Spooky alignment of quasars across billions of light-years

Researchers have found that the rotation axes of super-massive black holes of some quasars are parallel to each other.

Quasar spin axes — Artist’s impression of the mysterious alignments between the spin axes of quasars and the large-scale structures that they inhabit. These alignments are over billions of light-years and are the largest known in the universe. The large-scale structure is shown in blue and quasars are marked in white with the rotation axes of their black holes indicated with a line. (Credit: ESO/M. Kornmesser)

New observations with the European Southern Observatory’s Very Large Telescope (VLT) in Chile have revealed alignments of the largest structures ever discovered in the universe. A team led by Damien Hutsemékers from the University of Liège in Belgium has found that the rotation axes of the central super-massive black holes in a sample of quasars are parallel to each other over distances of billions of light-years. The team also has found that the rotation axes of these quasars tend to be aligned with the vast structures in the cosmic web in which they reside.

Quasars are very active super-massive black holes at the nuclei of galaxies. These black holes are surrounded by spinning disks of extremely hot material that is often spewed out in long jets along their axes of rotation. Quasars can shine more brightly than all the stars in the rest of their host galaxies put together.

How Quasars are Powered (Credit: Nature)

“The first odd thing we noticed was that some of the quasars’ rotation axes were aligned with each other, despite the fact that these quasars are separated by billions of light-years,” said Damien Hutsemékers from the University of Liège in Belgium. His team used the FORS instrument on the VLT to study 93 quasars that were known to form huge groupings spread over billions of light-years, seen at a time when the universe was about one-third of its current age.

Hutsemékers says, “Our data provide the first observational confirmation of this effect, on scales much larger that what had been observed to date for normal galaxies.”

The team then went further and looked to see if the rotation axes were linked, not just to each other, but also to the structure of the universe on large scales at that time.

When astronomers look at the distribution of galaxies on scales of billions of light-years, they find that they are not evenly distributed. They form a cosmic web of filaments and clumps around huge voids where galaxies are scarce. This intriguing and beautiful arrangement of material is known as large-scale structure.

Dr. Hutsemekers and his colleagues found that the spin axes of the quasars were linked not just to each other, but also tend to be parallel to their host large-scale structures. The new VLT results indicate that the rotation axes of the quasars tend to be parallel to the large-scale structures in which they find themselves.

A false-color image from the W. M. Keck Observatory in Hawaii shows the first observed triple quasar—a trio of enormous, hyperactive black holes in close proximity to each other. The three quasars are 10.5 billion light-years away from Earth, meaning that the light being recorded is actually a glimpse into the early universe. (Credit: S. G. Djorgovski et al., Caltech, EPFL ) — A false-color image of a trio of enormous, hyperactive black holes in close proximity to each other. The three quasars are 10.5 billion light-years away from Earth, thus the light being recorded is actually a glimpse into the early universe. (Credit: S. G. Djorgovski et al., Caltech, EPFL )

So, if the quasars are in a long filament, then the spins of the central black holes will point along the filament. The researchers estimate that the probability that these alignments are simply the result of chance is less than 1 percent.

“A correlation between the orientation of quasars and the structure they belong to is an important prediction of numerical models of evolution of our Universe. Our data provide the first observational confirmation of this effect, on scales much larger that what had been observed to date for normal galaxies,” said Dominique Sluse of the Argelander-Institut für Astronomie in Bonn, Germany.

This artist’s impression shows how ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun, may have looked. This quasar is the most distant yet found and is seen as it was just 770 million years after the Big Bang. This object is by far the brightest object yet discovered in the early Universe. (Credit: Wikipedia) — Artist’s impression of ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun. This quasar is the most distant yet found and is seen as it was just 770 million years after the Big Bang. This object is by far the brightest object yet discovered in the early Universe. (Credit: Wikipedia)

The team could not see the rotation axes or the jets of the quasars directly. Instead they measured the polarization of the light from each quasar and, for 19 of them, found a significantly polarized signal. The direction of this polarization, combined with other information, could be used to deduce the angle of the accretion disk and hence the direction of the spin axis of the quasar.

“The alignments in the new data, on scales even bigger than current predictions from simulations, may be a hint that there is a missing ingredient in our current models of the cosmos,” concludes Dominique Sluse.

