18 Billion Solar Mass Black Hole Rotates At 1/3 Speed Of Light

Way up in the constellation Cancer there’s a 14th magnitude speck of light you can claim in a 10-inch or larger telescope. If you saw it, you might sniff at something so insignificant, yet it represents the final farewell of chewed up stars as their remains whirl down the throat of an 18 billion solar mass black hole, one of the most massive known in the universe.

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
Artist’s view of a black hole-powered blazar (a type of quasar) lighting up the center of a remote galaxy. 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

Astronomers know the object as OJ 287, a quasar that lies 3.5 billion light years from Earth. Quasars or quasi-stellar objects light up the centers of many remote galaxies. If we could pull up for a closer look, we’d see a brilliant, flattened accretion disk composed of heated star-stuff spinning about the central black hole at extreme speeds.

An illustration of the binary black hole system in OJ287. The predictions of the model are verified by observations. Credit: University of Turku
An illustration of the binary black hole system, OJ 287, showing the massive black hole surrounded by an accretion disk. A second, smaller black hole is believed to orbit the larger. When it intersects the larger’s disk coming and going, astronomers see a pair of bright flares. The predictions of the model are verified by observations. Credit: University of Turku

As matter gets sucked down the hole, jets of hot plasma and energetic light shoot out perpendicular to the disk. And if we’re so privileged that one of those jet happens to point directly at us, we call the quasar a “blazar”. Variability of the light streaming from the heart of a blazar is so constant, the object practically flickers.

Long exposures made with the Hubble Space Telescope showing brilliant quasars flaring in the hearts of six distant galaxies. Credit: NASA/ESA
Long exposures made with the Hubble Space Telescope showing brilliant quasars flaring in the hearts of six distant galaxies. Credit: NASA/ESA

A recent observational campaign involving more than two dozen optical telescopes and NASA’s space based SWIFT X-ray telescope allowed a team of astronomers to measure very accurately the rotational rate the black hole powering OJ 287 at one third the maximum spin rate — about 56,000 miles per second (90,000 kps) —  allowed in General Relativity  A careful analysis of these observations show that OJ 287 has produced close-to-periodic optical outbursts at intervals of approximately 12 years dating back to around 1891. A close inspection of newer data sets reveals the presence of double-peaks in these outbursts.

Illustration of a gradually precessing orbit similar to the precessing orbit of the smaller smaller black hole orbiting the larger in OJ 287. Credit: Willow W / Wikipedia
Illustration of a gradually precessing orbit similar to the precessing orbit of the smaller smaller black hole orbiting the larger in OJ 287. Credit: Willow W / Wikipedia

To explain the blazar’s behavior, Prof. Mauri Valtonen of the University of Turku (Finland) and colleagues developed a model that beautifully explains the data if the quasar OJ 287 harbors not one buy two unequal mass black holes — an 18 billion mass one orbited by a smaller black hole.

OJ 287 is visible due to the streaming of matter present in the accretion disk onto the largest black hole. The smaller black hole passes through the larger’s the accretion disk during its orbit, causing the disk material to briefly heat up to very high temperatures. This heated material flows out from both sides of the accretion disk and radiates strongly for weeks, causing the double peak in brightness.

The orbit of the smaller black hole also precesses similar to how Mercury’s orbit precesses. This changes when and where the smaller black hole passes through the accretion disk.  After carefully observing eight outbursts of the black hole, the team was able to determine not only the black holes’ masses but also the precession rate of the orbit. Based on Valtonen’s model, the team predicted a flare in late November 2015, and it happened right on schedule.

OJ 287 has been fluctuating around 13.5-140 magnitude lately. You can spot in a 10-inch or larger scope in Cancer not far from the Beehive Cluster. Click the image for a detailed AAVSO finder chart. Diagram: Bob King, source: Stellarium
OJ 287 has been fluctuating around 13.5-140 magnitude lately. You can spot it in a 10-inch or larger scope in Cancer not far from the Beehive Cluster. Click the image for a detailed AAVSO finder chart. Diagram: Bob King, source: Stellarium

The timing of this bright outburst allowed Valtonen and his co-workers to directly measure the rotation rate of the more massive black hole to be nearly 1/3 the speed of light. I’ve checked around and as far as I can tell, this would make it the fastest spinning object we know of in the universe. Getting dizzy yet?

