From ALMA: “ALMA Witness Planet Formation in Action”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

From ALMA

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory
, Tokyo – Japan
Phone: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp

Bárbara Ferreira
ESO Public Information Officer
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: pio@eso.org

Iris Nijman
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USA
Cell phone: +1 (434) 249 3423
Email: alma-pr@nrao.edu

Artist’s impression of gas flowing like a waterfall into a protoplanetary disk gap, which is most likely caused by an infant planet. Credit: NRAO/AUI/NSF, S. Dagnello.

Scientists measured the motion of gas (arrows) in a protoplanetary disk in three directions: rotating around the star, towards or away from the star, and up- or downwards in the disk. The inset shows a close-up of where a planet in orbit around the star pushes the gas and dust aside, opening a gap. Credit: NRAO/AUI/NSF, B. Saxton.

A computer simulation showed that the patterns of gas flows are unique and are most likely caused by planets in three locations in the disk. Planets in orbit around the star push the gas and dust aside, opening gaps. The gas above the gaps collapses into it like a waterfall, causing a rotational flow of gas in the disk. Credit: ALMA (ESO/NAOJ/NRAO), J. Bae; NRAO/AUI/NSF, S. Dagnello.

For the first time, astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have witnessed 3D motions of gas in a planet-forming disk. At three locations in the disk around a young star called HD 163296, gas is flowing like a waterfall into gaps that are most likely caused by planets in formation. These gas flows have long been predicted and would directly influence the chemical composition of planets atmospheres. This research appears in the latest issue of the journal Nature.

The birthplaces of planets are disks made out of gas and dust. Astronomers study these so-called protoplanetary disks to understand the processes of planet formation. Beautiful images of disks made with ALMA show distinct gaps and ring features in the dust, which may be caused by infant planets.

To get more certainty that planets cause these gaps, and to get a complete view of planetary formation, scientists study the gas in the disks in addition to dust. Ninety-nine percent of a protoplanetary disk’s mass is gas, of which carbon monoxide (CO) is the brightest component, and ALMA can observe it.

Last year, two teams of astronomers demonstrated a new planet-hunting technique using this gas. They measured the velocity of CO gas rotating in the disk around the young star HD 163296. Localized disturbances in the movements of the gas revealed three planet-like patterns in the disk.

In this new study, lead author Richard Teague from the University of Michigan and his team used new high-resolution ALMA data from the Disk Substructures at High Angular Resolution Project (DSHARP) to study the gas’s velocity in more detail. “With the high-fidelity data from this program, we were able to measure the gas’s velocity in three directions instead of just one,” said Teague. “For the first time, we measured the motion of the gas in every possible direction. Rotating around, moving towards or away from the star, and up or downwards in the disk.”

Teague and his colleagues saw the gas moving from the upper layers towards the middle of the disk at three different locations. “What most likely happens is that a planet in orbit around the star pushes the gas and dust aside, opening a gap,” Teague explained. “The gas above the gap then collapses into it like a waterfall, causing a rotational flow of gas in the disk.”

This is the best evidence to date that there are indeed planets forming around HD 163296. But astronomers cannot say with one hundred percent certainty that planets cause the gas flows. For example, the star’s magnetic field could also cause disturbances in the gas. “Right now, only direct observation of the planets could rule out the other options. But, the patterns of these gas flows are unique, and very likely, only planets can cause them,” said coauthor Jaehan Bae of the Carnegie Institution for Science, who tested this theory with a computer simulation of the disk.

The location of the three predicted planets in this study correspond to the results from last year. Their positions probably are at 87, 140, and 237 AU (An astronomical unit – AU – is the average distance from the Earth to the Sun). The closest planet to HD 163296 is calculated to be half the mass of Jupiter, the middle planet is Jupiter-mass, and the farthest planet is twice as massive as Jupiter.

Gas flows from the surface towards the midplane of the protoplanetary disk have been predicted since the late nineties. But this is the first time that astronomers observed them. Besides being useful to detect infant planets, these flows can also shape our understanding of how gas giant planets obtain their atmospheres.

“Planets form in the middle layer of the disk, the so-called midplane. This is a cold place, shielded from radiation from the star,” Teague explained. “We think that the gaps caused by planets bring in warmer gas from the more chemically active outer layers of the disk and that this gas will form the atmosphere of the planet.”

