibly Mars once they’re ready. Capable of carrying 2 to 6 astronauts, it will have two versions, a 14-ton version for traveling to LEO, near-Earth asteroids, and Mars, and a 20-ton model for lunar missions. Designed and engineered to spend up to 21 days in independent orbit or two years if docked at a space station, China’s next generation space capsule (NGCV)’s a versatile beast fitted with two different service modules, each with a different propulsion system. A beast expected to take China’s astronauts and dreams of exploring the solar system to Mars and beyond during the decades ahead for their space program.  

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Read and learn about NASA’s selection of five American aerospace firms to study concepts for missions to Mars.

Read about Astro-D, Advanced Satellite for Cosmology and Astrophysics.

Learn about the incredible star navigation skills of the Polynesian islanders that colonized the islands of the Pacific Ocean.

Join the space journey of China as it makes plans to explore the solar system and beyond here

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Explore the launch vehicles designed and built by China Academy of Launch Vehicle Technology.

Learn more about China’s Academy of Aerospace Liquid Propulsion Technology here

Feedback Mechanisms of Actively Feeding Supermassive Black Holes

Can blow star-forming gas 1000 light-years out of core region of host galaxies 

This artist's rendering shows a galaxy being cleared of interstellar gas, the building blocks of new stars. New X-ray observations by Suzaku have identified a wind emanating from the black hole's accretion disk (inset) that ultimately drives such outflows. Credits: ESA/ATG Medialab
This artist’s rendering shows a galaxy being cleared of interstellar gas, the building blocks of new stars. New X-ray observations by Suzaku have identified a wind emanating from the black hole’s accretion disk (inset) that ultimately drives such outflows.
Credits: ESA/ATG Medialab

Space news (astrophysics: evolution of galaxies; feedback mechanisms) – about 2.3 billion years ago in a galaxy far, far away and standing in a fierce, 2 million mile per hour (3 million kilometers per hour) outflow of star-forming gas – 

Astrophysicists studying the evolution of galaxies using the Suzaku X-ray satellite and the European Space Agency’s Herschel Infrared Space Observatory have found evidence suggesting supermassive black holes significantly influence the evolution of their host galaxies. They found data pointing to winds near a monster black hole blowing star-forming gas over 1,000 light-years from the galaxy center. Enough material to form around 800 stars with the mass of our own Sol. 

“This is the first study directly connecting a galaxy’s actively ‘feeding’ black hole to features found at much larger physical scales,” said lead researcher Francesco Tombesi, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, College Park (UMCP). “We detect the wind arising from the luminous disk of gas very close to the black hole, and we show that it’s responsible for blowing star-forming gas out of the galaxy’s central regions.” 

The artist’s view of galaxy IRAS F11119+3257 (F11119) above shows 3 million miles per hour winds produced near the supermassive black hole at its center heating and dispersing cold, dense molecular clouds that could form new stars. Astronomers believe these winds are part of a feedback mechanism that blows star-forming gas from galaxy centers, forever altering the structure and evolution of their host galaxy.  

A red-filter image of IRAS F11119+3257 (inset) from the University of Hawaii's 2.2-meter telescope shows faint features that may be tidal debris, a sign of a galaxy merger. Background: A wider view of the region from the Sloan Digital Sky Survey. Credits: NASA's Goddard Space Flight Center/SDSS/S. Veilleux
A red-filter image of IRAS F11119+3257 (inset) from the University of Hawaii’s 2.2-meter telescope shows faint features that may be tidal debris, a sign of a galaxy merger. Background: A wider view of the region from the Sloan Digital Sky Survey.
Credits: NASA’s Goddard Space Flight Center/SDSS/S. Veilleux

Astronomers have been studying the Monster of the Milky Way, the supermassive black hole with an estimated mass six million times that of Sol thought to reside at the center of our galaxy, for years. The monster black hole at the core of F11119 is thought to contain around 16 million times the mass of Sol. The accretion disk surrounding this supermassive black hole is measured at hundreds of times the diameter of our solar system. The 170 million miles per hour (270 million kilometers per hour) winds emanating from its accretion disk push the star-forming dust out of the central regions of the galaxy. Producing a steady flow of cold gas over a thousand light-years across traveling at around 2 million mph (3 million kph) and moving a volume of mass equal to around 800 Suns. 

Astrophysicists have been searching for clues to a possible correlation between the masses of a galaxy’s central supermassive black hole and its galactic bulge. They have observed galaxies with more massive black holes generally, have bulges with proportionately larger stellar mass. The steady flow of material out of the central regions of galaxy F11119 and into the galactic bulge could help explain this correlation. 

“These connections suggested the black hole was providing some form of feedback that modulated star formation in the wider galaxy, but it was difficult to see how,” said team member Sylvain Veilleux, an astronomy professor at UMCP. “With the discovery of powerful molecular outflows of cold gas in galaxies with active black holes, we began to uncover the connection.” 