Andromeda and Milky Way Might Collide Sooner Than We Think

The merger of the Milky Way and Andromeda galaxy won’t happen for another 4 billion years, but the recent discovery of a massive halo of hot gas around Andromeda may mean our galaxies are already touching. University of Notre Dame astrophysicist Nicholas Lehner led a team of scientists using the Hubble Space Telescope to identify an enormous halo of hot, ionized gas at least 2 million light years in diameter surrounding the galaxy.

The Andromeda Galaxy is the largest member of a ragtag collection of some 54 galaxies, including the Milky Way, called the Local Group. With a trillion stars — twice as many as the Milky Way — it shines 25% brighter and can easily be seen with the naked eye from suburban and rural skies.

Quasars are distant, brilliant sources of light, believed to occur when a massive black hole in the center of a galaxy feeds on gas and stars. As the black hole consumes the material, it emits intense radiation, which is then detected as a quasar. These photos, taken by Hubble, show them as brilliant "stars" in the cores of six different galaxies. Credit: NASA/ESA
Six examples of quasars photographed with the Hubble. Quasars are distant, brilliant sources of light, believed to occur when a massive black hole in the center of a galaxy feeds on gas and stars. As the black hole consumes the material, it emits intense radiation, which is then detected as a quasar. Lehner and team measured Andromeda’s halo by studying how its gas affected the light from 18 different quasars.  Credit: NASA/ESA

Think about this for a moment. If the halo extends at least a million light years in our direction, our two galaxies are MUCH closer to touching that previously thought. Granted, we’re only talking halo interactions at first, but the two may be mingling molecules even now if our galaxy is similarly cocooned.

Lehner describes halos as the “gaseous atmospheres of galaxies”.  Despite its enormous size, Andromeda’s nimbus is virtually invisible. To find and study the halo, the team sought out quasars, distant star-like objects that radiate tremendous amounts of energy as matter funnels into the supermassive black holes in their cores. The brightest quasar, 3C273 in Virgo, can be seen in a 6-inch telescope! Their brilliant, pinpoint nature make them perfect probes.

To detect Andromeda's halo, Lehner and team studied how the light of 18 quasars (five shown here) was absorbed by the galaxy's gas. Credit: NASA
To detect Andromeda’s halo, Lehner and team studied how the light of 18 quasars (five shown here) was absorbed by the galaxy’s gas. Credit: NASA

“As the light from the quasars travels toward Hubble, the halo’s gas will absorb some of that light and make the quasar appear a little darker in just a very small wavelength range,” said J. Christopher Howk , associate professor of physics at Notre Dame and co-investigator. “By measuring the dip in brightness, we can tell how much halo gas from M31 there is between us and that quasar.”

Astronomers have observed halos around 44 other galaxies but never one as massive as Andromeda where so many quasars are available to clearly define its extent. The previous 44 were all extremely distant galaxies, with only a single quasar or data point to determine halo size and structure.

Andromeda’s close and huge with lots of quasars peppering its periphery. The team drew from about five years’ worth of observations of archived Hubble data to find many of the 18 objects needed for a good sample.

This illustration shows a stage in the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years. In this image, representing Earth's night sky in 3.75 billion years, Andromeda (left) fills the field of view and begins to distort the Milky Way with tidal pull. (Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger)
This illustration shows a stage in the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years. In this image, representing Earth’s night sky in 3.75 billion years, Andromeda (left) fills the field of view and begins to distort the Milky Way with tidal pull. Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger

The halo is estimated to contain half the mass of the stars in the Andromeda galaxy itself, in the form of a hot, diffuse gas. Simulations suggest that it formed at the same time as the rest of the galaxy. Although mostly composed of ionized hydrogen — naked protons and electrons —  Andromeda’s aura is also rich in heavier elements, probably supplied by supernovae. They erupt within the visible galaxy and violently blow good stuff like iron, silicon, oxygen and other familiar elements far into space. Over Andromeda’s lifetime, nearly half of all the heavy elements made by its stars have been expelled far beyond the galaxy’s 200,000-light-year-diameter stellar disk.