Teague and his team did not expect that they would be able to see this phenomenon. “The disk around HD 163296 is the brightest and biggest disk we can see with ALMA,” said Teague. “But it was a big surprise to see these gas flows so clearly. The disks appear to be much more dynamic than we thought.”

“This gives us a much more complete picture of planet formation than we ever dreamed,” said coauthor Ted Bergin of the University of Michigan. “By characterizing these flows, we can determine how planets like Jupiter are born and characterize their chemical composition at birth. We might be able to use this to trace the birth location of these planets, as they can move during formation.”

Additional information

This research is presented in a paper by R. Teague et al. in Nature.

See the full article here .

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The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From ALMA: “ALMA Observes Counter-intuitive Flows Around Black Hole”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

From ALMA

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory
, Tokyo – Japan
Phone: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp

Bárbara Ferreira
ESO Public Information Officer
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: pio@eso.org

Iris Nijman
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USA
Cell phone: +1 (434) 249 3423
Email: alma-pr@nrao.edu

Artist impression of the heart of galaxy NGC 1068, which harbors an actively feeding supermassive black hole, hidden within a thick doughnut-shaped cloud of dust and gas. ALMA discovered two counter-rotating flows of gas around the black hole. The colors in this image represent the motion of the gas: blue is material moving toward us, red is moving away. Credit: NRAO/AUI/NSF, S. Dagnello.

ALMA image showing two disks of gas moving in opposite directions around the black hole in galaxy NGC 1068. The colors in this image represent the motion of the gas: blue is material moving toward us, red is moving away. The white triangles are added to show the accelerated gas that is expelled from the inner disk – forming a thick, obscuring cloud around the black hole. Credit: ALMA (ESO/NAOJ/NRAO), V. Impellizzeri; NRAO/AUI/NSF, S. Dagnello.

At the center of a galaxy called NGC 1068, a supermassive black hole hides within a thick doughnut-shaped cloud of dust and gas. When astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to study this cloud in more detail, they made an unexpected discovery that could explain why supermassive black holes grew so rapidly in the early Universe.

“Thanks to the spectacular resolution of ALMA, we measured the movement of gas in the inner orbits around the black hole,” explains Violette Impellizzeri of the National Radio Astronomy Observatory (NRAO), working at ALMA in Chile and lead author on a paper published in The Astrophysical Journal Letters. “Surprisingly, we found two disks of gas rotating in opposite directions.”

Supermassive black holes already existed when the Universe was young, just a billion years after the Big Bang. But how these extreme objects, whose masses are up to billions of times the mass of the Sun, had time to grow so fast, is an outstanding question among astronomers. This new ALMA discovery could provide a clue. “Counter-rotating gas streams are unstable, which means that clouds fall into the black hole faster than they do in a disk with a single rotation direction,” said Impellizzeri. “This could be a way in which a black hole can grow rapidly.”

NGC 1068 (also known as Messier 77) is a spiral galaxy approximately 47 million light-years from Earth in the direction of the constellation Cetus. At its center is an active galactic nucleus, a supermassive black hole that is actively feeding itself from a thin, rotating disk of gas and dust, also known as an accretion disk.

Previous ALMA observations revealed that the black hole is gulping down material and spewing out gas at incredibly high speeds. This gas that gets expelled from the accretion disk likely contributes to hiding the region around the black hole from optical telescopes.

Impellizzeri and her team used ALMA’s superior zoom lens ability to observe the molecular gas around the black hole. Unexpectedly, they found two counter-rotating disks of gas. The inner disk spans 2-4 light-years and follows the rotation of the galaxy, whereas the outer disk (also known as the torus) spans 4-22 light-years and is rotating the opposite way.

“We did not expect to see this, because gas falling into a black hole would normally spin around it in only one direction,” said Impellizzeri. “Something must have disturbed the flow because it is impossible for a part of the disk to start rotating backward all on its own.”

Counter-rotation is not an unusual phenomenon in space. “We see it in galaxies, usually thousands of light-years away from their galactic centers,” explained co-author Jack Gallimore from Bucknell University in Lewisburg, Pennsylvania. “The counter-rotation always results from the collision or interaction between two galaxies. What makes this result remarkable is that we see it on a much smaller scale, tens of light-years instead of thousands from the central black hole.”

