Sitting in the arms of Cassiopeia (The Seated Queen)
Space news (galaxy evolution: unusual galaxies; spiral galaxy NGC 278) – 38 million light-years away, sitting in the arms of northern constellation Cassiopeia (The Seated Queen) –
The image above shows spiral galaxy NGC 278, a very unusual island universe astronomers are currently studying looking for clues to its unique nature. This unusual galaxy looks quiet and serene from here, but there’s unusual starburst activity taking place astronomers are currently trying to explain.
Each of the unmistakable blue knots seen strewn across NGC 278’s spiral arms is a clump of hot, newly born stars. These blue knots of young stars doesn’t extend to the outer edges of the galaxy but only reside within an inner ring some 6,500 light-years across. The two-tiered structure astronomers have identified within NGC 278 shows a bright galactic center, with much darker outer regions.
Astrophysicists studying this unusual spiral galaxy think this weird two-tiered structure and current starburst activity is due to a recent merger with a smaller, gas-rich galaxy. A merger that has ignited starburst within the center of this island universe, while the leftovers of the galactic snack dispersed into its outer regions. This activity created the ring of blue knots of newly formed stars seen here, which astronomers have dubbed a nuclear ring. A very unusual structure not often observed in galaxies with a bar across their center region. Making NGC 278 an unusual, intriguing galactic specimen they plan on studying closer for clues to its unusual nature.
With 10 times the mass than first estimates and a younger inner region than outer, this out-of-the-way galaxy appears to be composed of assorted parts from other island universes
Space news (astrophysics: unusual, rare galaxy types; UGC 1382) – 250 million light-years from Earth in an out-of-the-way, isolated little corner of the cosmos –
Living in a suburban neighborhood of an out-of-the-way little town or city is beneficial if you want to stop change due to foreign influences and exchanges. In a similar way, astronomers believe humongous, bizarre galaxy UGC 1382 kept its stunning size and the backward ages of its inner and outer components. At around 720,000 light-years across its more than seven times wider than the Milky Way and one of the largest isolated galaxies detected during the human journey to the beginning of space and time. The inner regions of this unusual galaxy are also younger than its outer parts, which would be like finding a tree whose inner growth rings are younger than its outer rings. It’s like UGC 1382 was put together from different parts of other galaxies that are held together by a delicate balance between processes and forces. An equilibrium scientists study in order to gain more understanding and knowledge of the evolution of galaxies and the universe.
“This rare, ‘Frankenstein’ galaxy formed and is able to survive because it lies in a quiet little suburban neighborhood of the universe, where none of the hubbub of the more crowded parts can bother it,” said study co-author Mark Seibert of the Observatories of the Carnegie Institution for Science, Pasadena, California. “It is so delicate that a slight nudge from a neighbor would cause it to disintegrate.”
Seibert and graduate student Lea Hagen discovered the massive size and backward ages of the inner and outer portions of UGC 1382 while looking at images of the galaxy taken by NASA’s Galaxy Evolution Explorer (GALEX) in ultraviolet wavelengths. They had been searching for data on star formation in average elliptical galaxies, instead, a titan with intangible arms extending far outside UGC 1382 emerged from the darkness.
“We saw spiral arms extending far outside this galaxy, which no one had noticed before, and which elliptical galaxies should not have,” said Hagen, who led the study. “That put us on an expedition to find out what this galaxy is and how it formed.”
Painstakingly searching through data of the galaxy obtained by a team of telescopes astronomers built a new model of the structure and dimensions of this mysterious behemoth. Spanning nearly 720,000 light-years, UGC 1382 is one of the largest galaxies ever discovered. Very few new stars form in this island universe because gas is spread thinly along its rotating disk. Astronomers are studying the history of star formation and evolution of this unusual galaxy looking for clues to explain the mysteries uncovered.
The most tantalizing clue’s the relative ages of the various parts of galaxy UGC 1382 are backward compared to previous galaxies observed during the human journey to the beginning of space and time. Normally, astrophysicists expect to see new star formation primarily in the outer, newer regions of a galaxy, while the older, inner regions contain mainly older stars. By combining data collected by the team, scientists determined the unusual structure and evolution of star formation in this massive galaxy.
“The center of UGC 1382 is actually younger than the spiral disk surrounding it,” Seibert said. “It’s old on the outside and young on the inside. This is like finding a tree whose inner growth rings are younger than the outer rings.”
The final conclusion
Astronomers think this unique galaxy resulted around 3 billion years ago when two smaller galaxies began orbiting a larger, possibly lenticular galaxy, which eventually settled into current galaxy UGC 1382. They continue to study this unusual galaxy looking for additional clues to explain its unique structure and evolution compared to other members of the Galaxy Zoo. This data will enable the search for more examples of this galaxy to help explain its unusual structure and evolution.
“By understanding this galaxy, we can get clues to how galaxies form on a larger scale, and uncover more galactic neighborhood surprises,” Hagen said.
Lenticular galaxy changing into a less defined elliptical galaxy
Space news (The evolution of galaxies: transition periods; lenticular galaxies) – 140 million light-years away toward the constellation Virgo –
The Hubble Space Telescope image of lenticular galaxy NGC 5010 seen here shows an older spiral galaxy in transition to an elliptical type. Lenticular type galaxies are considered a transition phase between spiral and elliptical galaxies. Presently, it has characteristics astronomers find in both spiral and elliptical galaxies, but will eventually evolve into a less defined elliptical galaxy.