You might wonder if galactic halos might account for some or much of the still-mysterious dark matter. Probably not. While dark matter still makes up the bulk of the solid material in the universe, astronomers have been trying to account for the lack of visible matter in galaxies as well. Halos now seem a likely contributor.

The next clear night you look up to spy Andromeda, know this: It’s closer than you think!

For more on the topic, here are links to Lehner’s paper in the Astrophysical Journal and the Hubble release.

Could the Milky Way Become a Quasar?

There’s a supermassive black hole in the center of our Milky Way galaxy. Could this black hole become a Quasar?

Previously, we answered the question, “What is a Quasar”. If you haven’t watched that one yet, you might want to pause this video and click here. … or you could bravely plow on ahead because you already know or because clicking is hard.

Should you fall in the latter category. I’m here to reward your laziness. A quasar is what you get when a supermassive black hole is actively feeding on material at the core of a galaxy. The region around the black hole gets really hot and blasts out radiation that we can see billions of light-years away.

Our Milky Way is a galaxy, it has a supermassive black hole at the core. Could this black hole feed on material and become a quasar? Quasars are actually very rare events in the life of a galaxy, and they seem to happen early on in a galaxy’s evolution, when it’s young and filled with gas.

Normally material in the galactic disk orbits well away from the the supermassive black hole, and it’s starved for material. The occasional gas cloud or stray star gets too close, is torn apart, and we see a brief flash as it’s consumed. But you don’t get a quasar when a black hole is snacking on stars. You need a tremendous amount of material to pile up, so it’s chokes on all the gas, dust, planets and stars. An accretion disk grows; a swirling maelstrom of material bigger than our Solar System that’s as hot as a star. This disk creates the bright quasar, not the black hole itself.

Quasars might only happen once in the lifetime of a galaxy. And if it does occur, it only lasts for a few million years, while the black hole works through all the backed up material, like water swirling around a drain. Once the black hole has finished its “stuff buffet”, the accretion disk disappears, and the light from the quasar shuts off.

Sounds scary. According to New York University research scientist Gabe Perez-Giz, even though a quasar might be emitting more than 100 trillion times as much energy as the Sun, we’re far enough away from the core of the Milky Way that we would receive very little of it – like, one hundredth of a percent of the intensity we get from the Sun.

This annotated artist's conception illustrates our current understanding of the structure of the Milky Way galaxy. Image Credit: NASA
This annotated artist’s conception illustrates our current understanding of the structure of the Milky Way galaxy. Image Credit: NASA

Since the Milky Way is already a middle aged galaxy, its quasaring days are probably long over. However, there’s an upcoming event that might cause it to flare up again. In about 4 billion years, Andromeda is going to cuddle with the Milky Way, disrupting the cores of both galaxies. During this colossal event, the supermassive black holes in our two galaxies will interact, messing with the orbits of stars, planets, gas and dust.

Some will be thrown out into space, while others will be torn apart and fed to the black holes. And if enough material piles up, maybe our Milky Way will become a quasar after all. Which as I just mentioned, will be totally harmless to us. The galactic collision? Well that’s another story.

It’s likely our Milky Way already was a quasar, billions of years ago. And it might become one again billions of years from now. And that’s interesting enough that I think we should stick around and watch it happen. How do you feel about the prospects for our Milky Way becoming a quasar? Are you a little nervous by an event that won’t happen for another 4 billion years?

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Astronomers Catch A Quasar Shutting Off

Last week, astronomers at Yale University reported seeing something unusual: a seemingly stedfast beacon from the far reaches of the Universe went quiet. This relic light source, a quasar located in the region of our sky known as the celestial equator, unexpectedly became 6-7 times dimmer over the first decade of the 21st century. Thanks to this dramatic change in luminosity, astronomers now have an unprecedented opportunity to study both the life cycle of quasars and the galaxies that they once called home.

A quasar arises from a distant (and therefore, very old) galaxy that once contained a central, rotating supermassive black hole – what astronomers call an active galactic nucleus. This spinning beast ravenously swallowed up large amounts of ambient gas and dust, kicking up surrounding material and sending it streaming out of the galaxy at blistering speeds. Quasars shine because these ancient jets achieved tremendous energies, thereby giving rise to a torrent of light so powerful that astronomers are still able to detect it here on Earth, billions of years later.