The astronomers think that the backward flow in NGC 1068 might be caused by gas clouds that fell out of the host galaxy, or by a small passing galaxy on a counter-rotating orbit captured in the disk.

At the moment, the outer disk appears to be in a stable orbit around the inner disk. “That will change when the outer disk begins to fall onto the inner disk, which may happen after a few orbits or a few hundred thousand years. The rotating streams of gas will collide and become unstable, and the disks will likely collapse in a luminous event as the molecular gas falls into the black hole. Unfortunately, we will not be there to witness the fireworks,” said Gallimore.

Additional Information

The research team was composed by Violette Impellizzeri1,2, Jack F. Gallimore3, Stefi A. Baum4, Moshe Elitzur5, Richard Davies6, Dieter Lutz6, Roberto Maiolino7, Alessandro Marconi8,9, Robert Nikutta10, Christopher P. O’Dea4, and Eleonora Sani11.

1 Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile

2 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA

3 Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837, USA

4 University of Manitoba, Department of Physics and Astronomy, Winnipeg, MB R3T 2N2, Canada

5 Astronomy Department, University of California, Berkeley, CA 94720, USA

6 Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse 1, D-85748 Garching, Germany

7 Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK

8 Dipartimento di Fisica e Astronomia, Universit’a di Firenze, via G. Sansone 1, I-50019, Sesto Fiorentino (Firenze), Italy

9 INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50135, Firenze, Italy

10 National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719, USA

11 European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From ALMA: “Feeding a Baby Star Through a Whirlpool in Space”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

From ALMA

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory
, Tokyo – Japan
Phone: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp

Calum Turner
ESO Assistant Public Information Officer
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: calum.turner@eso.org

Mariya Lyubenova
ESO Outreach Astronomer
Garching bei München, Germany
Phone: +49 89 32 00 61 88
Email: mlyubeno@eso.org

Iris Nijman
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USA
+1 (434) 249 3423
alma-pr@nrao.edu

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) detected a pair of spiral arms in an accretion disk around a baby star. Interestingly, these spiral density enhancements make the disk appear like a “space whirlpool.” The finding supports current theories of accretion disk feeding process, and potentially brings critical insights into the processes of grain growth and settling that are important to planet formation. These results appear in an article in Nature Astronomy led by Chin-Fei Lee at Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, Taiwan).

“Thanks to the resolving power of ALMA, we finally detected a pair of spirals in a young accretion disk around a baby star. These spirals, long predicted in theory, play a crucial role in the transport of angular momentum. Which allows disk material to swirl towards the baby star”, says Lee with excitement. “Our detection of the spirals is an important milestone in understanding the feeding process of baby stars.”

Spirals detected in protoplanetary disks around somewhat older stars seem to be produced by interaction with unseen baby planets. Unlike those, the spirals here are induced by accretion of material from the surrounding molecular cloud onto the disk.

The protostar with its disk lies at the center of HH 111, a pair of supersonic jets emerging from a molecular cloud core located 1300 lightyears away in the constellation Orion. The protostar is about half a million years old, just one ten-thousandth the age of our Sun, and has a mass 50% greater than our Sun. A portion of the flow through the disk onto the budding star is diverted to form the spectacular jets. Previous observations with a resolution of 120 AU (An astronomical unit – AU – is the average distance from the Earth to the Sun) detected the accretion disk orbiting the protostar out to a radius of 160 AU. The new observations with ALMA have a resolution of 16 AU, almost eight times better. With this outstanding capability, astronomers were able to resolve the disk spatially. They detected a pair of spiral arms by the glow of thermal emission from dust particles concentrated there (Figure 1).

The team’s observations open up the exciting possibility of detecting spiral structures in the accretion disks around protostars through high-resolution and high-sensitivity imaging with ALMA, which allows studying accretion disk feeding processes in depth. Such observations also provide insight into accretion disks around other kinds of astrophysical objects, including the supermassive black holes found at the center of active galaxies.

(Top) Optical image of the jet in the HH 111 protostellar system taken by the Hubble Space Telescope (Reipurth et al. 1999). (Bottom left) Accretion disk detected with ALMA in dust continuum emission at 850 micron. (Bottom middle) The disk turned (de-projected) to be face-on, showing a pair of faint spirals. (Bottom right) Annularly averaged continuum emission is subtracted to highlight the faint spirals in the disk. Credit: ALMA (ESO/NAOJ/NRAO)/Lee et al.