The Chandra X-ray image is of the quasar PKS 1127-145, a highly luminous source of X-rays and visible light about 10 billion light years from Earth. An enormous X-ray jet extends at least a million light years from the quasar. Image is 60 arcsec on a side. RA 11h 30m 7.10s Dec -14° 49' 27" in Crater. Observation date: May 28, 2000. Instrument: ACIS. — The Chandra X-ray image is of the quasar PKS 1127-145, a highly luminous source of X-rays and visible light about 10 billion light years from Earth. An enormous X-ray jet extends at least a million light years from the quasar. Image is 60 arcsec on a side. RA 11h 30m 7.10s Dec -14° 49′ 27″ in Crater. Observation date: May 28, 2000. Instrument: ACIS.

D. Hutsemekers et al. 2014. Alignment of quasar polarizations with large-scale structures. A&A 572, A18; doi: 10.1051/0004-6361/201424631(PDF)

Credit: ESO.org,Hutsemékers,Sluse,Hook

What happens when you point a telescope designed to investigate black holes at the sun?

An image captured by NASA’s NuSTAR telescope, designed to investigate black holes, is the best-ever view of the sun in high-energy X-ray light.

X-rays stream off the sun in this image showing observations from by NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, overlaid on a picture taken by NASA's Solar Dynamics Observatory (SDO).This image shows that some of the hotter emission tracked by NuSTAR is coming from different locations in the active regions and the coronal loops than the cooler emission shown in the SDO image. (Credit: NASA/JPL-Caltech ) — This image shows that some of the hotter emission tracked by NuSTAR is coming from different locations in the active regions and the coronal loops than the cooler emission shown in the SDO image. (Credit: NASA/JPL-Caltech

For the first time, a mission designed to set its eyes on black holes and other objects far from our solar system has turned its gaze back closer to home, capturing images of our sun. NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, has taken its first picture of the sun, producing the most sensitive solar portrait ever taken in high-energy X-rays.

“NuSTAR will give us a unique look at the sun, from the deepest to the highest parts of its atmosphere,” said David Smith, a solar physicist and member of the NuSTAR team at University of California, Santa Cruz.

NuSTAR spacecraft will allow astronomers to study the universe in high energy X-rays. Here it undergoes a solar array illumination test. Image tweeted Feb. 3, 2012. (Credit: NASA/NuStar) — NuSTAR spacecraft undergoes a solar array illumination test. Image tweeted Feb. 3, 2012. (Credit: NASA/NuStar)

Solar scientists first thought of using NuSTAR to study the sun about seven years ago, after the space telescope’s design and construction was already underway (the telescope launched into space in 2012). Smith had contacted the principal investigator, Fiona Harrison of the California Institute of Technology in Pasadena, who mulled it over and became excited by the idea.

“At first I thought the whole idea was crazy,” says Harrison. “Why would we have the most sensitive high energy X-ray telescope ever built, designed to peer deep into the universe, look at something in our own back yard?” Smith eventually convinced Harrison, explaining that faint X-ray flashes predicted by theorists could only be seen by NuSTAR.

nustar20120613-640 — NASA’s NuSTAR and its rocket drop from the carrier “Stargazer” plane. (Credit: Orbital Sciences Corporation)

While the sun is too bright for other telescopes such as NASA’s Chandra X-ray Observatory, NuSTAR can safely look at it without the risk of damaging its detectors. The sun is not as bright in the higher-energy X-rays detected by NuSTAR, a factor that depends on the temperature of the sun’s atmosphere.

This first solar image from NuSTAR demonstrates that the telescope can in fact gather data about sun. And it gives insight into questions about the remarkably high temperatures that are found above sunspots — cool, dark patches on the sun. Future images will provide even better data as the sun winds down in its solar cycle.

“We will come into our own when the sun gets quiet,” said Smith, explaining that the sun’s activity will dwindle over the next few years.

With NuSTAR’s high-energy views, it has the potential to capture hypothesized nanoflares — smaller versions of the sun’s giant flares that erupt with charged particles and high-energy radiation. Nanoflares, should they exist, may explain why the sun’s outer atmosphere, called the corona, is sizzling hot, a mystery called the “coronal heating problem.” The corona is, on average, 1.8 million degrees Fahrenheit (1 million degrees Celsius), while the surface of the sun is relatively cooler at 10,800 Fahrenheit (6,000 degrees Celsius). It is like a flame coming out of an ice cube. Nanoflares, in combination with flares, may be sources of the intense heat.

If NuSTAR can catch nanoflares in action, it may help solve this decades-old puzzle.

“NuSTAR will be exquisitely sensitive to the faintest X-ray activity happening in the solar atmosphere, and that includes possible nanoflares,” said Smith.