In their hey-day, some active galactic nuclei were also energetic enough to excite electrons farther away from the central black hole. But even in the very early Universe, electrons couldn’t withstand that kind of excitement forever; the laws of physics don’t allow it. Eventually, each electron would drop back down to its rest state, releasing a photon of corresponding energy. This cycle of excitation happened over and over and over again, in regular and predictable patterns. Modern astronomers can visualize those transitions – and the energies that caused them – by examining a quasar’s optical spectrum for characteristic emission lines at certain wavelengths.

An example of an atomic spectrum, showing emission lines at particular wavelengths.
A simple example of an atomic spectrum, showing emission lines at particular wavelengths. Broad humps correspond to brighter emission lines, while lines that arise from narrow, lower-intensity emissions appear dimmer. Credit: NASA

Not all quasars are created equal, however. While the spectra of some quasars reveal many bright, broad emission lines at different energies, other quasars’ spectra consist of only the dim, narrow variety. Until now, some astronomers thought that these variations in emission lines among quasars were simply due to differences in their orientation as seen from Earth; that is, the more face-on a quasar was relative to us, the broader the emission lines astronomers would be able to see.

But all of that has now been thrown into question, thanks to our friend J015957.64+003310.5, the quasar revealed by the team of astronomers at Yale. Indeed, it is now plausible that a quasar’s pattern of emission lines simply changes over its lifetime. After gathering ten years of spectral observations from the quasar, the researchers observed its original change in brightness in 2010. In July 2014, they confirmed that it was still just as dim, disproving hypotheses that suggested the effect was simply due to intervening gas or dust. “We’ve looked at hundreds of thousands of quasars at this point, and now we’ve found one that has switched off,” explained C. Megan Urry, the study’s co-author.

How would that happen, you ask? After observing the comparable dearth of broad emission lines in its spectrum, Urry and her colleagues believe that long ago, the black hole at the heart of the quasar simply went on a diet. After all, an active galactic nucleus that consumed less material would generate less energy, giving rise to fainter particle jets and fewer excited atoms. “The power source just went dim,” said Stephanie LaMassa, the study’s principal investigator.

LaMassa continued, “Because the life cycle of a quasar is one of the big unknowns, catching one as it changes, within a human lifetime, is amazing.” And since the life cycle of quasars is dependent on the life cycle of supermassive black holes, this discovery may help astronomers to explain how those that lie at the center of most galaxies evolve over time – including Sagittarius A*, the supermassive black hole at the center of our own Milky Way.

“Even though astronomers have been studying quasars for more than 50 years, it’s exciting that someone like me, who has studied black holes for almost a decade, can find something completely new,” added LaMassa.

The team’s research will be published in an upcoming issue of The Astrophysical Journal. A pre-print of the paper is available here.

Weekly Space Hangout – Jan. 23, 2015: SpaceX, Rosetta, and Asteroid Updates!

Host: Fraser Cain (@fcain)

Guests:
Morgan Rehnberg (cosmicchatter.org / @MorganRehnberg )
Ramin Skibba (@raminskibba)
Dave Dickinson (@astroguyz / www.astroguyz.com)
Continue reading “Weekly Space Hangout – Jan. 23, 2015: SpaceX, Rosetta, and Asteroid Updates!”

Weekly Space Hangout – Jan 9, 2015: Andy Weir of “The Martian”

Host: Fraser Cain (@fcain)
Special Guest: Andy Weir , author of “The Martian”
Andy was first hired as a programmer for a national laboratory at age fifteen and has been working as a software engineer ever since. He is also a lifelong space nerd and a devoted hobbyist of subjects like relativistic physics, orbital mechanics, and the history of manned spaceflight. “The Martian” is his first novel.