The team is composed of Chin-Fei Lee (ASIAA, Taiwan; National Taiwan University, Taiwan), Zhi-Yun Li (University of Virginia, USA), and Neal J. Turner (JPL/Caltech, USA).

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From ALMA: “Rarest form of CO Provides Hint to the Birth of Planets around Young Star”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

From ALMA

Astronomers have discovered the rarest stable carbon monoxide isotope molecule, 13C17O, in the dust and gas disk around a young star using ALMA for the first time. The observations indicate that the disk is more massive than previous estimates, and they may provide an important key to solve mysteries about the planet formation processes in disks.

Images of 13C17O line emission (green), 12C16O line emission (blue), and dust continuum emission (red and blue) Credit; ALMA (ESO/NAOJ/NRAO), University of Leeds

The young star, named HD 163296, is located 330 light-years away in the constellation Sagittarius. It is surrounded by a disk of dust and gas – a so-called protoplanetary disk, in which young planets are forming. This disk has multiple ring and gap patterns which are thought to be sub-structures induced by new-born large planets. (https://alma-telescope.jp/en/news/dsharp-201812)

Using the Atacama Large Millimeter/submillimeter Array (ALMA) in the Atacama Desert, Chile, researchers detected an extremely faint signal showing the existence of 13C17O, a rare carbon monoxide isotopologue, that is to say a molecule containing one or more isotopes.

The detection has allowed scientists to measure the mass of the gas in the disk more accurately than before. The results show that the disk is much heavier – or more ‘massive’ – than previously thought.

An artist’s impression of planets forming in the ring of gas and dust surrounding a star. Credit; ESO/ L. Calçada

Alice Booth, a PhD student in the School of Physics and Astronomy, University of Leeds who led the study [The Astrophysical Journal Letters], said: “Our new observations showed there was between two and six times more mass hiding in the disk than previous observations could measure. This is an important finding in terms of the birth of planetary systems in disks – if they contain more gas, then they have more building material to form more massive planets.”

The research team members are:
Alice S. Booth (University of Leeds), Catherine Walsh (University of Leeds), John D. Ilee (University of Leeds), Shota Notsu (Leiden University/Kyoto University), Chunhua Qi (Harvard-Smithsonian Center for Astrophysics), Hideko Nomura (National Astronomical Observatory of Japan/Tokyo Institute of Technology), Eiji Akiyama (Hokkaido University)

This group’s conclusions are well timed. Recent observations of protoplanetary disks have perplexed astronomers because the disks did not seem to contain enough gas and dust to create the planets observed.

Dr. John Ilee, a researcher at University of Leeds who was also involved in the study, added: “The disk-exoplanet mass discrepancy raises serious questions about how and when planets are formed. However, if other disks are hiding similar amounts of mass as HD 163296, then we may just have underestimated their masses until now.”

Disk gas masses are usually estimated by observing common forms of carbon monoxide (CO). This molecule is the most useful to determine disk gas mass, since it is abundant and is much easier to observe in cold disks than hydrogen molecules. However the fact that CO is abundant can also become a problem. If the disks are sufficiently dense, however, then the outermost CO molecules start to block part of the emissions from CO molecules deeper within the disk – and that could result in scientists underestimating the total mass of the gas.

In this study, the scientists targeted the much rarer 13C17O molecule. Because it is rarer, there is less self-blocking, so that the observers could peer deeper inside the disk and find previously hidden gas.

The scientists expect that using ALMA, they can observe this rare form of CO in many other disks. Dr. Shota Notsu, a JSPS Overseas Research Fellow in Leiden Observatory, Leiden University who was also involved in this study, said: “Measuring the accurate disk masses is key to understand processes of planet formation. Future studies using the rarest forms of CO will enable us to measure the missing mass in many more protoplanetary disks and determine their planet-forming potential.”