What’s more, the X-ray observatory can search for hypothesized dark matter particles called axions. Dark matter is five times more abundant than regular matter in the universe. Everyday matter familiar to us, for example in tables and chairs, planets and stars, is only a sliver of what’s out there. While dark matter has been indirectly detected through its gravitational pull, its composition remains unknown.

In 1977, Frank Wilczek proposed the existence of a new type of elementary particle. He named it an “axion”, after a brand of detergent, because it cleaned up a profound physical problem. (Credit: indico.cern.ch)

It’s a long shot, say scientists, but NuSTAR may be able spot axions, one of the leading candidates for dark matter, should they exist. The axions would appear as a spot of X-rays in the center of the sun.

Meanwhile, as the sun awaits future NuSTAR observations, the telescope is continuing with its galactic pursuits, probing black holes, supernova remnants and other extreme objects beyond our solar system.

NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) space telescope will launch in 2012 on a mission to seek out distant black holes like never before. Take a look at how the $165 million space telescope will launch and perform its mission (Credit: in the SPACE.com) — NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) space telescope launched in 2012 on a mission to seek out distant black holes like never before. (Credit: in the SPACE.com)

Credit: NuStar News at Caltech

Starburst Galaxies emit more radiation than a million suns emit at all wavelengths

Ultra-luminous X-Ray Sources in Starburst Galaxies

The Antennae Galaxies are an example of a starburst galaxy occurring from the collision of NGC 4038/NGC 4039. (Credit: NASA/ESA)

Ultra-luminous X-ray sources (ULXs) are point sources in the sky that are so bright in X-rays that each emits more radiation than a million suns emit at all wavelengths. ULXs are rare. Most galaxies (including our own Milky Way) have none, and those galaxies that do host a ULX usually contain only one. ULXs are also mysterious objects. They can’t be normal stars because their huge luminosities should then tear them apart.

Most astronomers think that ULXs are black holes more than about ten solar masses in size (so-called intermediate mass black holes) that are accreting matter onto a surrounding disk and emitting X-rays. Bright X-ray emission is not unusual – the nuclei of galaxies also are bright X-ray emitters – but they are super-massive black holes, while ULXs are neither super-massive nor located in galactic nuclei.

An artist's rendition of one of the newly discovered SPIRE 'hot starburst' galaxies (credit: NASA/CXC/M.Weiss) — An artist’s rendition of one of the newly discovered SPIRE ‘hot starburst’ galaxies (credit: NASA/CXC/M.Weiss)

CFA astronomers Stefano Mineo and Andy Goulding and their colleagues used the Chandra X-ray Observatory to search for ULXs in a sample of seventeen luminous infrared galaxies that are exceptionally bright because of their extreme star formation activity. If star formation does signal the presence of ULXs, or even produce them, then these objects should have many. The team discovered fifty-three ULXs (with an uncertainty of about 30% ) among the 139 X-ray sources present in this sample.

An Ultraluminous X-ray Source (ULX) in the center of galaxy M82 that astronomers had thought was a black hole is really the brightest pulsar ever recorded. (Credit: X-ray: NASA/CXC/Univ. of Toulouse/M. Bachetti; Optical: NOAO) — An Ultraluminous X-ray Source (ULX) in the center of galaxy M82 that astronomers had thought was a black hole is really the brightest pulsar ever recorded. (Credit:
X-ray: NASA/CXC/Univ. of Toulouse/M. Bachetti; Optical: NOAO)

They report, however, that this ULX figure is actually ten times smaller than would be expected if ULXs correlated with simple star formation activity. They offer several possible explanations for this deficiency, including a surfeit of elements heavier than helium in these galaxies (these elements can suppress the birth of black holes).

The galaxy NGC 1068, seen here in X-ray (red), optical (green) and radio (blue), is actively forming stars and contains three ultra-luminous X-ray sources ULXs. Astronomers investigating the connections between young stars and ULXs have completed a study of active star-forming galaxies and were surprised to find they are deficient in ULXs. (Credit: NASA/CXC/MIT/C.Canizares, D.Evans, Optical NASA/STScI, Radio NSF/NRAO/VLA)

But the most likely scenario, they argue, is that large amounts of gas in these galaxies are present and absorbing X-rays, with the result that many of the ULXs present are not detected. Their conclusion implies that deep X-ray surveys of galaxies must take absorbing gas into account when estimating their internal X-ray properties and how this radiation affects the galaxies’ properties and evolution.