Guests:
Morgan Rehnberg (cosmicchatter.org / @cosmic_chatter)
Ramin Skibba (@raminskibba)
Brian Koberlein (@briankoberlein)
Dave Dickinson (@astroguyz / www.astroguyz.com)
Nicole Gugliucci (cosmoquest.org / @noisyastronomer)
Continue reading “Weekly Space Hangout – Jan 9, 2015: Andy Weir of “The Martian””

Weekly Space Hangout – Nov. 21, 2014: New Images of Europa

Host: Fraser Cain (@fcain)

Guests:
Morgan Rehnberg (cosmicchatter.org / @cosmic_chatter)
Brian Koberlein (@briankoberlein)
Ramin Skibba (@raminskibba)
Dave Dickinson (@astroguyz / www.astroguyz.com)

Continue reading “Weekly Space Hangout – Nov. 21, 2014: New Images of Europa”

Old Equations Shed New Light on Quasars

There’s nothing more out of this world than quasi-stellar objects or more simply – quasars. These are the most powerful and among the most distant objects in the Universe. At their center is a black hole with the mass of a million or more Suns. And these powerhouses are fairly compact – about the size of our Solar System. Understanding how they came to be and how — or if — they evolve into the galaxies that surround us today are some of the big questions driving astronomers.

Now, a new paper by Yue Shen and Luis C. Ho – “The diversity of quasars unified by accretion and orientation” in the journal Nature confirms the importance of a mathematical derivation by the famous astrophysicist Sir Arthur Eddington during the first half of the 20th Century, in understanding not just stars but the properties of quasars, too. Ironically, Eddington did not believe black holes existed, but now his derivation, the Eddington Luminosity, can be used more reliably to determine important properties of quasars across vast stretches of space and time.

A quasar is recognized as an accreting (meaning- matter falling upon) super massive black hole at the center of an “active galaxy”. Most known quasars exist at distances that place them very early in the Universe; the most distant is at 13.9 billion light years, a mere 770 million years after the Big Bang. Somehow, quasars and the nascent galaxies surrounding them evolved into the galaxies present in the Universe today.  At their extreme distances, they are point-like, indistinguishable from a star except that the spectra of their light differ greatly from a star’s. Some would be as bright as our Sun if they were placed 33 light years away meaning that  they are over a trillion times more luminous than our star.

An artists illustration of the central engine of a Quasar. These "Quasi-stellar Objects" QSOs are now recognized as the super massive black holes at the center of emerging galaxies in the early Universe. (Photo Credit: NASA)
An artists illustration of the central engine of a quasar. These “Quasi-stellar Objects” QSOs are now recognized as the super massive black holes at the center of emerging galaxies in the early Universe. (Photo Credit: NASA)

The Eddington luminosity  defines the maximum luminosity that a star can exhibit that is in equilibrium; specifically, hydrostatic equilibrium. Extremely massive stars and black holes can exceed this limit but stars, to remain stable for long periods, are in hydrostatic equilibrium between their inward forces – gravity – and the outward electromagnetic forces. Such is the case of our star, the Sun, otherwise it would collapse or expand which in either case, would not have provided the stable source of light that has nourished life on Earth for billions of years.

Generally, scientific models often start simple, such as Bohr’s model of the hydrogen atom, and later observations can reveal intricacies that require more complex theory to explain, such as Quantum Mechanics for the atom. The Eddington luminosity and ratio could be compared to knowing the thermal efficiency and compression ratio of an internal combustion engine; by knowing such values, other properties follow.

Several other factors regarding the Eddington Luminosity are now known which are necessary to define the “modified Eddington luminosity” used today.

The new paper in Nature shows how the Eddington Luminosity helps understand the driving force behind the main sequence of quasars, and Shen and Ho call their work the missing definitive proof that quantifies the correlation of a quasar properties to a quasar’s Eddington ratio.

They used archival observational data to uncover the relationship between the strength of the optical Iron [Fe] and Oxygen[O III] emissions – strongly tied to the physical properties of the quasar’s central engine – a super-massive black hole, and the Eddington ratio. Their work provides the confidence and the correlations needed to move forward in our understanding of quasars and their relationship to the evolution of galaxies in the early Universe and up to our present epoch.

Astronomers have been studying quasars for a little over 50 years. Beginning in 1960, quasar discoveries began to accumulate but only through radio telescope observations. Then, a very accurate radio telescope measurement of Quasar 3C 273 was completed using a Lunar occultation. With this in hand, Dr. Maarten Schmidt of California Institute of Technology was able to identify the object in visible light using the 200 inch Palomar Telescope. Reviewing the strange spectral lines in its light, Schmidt reached the right conclusion that quasar spectra exhibit an extreme redshift and it was due to cosmological effects. The cosmological redshift of quasars meant that they are at a great distance from us in space and time. It also spelled the demise of the Steady-State theory of the Universe and gave further support to an expanding Universe that emanated from a singularity – the Big Bang.