See the full article here .

five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From Max Planck Institute for Extraterrestrial Physics: “Food for young twin stars”

From Max Planck Institute for Extraterrestrial Physics

October 03, 2019
Dr. Hannelore Hämmerle
Press Officer Max Planck Institute for Extraterrestrial Physics,
Garching,Germany
+49 89 30000-3980
hannelore.haemmerle@mpe.mpg.de

Dr. Felipe Alves
Max Planck Institute for Extraterrestrial Physics,
Garching, Germany
+49 89 30000-3897
falves@mpe.mpg.de

Stars are born in the midst of large clouds of gas and dust. Local densifications first form “embryos”, which then collect matter and grow. But how exactly does this process, called “accretion”, work? And what happens when two stars form in a disk of matter? High-resolution images of a young stellar binary system for the first time reveal a complex network of accretion filaments nurturing two proto-stars at the centre of the circum-binary disk. With these observations, an international team of astronomers led by the Max Planck Institute for Extraterrestrial Physics was able to identify a two-level accretion process, circum-binary disk to circumstellar disk to stars, constraining the conditions leading to the formation and evolution of binary star systems.

Cosmic delivery room: This picture shows Barnard 59, part of a vast dark cloud of interstellar dust called the Pipe Nebula. The proto-binary systems [BHB2007] 11 studied with high-resolution images is embedded in dense clouds, but can be observed at longer wavelengths with the radio telescope ALMA (Atacama Large Millimeter/submillimeter Array). © ESO

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

Most stars in the universe come in the form of pairs – binaries – or even multiple star systems. Now, the formation of such a binary star system has been observed for the first time with high-resolution ALMA (Atacama Large Millimetre/submillimetre Array) images. An international team of astronomers led by the Max Planck Institute for Extraterrestrial Physics targeted the system [BHB2007] 11, the youngest member of a small cluster of young stellar objects in the Barnard 59 core in the Pipe nebula molecular cloud. While previous observations showed an accretion envelope surrounding a circum-binary disk, the new observations now also reveal its inner structure.

“We see two compact sources, that we interpret as circum-stellar disks around the two young stars,” explains Felipe Alves from MPE, who led the study. “The size of each of these disks is similar to the asteroid belt in our Solar System, and their mutual distance is about 28 times the distance between the Earth and the Sun.” Both proto-stars are surrounded by a circum-binary disk with a total mass of about 80 Jupiter masses, which shows a complex network of dust structures distributed in spiral shapes. The shape of the filaments suggest streamers of in-falling material, which is confirmed by the observation of molecular emission lines.

A zoom into the shared disk: this observation of ALMA shows that the proto-binary system [BHB2007] 11 is surrounded by dust filaments, where the southern (brighter) young star accretes more material. © MPE

“This is a really important result,” stresses Paola Caselli, director and MPE and head of the Centre of Astrochemical Studies. “We have finally imaged the complex structure of young binary stars, with their “feeding filaments” connecting them to the circum-binary disk. This provides important constraints for current models of star formation.”

The astronomers interpret the filaments as inflow streamers from the extended circum-binary disk, where the circum-stellar disk around the less massive of the two proto-stars receives more input, consistent with theoretical predictions. The estimated accretion rate is only about 0.01 Jupiter masses per year, which agrees with rates estimated for other proto-stellar systems. In a similar way as the circum-binary disk feeds the circum-stellar disks, each circum-stellar disk feeds the proto-star in its centre. At the disk-star level though, the accretion rate inferred from the observations is higher for the more massive object. The observation of emission from an extended radio jet for the northern object confirms this result, which is an independent indication that this proto-star is indeed accreting more material.

“We expect this two-level accretion process to drive the dynamics of the binary system during its mass accretion phase,” states Alves. “While the good agreement of these observations with theory is already very promising, we will need to study more young binary systems in detail to further constrain the conditions that lead to stellar multiplicity.”

Original publication:
Gas flow and accretion via spiral streamers and circumstellar disks in a young binary protostar
Science

The team is composed of F. O. Alves (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany), P. Caselli (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Germany), J. M. Girart (Institut de Ciències de l’Espai, Consejo Superior de Investigaciones Científicas, Spain and Institut d’Estudis Espacials de Catalunya, Spain), D. Segura-Cox (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany), G. A. P. Franco (Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Brazil), A. Schmiedeke (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany) and B. Zhao (Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany).

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

For their astrophysical research, the MPE scientists measure the radiation of far away objects in different wavelenths areas: from millimetere/sub-millimetre and infared all the way to X-ray and gamma-ray wavelengths. These methods span more than twelve decades of the electromagnetic spectrum.