“The black hole is ingesting gas as fast as it can and is tremendously heating the accretion disk, allowing it to produce about 80 percent of the energy this galaxy emits,” said co-author Marcio Meléndez, a research associate at UMCP. “But the disk is so luminous some of the gas accelerates away from it, creating the X-ray wind we observe.” 

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In this artist’s rendering, a thick accretion disk has formed around a supermassive black hole following the tidal disruption of a star that wandered too close. Stellar debris has fallen toward the black hole and collected into a thick chaotic disk of hot gas. Flashes of X-ray light near the center of the disk result in light echoes that allow astronomers to map the structure of the funnel-like flow, revealing for the first time strong gravity effects around a normally quiescent black hole. Credits: NASA/Swift/Aurore Simonnet, Sonoma State University

The accretion disk wind and associated molecular outflow of cold gas could be the final pieces astronomers have been looking for in the puzzle explaining supermassive black hole feedback. Watch this video animation of the workings of supermassive black hole feedback in quasars

Black-hole-powered galaxies called blazars are the most common sources detected by NASA's Fermi Gamma-ray Space Telescope. As matter falls toward the supermassive black hole at the galaxy's center, some of it is accelerated outward at nearly the speed of light along jets pointed in opposite directions. When one of the jets happens to be aimed in the direction of Earth, as illustrated here, the galaxy appears especially bright and is classified as a blazar. Credits: M. Weiss/CfA
Black-hole-powered galaxies called blazars are the most common sources detected by NASA’s Fermi Gamma-ray Space Telescope. As matter falls toward the supermassive black hole at the galaxy’s center, some of it is accelerated outward at nearly the speed of light along jets pointed in opposite directions. When one of the jets happens to be aimed in the direction of Earth, as illustrated here, the galaxy appears especially bright and is classified as a blazar.
Credits: M. Weiss/CfA

When the supermassive black hole’s most active, it clears cold gas and dust from the center of the galaxy and shuts down star formation in this region. It also allows shorter-wavelength light to escape from the accretion disk of the black hole astronomers can study to learn more. We’ll keep you updated on any additional discoveries. 

What’s the conclusion?

Astrophysicists conclude F11119 could be an early evolutionary phase of a quasar, a type of active galactic nuclei (AGN) with extreme emissions across a broad spectrum. Computer simulations show the supermassive black hole should eventually consume the gas and dust in its accretion disk and then its activity should lessen. Leaving a less active galaxy with little gas and a comparatively low level of star formation. 

Blazar 3C 279's historic gamma-ray flare can be seen in these images from the Large Area Telescope (LAT) on NASA's Fermi satellite. Both images show gamma rays with energies from 100 million to 100 billion electron volts (eV). For comparison, visible light has energies between 2 and 3 eV. Left: A week-long exposure ending June 10, before the eruption. Right: An exposure for the following week, including the flare. 3C 279 is brighter than the Vela pulsar, normally the brightest object in the gamma-ray sky. The scale bar at left shows an angular distance of 10 degrees, which is about the width of a clenched fist at arm's length. Credits: NASA/DOE/Fermi LAT Collaboration
Blazar 3C 279’s historic gamma-ray flare can be seen in these images from the Large Area Telescope (LAT) on NASA’s Fermi satellite. Both images show gamma rays with energies from 100 million to 100 billion electron volts (eV). For comparison, visible light has energies between 2 and 3 eV. Left: A week-long exposure ending June 10, before the eruption. Right: An exposure for the following week, including the flare. 3C 279 is brighter than the Vela pulsar, normally the brightest object in the gamma-ray sky. The scale bar at left shows an angular distance of 10 degrees, which is about the width of a clenched fist at arm’s length.
Credits: NASA/DOE/Fermi LAT Collaboration

Astrophysicists and scientists look forward to detecting and studying feedback mechanisms connected with the growth and evolution of supermassive black holes using the enhanced ability of ASTRO-H. A joint space partnership between Japan’s Aerospace Exploration Agency (ISAS/JAXA) and NASA’s Goddard Space Flight Center, Suzaku’s successors expected to lift the veil surrounding this mystery even more and lay the foundation for one day understanding a little more about the universe and its mysteries.

Watch an animation made by NASA’s Goddard Space Flight Center showing how black hole feedback works in quasars here.

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Read and learn more about supermassive black holes feedback mechanisms

Read and learn what astronomers have discovered concerning AGN here

Read more about galaxy IRAS F11119+3257

Discover ASTRO-H here

Learn about the discoveries of the Suzaku X-ray Satellite. 

Discover Japan’s Aerospace Exploration Agency here

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Learn more about the European Space Agency’s Herschel Infrared Space Observatory here. 

Learn what astronomers have discovered about the Monster of the Milky Way.