Dr. Maarten Schmidt, Caltech University, with Donald Lynden-Bell, were the first recipients of the Kavli Prize in Astrophysics, “for their seminal contributions to understanding the nature of quasars”. While in high school, this author had the privilege to meet Dr. Schmidt at the Los Angeles Museum of Natural History after his presentation to a group of students. (Photo Credit: Caltech)
Dr. Maarten Schmidt, Caltech, with Donald Lynden-Bell, were the first recipients of the Kavli Prize in Astrophysics, “for their seminal contributions to understanding the nature of quasars”. While in high school, this author had the privilege to meet Dr. Schmidt at the Los Angeles Museum of Natural History after his presentation to a group of students. (Photo Credit: Caltech)

The researchers, Yue Shen and Luis C. Ho are from the Institute for Astronomy and Astrophysics at Peking University working with the Carnegie Observatories, Pasadena, California.

References and further reading:

“The diversity of quasars unified by accretion and orientation”, Yue Shen, Luis C. Ho, Sept 11, 2014, Nature

“What is a Quasar?”, Universe Today, Fraser Cain, August 12, 2013

“Interview with Maarten Schmidt”, Caltech Oral Histories, 1999

“Fifty Years of Quasars, a Symposium in honor of Maarten Schmidt”, Caltech, Sept 9, 2013

Observing Alert: Distant Blazar 3C 454.3 in Outburst, Visible in Amateur Telescopes

Have an 8-inch or larger telescope? Don’t mind staying up late? Excellent. Here’s a chance to stare deeper into the known fabric of the universe than perhaps you’ve ever done before. The violent blazer  3C  454.3 is throwing a fit again, undergoing its most intense outburst seen since 2010. Normally it sleeps away the months around 17th magnitude but every few years, it can brighten up to 5 magnitudes and show in amateur telescopes. While magnitude +13 doesn’t sound impressive at first blush, consider that 3C 454.3 lies 7 billion light years from Earth. When light left the quasar, the sun and planets wouldn’t have skin in the game for another  two billion years. 

If we could see the blazar 3C 354.3 up close it would look something like this. A bright accretion disk surrounds a black hole. Twin jets of radiation beam from the center. Credit: Cosmovision
If we could see the blazar 3C 354.3 up close it would look something like this. A bright accretion disk surrounds a black hole. Twin jets of radiation beam from the center. Credit: Cosmovision

Blazars form in the the cores of active galaxies where supermassive black holes reside. Matter falling into the black hole spreads into a spinning accretion disk before spiraling down the hole like water down a bathtub drain.

Superheated to millions of degrees by gravitational compression the disk glows brilliantly across the electromagnetic spectrum. Powerful spun-up magnetic fields focus twin beams of light and energetic particles called jets that blast into space perpendicular to the disk.

Blazars and quasars are thought to be one and the same, differing only by the angle at which we see them. Quasars – far more common – are actively- munching supermassive black holes seen from the side, while in blazars – far more rare – we stare directly or nearly so into the jet like looking into the beam of a flashlight.

An all-sky view in gamma ray light made with the Fermi gamma ray telescope shows bright gamma-ray emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes including the active blazar 3C 454.3 at lower left. Credit: NASA/DOE/International LAT Team
An all-sky view in gamma ray light made with the Fermi Gamma-ray Space Telescope shows bright gamma-ray emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes including the active blazar 3C 454.3 at lower left. Credit: NASA/DOE/International LAT Team

3C 454.3 is one of the top ten brightest gamma ray sources in the sky seen by the Fermi Gamma-ray Space Telescope. During its last major flare in 2005, the blazar blazed with the light of 550 billion suns. That’s more stars than the entire Milky Way galaxy! It’s still not known exactly what sets off these periodic outbursts but possible causes include radiation bursts from shocked particles within the jet or precession (twisting) of the jet bringing it close to our line of sight.