The research topics pursued at MPE range from the physics of cosmic plasmas and of stars to the physics and chemistry of interstellar matter, from star formation and nucleosynthesis to extragalactic astrophysics and cosmology. The interaction with observers and experimentalists in the institute not only leads to better consolidated efforts but also helps to identify new, promising research areas early on.

The structural development of the institute mainly has been directed by the desire to work on cutting-edge experimental, astrophysical topics using instruments developed in-house. This includes individual detectors, spectrometers and cameras but also telescopes and integrated, complete payloads. Therefore the engineering and workshop areas are especially important for the close interlink between scientific and technical aspects.

The scientific work is done in four major research areas that are supervised by one of the directors:

Center for Astrochemical Studies (CAS)
Director: P. Caselli

High-Energy Astrophysics
Director: P. Nandra

Infrared/Submillimeter Astronomy
Director: R. Genzel

Optical & Interpretative Astronomy
Director: R. Bender

Within these areas scientists lead individual experiments and research projects organised in about 25 project teams.

The Max Planck Society is Germany’s most successful research organization. Since its establishment in 1948, no fewer than 18 Nobel laureates have emerged from the ranks of its scientists, putting it on a par with the best and most prestigious research institutions worldwide. The more than 15,000 publications each year in internationally renowned scientific journals are proof of the outstanding research work conducted at Max Planck Institutes – and many of those articles are among the most-cited publications in the relevant field.

What is the basis of this success? The scientific attractiveness of the Max Planck Society is based on its understanding of research: Max Planck Institutes are built up solely around the world’s leading researchers. They themselves define their research subjects and are given the best working conditions, as well as free reign in selecting their staff. This is the core of the Harnack principle, which dates back to Adolph von Harnack, the first president of the Kaiser Wilhelm Society, which was established in 1911. This principle has been successfully applied for nearly one hundred years. The Max Planck Society continues the tradition of its predecessor institution with this structural principle of the person-centered research organization.

The currently 83 Max Planck Institutes and facilities conduct basic research in the service of the general public in the natural sciences, life sciences, social sciences, and the humanities. Max Planck Institutes focus on research fields that are particularly innovative, or that are especially demanding in terms of funding or time requirements. And their research spectrum is continually evolving: new institutes are established to find answers to seminal, forward-looking scientific questions, while others are closed when, for example, their research field has been widely established at universities. This continuous renewal preserves the scope the Max Planck Society needs to react quickly to pioneering scientific developments.

From Discover Magazine: “Massive Clouds Colliding in Space Could be Birthing Huge Stars”

From Discover Magazine

September 4, 2019
Mara Johnson-Groh

This star-forming region is one of many in M33 that’s birthing new stars from massive clouds of dust and gas. (Credit: ESA/Hubble and NASA)

Astronomers have witnessed a rare event: the birth of massive stars 2.73 million light-years away in the Triangulum Galaxy (Messier 33). At the center of two giant colliding gas clouds are some 10 young stars with masses tens of times that of the Sun. Their discovery indicates that such cloud-cloud collisions are a main pathway to creating giant stars in the nearby universe, which could help answer the long-standing question of how big stars form.

Cosmic Collision

High-mass stars — those at least eight times the mass of the Sun — are the celebrities of galaxies. Although they’re relatively rare, they produce most of a galaxy’s visible light. They also strongly influence the environment around them through the radiation they release during their lifetimes and the heavy elements they scatter upon their explosive deaths. Their formation, however, remains debated.

New research submitted to the Publications of the Astronomical Society of Japan uses the Atacama Large Millimeter/submillimeter Array to study two giant clouds in Messier 33.

The Triangulum Galaxy, Messier 33, via The VLT Survey Telescope (VST) at ESO’s Paranal Observatory in Chile. This beautifully detailed image of the galaxy Messier 33. This nearby spiral, the second closest large galaxy to our own galaxy, the Milky Way, is packed with bright star clusters, and clouds of gas and dust. This picture is amongst the most detailed wide-field views of this object ever taken and shows the many glowing red gas clouds in the spiral arms with particular clarity.

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

The clouds are 190,000 and 240,000 times more massive than the Sun, respectively, and contain molecules such as molecular hydrogen and carbon dioxide. The two clouds collided at supersonic speeds around 500,000 years ago. (Here, “supersonic” means faster than the speed of sound in the clouds’ environment. In dense regions of space, the speed of sound can be a few miles per second or more; on Earth at sea level, the speed of sound is just over 1,100 feet [340 meters] per second).