All of the blue, fast-living stars that existed in spiral galaxy NGC 5010 have aged into older red stars as it transitioned into a lenticular galaxy. The vast majority of stars seen in this image are red and elderly, with only a few younger, blue stars sprinkled like fairy dust across dark, dusty, remnants of spiral arms. It has also started to develop a bigger bulge in its disk as it starts to take on a more rounded shape characteristic of lenticular and sometimes elliptical galaxies.
The orientation of the galaxy’s sideways to the telescope in this image. View elliptical galaxy NGC 5010 far in the future from the same reference point and older, red stars will exist within it. It could have a circular, long, narrow or even cigar shape since all are characteristic of elliptical galaxies. No matter its shape, this elliptical galaxy will contain even less gas and dust than it did when it was younger and brighter.
Heralding the growth of monster black holes pulling in surrounding material while belching out the cosmic x-ray background
Space news (astrophysics: x-ray bursts; detecting high-energy x-rays emitted by supermassive black holes) – searching the COSMOS field for elusive, high-energy x-rays with a high-pitched voice –
Astronomers searching for elusive, high-energy x-rays emitted by supermassive black holes recently made a discovery using NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR). A chorus of high-energy x-rays emitted by millions of supermassive black holes hidden within the cores of galaxies spread across a field of galaxies called the COSMOS field. Singing the elusive, high-pitched song of a phenomenon scientists call the cosmic x-ray background they emitted when they pulled surrounding matter closer. A significant step in resolving the high-energy x-ray background and understanding more about the feeding habits of supermassive black holes as they grow and evolve.
“We’ve gone from resolving just two percent of the high-energy X-ray background to 35 percent,” said Fiona Harrison, the principal investigator of NuSTAR at Caltech in Pasadena and lead author of a new study describing the findings in an upcoming issue of The Astrophysical Journal. “We can see the most obscured black holes, hidden in thick gas and dust.”
The Monster of the Milky Way, the supermassive black hole believed to reside at the core of our galaxy, bulked up by siphoning off surrounding gas and dust in the past and will continue to grow. The data obtained here by NASA’s NuSTAR will help scientists learn more concerning the growth and evolution of black holes and our host galaxy. It will also give astrophysicists more insight into the processes involved the next time the Monster of the Milky Way wakes up and decides to have a little snack.
“Before NuSTAR, the X-ray background in high energies was just one blur with no resolved sources,” said Harrison. “To untangle what’s going on, you have to pinpoint and count up the individual sources of the X-rays.”
NASA’s NuSTAR’s the first telescope capable of focusing high-energy x-rays into a sharp image, but it only gives us part of the picture. Additional research’s required to clear up the picture a little more and give us a better view of the real singers in the choir. NuSTAR should allow astronomers to decipher individual voices of x-ray singers in one of the cosmos’ rowdiest choirs.
“We knew this cosmic choir had a strong high-pitched component, but we still don’t know if it comes from a lot of smaller, quiet singers, or a few with loud voices,” said co-author Daniel Stern, the project scientist for NuSTAR at NASA’s Jet Propulsion Laboratory in Pasadena, California. “Now, thanks to NuSTAR, we’re gaining a better understanding of the black holes and starting to address these questions.”
Astronomers plan on collecting more data on the high-energy x-ray choir of the COSMOS field, which should help clear up a few mysteries surrounding the birth, growth, and evolution of black holes. Hopefully, it gives also gives us more clues to many of the mysteries we discover during the human journey to the beginning of space and time.
Produces shocks that accelerate particles, illuminating the colliding material
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.
Can blow star-forming gas 1000 light-years out of core region of host galaxies
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.
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 MarcioMeléndez, 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.”
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.
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.
Revealing the youthful glow of blue star clusters and a dusty core hidden from view
Space news (astrophysics: giant elliptical galaxies; Centaurus A) – 11 million light-years from Earth toward the constellation Centaurus (NGC 5128) –
The closest galaxy to Earth with an active nucleus containing a supermassive black hole that ejects jets of high-speed, extremely energetic particles into space, the giant elliptical island universe Centaurus A’s (NGC 5128) a nearby laboratory in which astronomers test present theories.
The stunning Hubble Space Telescope image of Centaurus A (above) reveals a scene resembling cosmic clouds on a stormy day. Dark lanes of gas and dust crisscross its warped disk, revealing the youthful glow of blue star clusters, and red patches indicating shockwaves from a recent merger with a spiral galaxy. Shockwaves that cause hydrogen gas clouds to contract, starting the process of new star formation.
The startling composite image of Centaurus A above combines X-ray data from NASA’s Chandra Observatory, optical data from the European Southern Observatory’s Very Large Telescope, and the National Radio Astronomy Observatory’s Very Large Array. The core of NGC 5128 is a mess of gas, dust, and stars in visible light, but X-rays and radio waves reveal a stunning jet of high-speed, extremely energetic particles emanating from its active nucleus.
What could power such an event?
The power source for the relativistic jets observed streaming from the active galactic nucleus of Centaurus A’s a supermassive black hole with the estimated mass of over 10 million suns. Beaming out from the galactic nucleus toward the upper left, the high-speed jet travels nearly 13,000 light-years, while a shorter jet shoots from the core in the opposing direction. Astronomers think the source of the chaos in active galaxy Centaurus A’s the noted collision with a spiral galaxy about 100 million years ago.
The amazing high-energy, extremely-fast, 30,000 light-year-long particle jet is the most striking feature in the false-color X-ray image taken by the Chandra Observatory. Beaming upward toward the left corner of the image, the relativistic jet seems to blast from the core of Centaurus A. A core containing an active, monster black hole pulling nearby matter into the center of its gravity well. An unknown realm mankind dreams about visiting one day.
You can learn more about supermassive black holes here.