Organic Molecules Endure Intense Radiation near Supermassive Black Hole

ellow: cyanoacetylene (HC3N), Red: carbon monosulfide (CS), Blue: carbon monoxide (CO), which are observed with ALMA. While HC3N is abundant in the central part of the galaxy (CND), CO is mainly distributed in the starburst ring. CS is distributed both in the CND and the starburst ring. (ALMA (ESO/NAOJ/NRAO), S. Takano et al., NASA/ESA Hubble Space Telescope and A. van der Hoeven) — The central part of the galaxy M77, also known as NGC 1068. HC3N is abundant in the central part of the galaxy (CND), CO is mainly distributed in the starburst ring. CS is distributed both in the CND and the starburst ring. (Credit: ALMA (ESO/NAOJ/NRAO), S. Takano et al., NASA/ESA Hubble & A. van der Hoeven)

Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered regions where certain organic molecules somehow endure the intense radiation near the supermassive black hole at the center of galaxy NGC 1068, also known to amateur stargazers as M77.

Such complex carbon-based molecules are thought to be easily obliterated by the strong X-rays and ultraviolet (UV) photons that permeate the environment surrounding supermassive black holes. The new ALMA data indicate, however, that pockets of calm exist even in this tumultuous region, most likely due to dense areas of dust and gas that shield molecules from otherwise lethal radiation.

View of ALMA from a hexacopter. (Credit: EFE/Ariel Marinkovic)

ALMA Observations Trace Molecules

To better understand the complex and energetic environments around a supermassive black hole, the research team, led by Shuro Takano at the National Astronomical Observatory of Japan (NAOJ) and Taku Nakajima at Nagoya University, observed the spiral galaxy M77, which is located about 47 million light-years from Earth in the direction of the constellation Cetus the Whale.

This galaxy is known to have an actively feeding central black hole, which indicates it has a substantial circumnuclear disk. That disk, in turn, is surrounded by a 3,500 light-year wide starburst ring. To probe these areas, the research team added ALMA’s extreme sensitivity and high-fidelity imaging capabilities to earlier observations conducted by the 45-meter radio telescope at the National Astronomical Observatory of Japan.

45-meter radio telescope at the Nobeyama Radio Observatory of the National Astronomical Observatory of Japan (NAOJ). — The 45-meter radio telescope’s capabilities at the Nobeyama Radio Observatory of the National Astronomical Observatory of Japan (NAOJ) were used by Dr. Shuro Takano et al. (Credit: Wiki Commons)

The new ALMA observations clearly reveal the distributions of nine types of molecules in the surrounding disk and starburst ring.

“In this observation, we used only 16 antennas, which are about one-fourth of the complete number of ALMA antennas, but it was really surprising that we could get so many molecular distribution maps in less than two hours. We have never obtained such a quantity of maps in one observation,” said Takano, the leader of the research team.

The central part of the galaxy M77, also known as NGC 1068, observed by ALMA and the NASA/ESA Hubble Space Telescope. Yellow: cyanoacetylene (HC3N), Red: carbon monosulfide (CS), Blue: carbon monoxide (CO), which are observed with ALMA. While HC3N is abundant in the central part of the galaxy (CND), CO is mainly distributed in the starburst ring. CS is distributed both in the CND and the starburst ring. Credit: ALMA(ESO/NAOJ/NRAO), S. Takano et al., NASA/ESA Hubble Space Telescope — Galaxy M77, also known as NGC 1068. Yellow: cyanoacetylene (HC3N), Red: carbon monosulfide (CS), Blue: carbon monoxide (CO), which are observed with ALMA. (Credit: ALMA(ESO/NAOJ/NRAO), S. Takano et al., NASA/ESA Hubble Telescope)

The results clearly show that the molecular distribution varies according to the type of molecule. While carbon monoxide (CO) is distributed mainly in the starburst ring, five types of molecules, including complex organic molecules such as cyanoacetylene (HC3N) and acetonitrile (CH3CN), are concentrated primarily in the CND. In addition, carbon monosulfide (CS) and methanol (CH3OH) are distributed both in the starburst ring and the CND.

Shielding Complex Organics around a Black Hole

As the supermassive black hole devours the surrounding material, this disk is heated to such extreme temperatures that it emits intense X-rays and UV photons. When complex organic molecules are exposed to these photons, their atomic bonds are broken and the molecules are destroyed. Astronomers assumed that such regions would therefore be devoid of such complex organics.

The ALMA observations, however, proved the contrary: Complex organic molecules are abundant in the CND, though not so in the broader starburst region.

“It was quite unexpected that complex molecules with a large number of atoms like acetonitrile and cyanoacetylene are concentrated around the black hole’s disk,” said Nakajima.

Dr. Shuro Takano (Credit: Mr. Matsunaga, S. Takano)

The research team speculates that organic molecules remain intact in the CND due to the large amount of gas there, which acts as a barrier for the X-rays and UV photons, while organic molecules cannot survive the exposure to the strong UV photons in the starburst region where the gas density is comparatively lower.

The researchers point out that these results are a significant first step in understanding the structure, temperature, and density of gas surrounding the active black hole in M77. “We expect that future observations with wider bandwidth and higher resolution will show us the whole picture of this region,” said Takano.

“ALMA has launched an entirely new era in astrochemistry,” said Eric Herbst of the University of Virginia in Charlottesville and a member of the research team. “Detecting and tracing molecules throughout the cosmos enables us to learn so much more about otherwise hidden areas, like the regions surrounding the black hole in M77.”

Credit: Alma Observatory, Charles Blue, NRAO Public Information Officer

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

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