The researchers looked specifically for signatures of carbon monoxide, which can be easily seen in radio observations, to chart the denser filamentary structures in the clouds. They also looked for a specific signature of hydrogen that indicates the presence of massive stars. At the center of the collision, they found 10 objects that appear to be young, massive stars. That makes it highly likely that the collision caused changes in the clouds’ gas that made it collapse to form the stars.

Go Big

Massive stars, which are harder to form than smaller stars, aren’t seen everywhere low-mass star formation occurs. So, the question is: Why not?

Astronomers think massive star formation must require some sort of additional triggering mechanism, such as cloud-cloud collisions, strong winds blown off active stars, expanding gas heated by other massive stars or shockwaves sent out by exploding supernovae. But until recently, there was scant observational evidence supporting cloud-cloud collisions. This study, however, now bolsters that option as a way to form massive stars.

“We have a number of different ideas of how massive star formation is initiated,” says Harold Yorke, an astronomer at the NASA Ames Research Center in Mountain View, California. “We know that molecular clouds are turbulent, so you would suspect massive stars could form in those conditions.”

“Recently, there has been a lot of observational, theoretical evidence of the cloud-to-cloud collision as the formation mechanism of massive stars,” says Toshikazu Onishi at the Osaka Prefecture University in Osaka, Japan, and co-author on the new study. “This paper provides the first observational evidence of [cloud-to-cloud collision] for massive star formation in the [Triangulum Galaxy].”

See the full article here .

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From ALMA: “ALMA Shows What’s Inside Jupiter’s Storms”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

From ALMA

22 August, 2019

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Iris Nijman
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USA
Cell phone: +1 (434) 249 3423
Email: alma-pr@nrao.edu

Radio image of Jupiter made with ALMA. Bright bands indicate high temperatures and dark bands low temperatures. The dark bands correspond to the zones on Jupiter, which are often white at visible wavelengths. The bright bands correspond to the brown belts on the planet. This image contains over 10 hours of data, so fine details are smeared by the planet’s rotation. Credit: ALMA (ESO/NAOJ/NRAO), I. de Pater et al.; NRAO/AUI NSF, S. Dagnello

Swirling clouds, big colorful belts, giant storms. The beautiful and incredibly turbulent atmosphere of Jupiter has been showcased many times. But what is going on below the clouds? What is causing the many storms and eruptions that we see on the ‘surface’ of the planet? However, to study this, visible light is not enough. We need to study Jupiter using radio waves.

New radio wave images made with the Atacama Large Millimeter/submillimeter Array (ALMA) provide a unique view of Jupiter’s atmosphere down to fifty kilometers below the planet’s visible (ammonia) cloud deck.

“ALMA enabled us to make a three-dimensional map of the distribution of ammonia gas below the clouds. And for the first time, we were able to study the atmosphere below the ammonia cloud layers after an energetic eruption on Jupiter,” said Imke de Pater of the University of California, Berkeley (EE. UU.).

The atmosphere of giant Jupiter is made out of mostly hydrogen and helium, together with trace gases of methane, ammonia, hydrosulfide, and water. The top-most cloud layer is made up of ammonia ice. Below that is a layer of solid ammonia hydrosulfide particles, and deeper still, around 80 kilometers below the upper cloud deck, there likely is a layer of liquid water. The upper clouds form the distinctive brown belts and white zones seen from Earth.

Many of the storms on Jupiter take place inside those belts. They can be compared to thunderstorms on Earth and are often associated with lightning events. Storms reveal themselves in visible light as small bright clouds, referred to as plumes. These plume eruptions can cause a major disruption of the belt, which can be visible for months or years.

The ALMA images were taken a few days after amateur astronomers observed an eruption in Jupiter’s South Equatorial Belt in January 2017. A small bright white plume was visible first, and then a large-scale disruption in the belt was observed that lasted for weeks after the eruption.

De Pater and her colleagues used ALMA to study the atmosphere below the plume and the disrupted belt at radio wavelengths and compared these to UV-visible light and infrared images made with other telescopes at approximately the same time.