3c 454.3 is near the magnitude 2.5 magnitude star Alpha Pegasi just to the west of the Great Square. Use this chart to star hop from Alpha to IM Peg (mag. ~ 5.7). Once there, the detailed map below will guide you to the blazar. Stellarium
3c 454.3 is near the star Alpha Pegasi just to the west of the Great Square. Use this chart to star hop from Alpha to IM Peg (mag. ~ 5.7). Once there, the detailed map below will guide you to the blazar. Stellarium

The current outburst began in late May when the Italian Space Agency’s AGILE satellite detected an increase in gamma rays from the blazar. Now it’s bright visually at around magnitude +13.6 and fortunately not difficult to find, located in the constellation Pegasus near the bright star Alpha Pegasi (Markab) in the lower right corner of the Great Square asterism.

Using the wide view map, find your way to IM Peg via Markab and then make a copy of the detailed map below to use at the telescope to star hop to 3C 454.3. The blazar lies immediately south of a star of similar magnitude. If you see what looks like a ‘double star’ at the location, you’ve nailed it. Incredible isn’t it to look so far into space back to when the universe was just a teenager? Blows my mind every time.

Detailed map showing the location of the blazar 3C 454.3. I've created a small asterism with a group of brighter stars with their magnitudes marked. A scale showing 30 arc minutes (1/2 degree) is at right. Stars shown to about magnitude +15. Created with Chris Marriott's SkyMap software
Detailed map showing the location of the blazar 3C 454.3. I’ve drawn a small asterism using a group of brighter stars with their magnitudes marked. A scale showing 30 arc minutes (1/2 degree) is at right. Click to enlarge. Created with Chris Marriott’s SkyMap software

To further explore 3C 454.3 and blazars vs. quasars I encourage you to visit check out Stefan Karge’s excellent Frankfurt Quasar Monitoring site.  It’s packed with great information and maps for finding the best and brightest of this rarified group of observing targets. Karge suggests that flickering of the blazar may cause it to appear somewhat brighter or fainter than the current magnitude. You’re watching a violent event subject to rapid and erratic changes. For an in-depth study of 3C 454.3, check out the scientific paper that appeared in the 2010 Astrophysical Journal.


Learn more about quasars and blazers with a bit of great humor

Finally, I came across a wonderful video while doing research for this article I thought you’d enjoy as well.

Supermassive Black Hole’s Dizzying Spin Is Half The Speed Of Light

The spin rate of the most distant supermassive black hole has been measured directly, and wow, is it fast. X-ray observations of  RX J1131-1231 (RX J1131 for short) show it is whizzing around at almost half the speed of light. Through X-rays, the astronomers were able to peer at the rate of debris fall into the singularity, yielding the speed measurement.

“We estimate that the X-rays are coming from a region in the disk located only about three times the radius of the event horizon — the point of no return for infalling matter,” stated Jon Miller, an an associate professor of astronomy at the University of Michigan and a co-author on the paper. “The black hole must be spinning extremely rapidly to allow a disk to survive at such a small radius.”

Supermassive black holes are embedded in the heart of most galaxies, and are millions or even billions of times for massive than the Sun. This makes the spin speed astonishingly fast, but also gives astronomers clues about how the host galaxy evolved.

“The growth history of a supermassive black hole is encoded in its spin, so studies of spin versus time can allow us study the co-evolution of black holes and their host galaxies,” stated Mark Reynolds, an assistant research scientist in astronomy at University of Michigan, another co-author on the study.

An artist's conception of jets protruding from a quasar. Credit: ESO/M. Kornmesser
An artist’s conception of jets protruding from a quasar. Credit: ESO/M. Kornmesser

RX J1131 is six billion light-years away from Earth and classified as a quasar, a type of object that occurs when a lot of matter plunges into a supermassive black hole.

“Under normal circumstances, this faraway quasar would be too faint to study. But the researchers were able to take advantage of a sort of natural telescope effect known as gravitational lensing and a lucky alignment of the quasar and a giant elliptical galaxy to get a closer view,” the University of Michigan stated.

“Gravitational lensing, first predicted by Einstein, occurs when the gravity of massive objects acts as a lens to bend, distort and magnify the light from more distant objects as it passes.”

In this case, the researchers used the Chandra X-ray Observatory and the European Space Agency’s XMM-Newton Telescope to capture the X-ray images.

The research was led Rubens Reis, a postdoctoral research fellow in astronomy the University of Michigan. The paper is published today (March 5) in Nature.

For further reading, see the Chandra website and the associated NASA press release.

Source: University of Michigan