Reference(s):

“A Deficit of Ultraluminous X-ray Sources in Luminous Infrared Galaxies,” W. Luangtip, T. P. Roberts, S. Mineo, B. D. Lehmer, D. M. Alexander, F. E. Jackson, A. D. Goulding and J. L. Fischer, MNRAS 446, 470, 2015

Credit: Smithsonian Astrophysical Observatory

Why Our Galaxy’s Black Hole Didn’t Eat Mystery Object

Latest research suggests enormous black hole drove two binary stars to merge into one

Screenshot of a simulation depicting the G2 black hole encounter... before astronomers realized G2 isn't quite what it seemed. (Credit: LECHO/MPE/M. Schartmann/L. Calçada) — Screenshot of a simulation depicting the G2 black hole encounter before astronomers realized G2 isn’t quite what it seemed. (Credit: LECHO/MPE/M. Schartmann/L. Calçada, O’Neil)

Having studied it during its closest approach to the black hole this summer, UCLA astronomers believe that they have solved the riddle of the object widely known as G2. A team led by Andrea Ghez, professor of physics and astronomy in the UCLA College, determined that G2 is most likely a pair of binary stars that had been orbiting the black hole in tandem and merged together into an extremely large star, cloaked in gas and dust — its movements choreographed by the black hole’s power.

Telescopes at the Keck Observatory use adaptive optics, which enabled UCLA astronomers to discover that G2 is a pair of binary stars that merged together. (Credit: Ethan Tweedie)

Astronomers had figured that if G2 had been a hydrogen cloud, it could have been torn apart by the black hole, and that the resulting celestial fireworks would have dramatically changed the state of the black hole.

Ghez and her colleagues — who include lead author Gunther Witzel, a UCLA postdoctoral scholar, and Mark Morris and Eric Becklin, both UCLA professors of physics and astronomy — conducted the research at Hawaii’s W.M. Keck Observatory, which houses the world’s two largest optical and infrared telescopes.

Ghez said G2 now is undergoing what she calls a “spaghetti-fication” — a common phenomenon near black holes in which large objects become elongated. At the same time, the gas at G2’s surface is being heated by stars around it, creating an enormous cloud of gas and dust that has shrouded most of the massive star.

“We are seeing phenomena about black holes that you can’t watch anywhere else in the universe,” Ghez added. “We are starting to understand the physics of black holes in a way that has never been possible before.” (Credit: Stuart Wolpert)

via ucla

First Simulated Images of Two Black Holes Colliding

The equations of general relativity are so fiendish that nobody has been able to work out what a collision between two black holes would look like, until now… (PDF)

1*iAWwG2aymR3TmMH1fXpcfA — Lensing caused by various analytic spacetimes. For all panels, we use Figure 3 as a background, oriented such that the camera is pointed at the white reference dot. The camera has a 60 degree feld of view and is at a distance of 15 Schwarzschild radii from the origin measured using Kerr- Schild coordinates. The top row shows Minkowski and Schwarzschild spacetimes. The bottom row shows two views of the Kerr spacetime, with dimensionless spin x = 0.95, viewed with the camera pointing parallel to the spin axis of the black hole (bottom left) and perpendicular to the spin axis (bottom right). (Credit: A. Bohn, F. Hebert, W. Throwe, D. Bunadar, K. Henriksson, M. Scheel, N. Taylor)

The difficult part of this work is calculating the trajectory of the photons using the physics of general relativity. These equations are notoriously non-linear, so physicist sometimes simplify them by assuming that a system remains constant in the time it takes for light to pass by. The difficulty with black hole binaries is that this assumption does not hold— these objects orbit so rapidly as they approach each other that space-time warps, even during the time it takes for light to pass by.

A BBH system of equal-mass black holes with no spin, viewed near merger with the orbital angular momentum out of the page. (Credit: A. Bohn, F. Hebert, W. Throwe, D. Bunadar, K. Henriksson, M. Scheel, N. Taylor)

Andy Bohn(et al.) at Cornell University in Ithaca, New York, reveals how in-spiraling black hole pairs should distort the light field around them. The team has concluded that from large distances, binaries are more or less indistinguishable from single black holes. Only a relatively close observer would be able to see the fascinating detail that they have simulating or one with very high resolving power.

The first observation of much bigger deflections, such as those produced by black holes or black hole pairs, will be something of a triumph for whoever spots them first.

via physics arxiv

Researchers have found that the rotation axes of super-massive black holes of some quasars are parallel to each other.

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