“Our ALMA observations are the first to show that high concentrations of ammonia gas are brought up during an energetic eruption,” said de Pater. “The combination of observations simultaneously at many different wavelengths enabled us to examine the eruption in detail. Wich led us to confirm the current theory that energetic plumes are triggered by moist convection at the base of water clouds, which are located deep in the atmosphere. The plumes bring up ammonia gas from deep in the atmosphere to high altitudes, well above the main ammonia cloud deck,” she added.

“These ALMA maps at millimeter wavelengths complement the maps made with the National Science Foundation’s Very Large Array in centimeter wavelengths,” said Bryan Butler of the National Radio Astronomy Observatory.

NRAO/Karl V Jansky Expanded Very Large Array, on the Plains of San Agustin fifty miles west of Socorro, NM, USA, at an elevation of 6970 ft (2124 m)

“Both maps probe below the cloud layers seen at optical wavelengths and show ammonia-rich gases rising into and forming the upper cloud layers (zones), and ammonia-poor air sinking down (belts).”

“The present results show superbly what can be achieved in planetary science when an object is studied with various observatories and at various wavelengths”. Explains Eric Villard, an ALMA astronomer part of the research team. “ALMA, with its unprecedented sensitivity and spectral resolution at radio wavelengths, worked together successfully with other major observatories around the world, to provide the data to allow a better understanding of the atmosphere of Jupiter.”

Flat map of Jupiter in radio waves with ALMA (top) and visible light with the Hubble Space Telescope (bottom). The eruption in the South Equatorial Belt is visible in both images. Credit: ALMA (ESO/NAOJ/NRAO), I. de Pater et al.; NRAO/AUI NSF, S. Dagnello; NASA/Hubble

Science paper:
First ALMA Millimeter Wavelength Maps of Jupiter, with a Multi-Wavelength Study of Convection
https://arxiv.org/pdf/1907.11820.pdf

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From ALMA: “ALMA Identified Dark Ancestors of Massive Elliptical Galaxies”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

From ALMA

7 August, 2019

Tao Wang
Postdoctoral fellow
Institute of Astronomy, The University of Tokyo / National Astronomical Observatory of Japan
Email: taowang@ioa.s.u-tokyo.ac.jp

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory
, Tokyo – Japan
Phone: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp

Calum Turner
ESO Assistant Public Information Officer
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: calum.turner@eso.org

Mariya Lyubenova
ESO Outreach Astronomer
Garching bei München, Germany
Phone: +49 89 32 00 61 88
Email: mlyubeno@eso.org

Iris Nijman
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USA
Cell phone: +1 (434) 249 3423
Email: alma-pr@nrao.edu

An artistic representation of the distant galaxies observed with ALMA. ALMA identified faint galaxies invisible to the Hubble Space Telescope. For the research team, these galaxies precede the massive elliptical galaxies of the present Universe. Credits: NAOJ

Astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to identify 39 faint galaxies that are not seen with the Hubble Space Telescope’s most in-depth view of the Universe, 10 billion light-years away. They are ten times more numerous than similarly massive but optically–bright galaxies detected with Hubble. The research team assumes that these faint galaxies precede massive elliptical galaxies in the present Universe. However, no significant theories for the evolution of the Universe have predicted such an abundant population of star-forming, dark, massive galaxies. The new ALMA results throw into question our understanding of the early Universe. These results appear in the latest issue of the journal Nature.

“Previous studies have found extremely active star-forming galaxies in the early Universe, but their population is quite limited,” says Tao Wang, lead author of this research at the University of Tokyo, the French Alternative Energies and Atomic Energy Commission (CEA), and the National Astronomical Observatory of Japan (NAOJ). “Star formation in the dark galaxies we identified is less intense, but they are 100 times more abundant than the extreme starbursts. It is important to study such a major component of the history of the Universe to comprehend galaxy formation.”

Wang and his team targeted three ALMA windows to the deep Universe opened up by the Hubble Space Telescope (HST): the CANDELS fields. The team discovered 63 extremely red objects in the infrared images taken by NASA’s Spitzer Space Telescope: they are too red to be detected with HST. However, Spitzer’s limited spatial resolution prevented astronomers from identifying their nature.

ALMA detected submillimeter-wave emission from 39 out of the 63 extremely red objects. Thanks to its high resolution and sensitivity, ALMA confirmed that they are massive, star-forming galaxies that are producing stars 100 times more efficiently than the Milky Way. These galaxies are representative of the majority of massive galaxies in the Universe 10 billion years ago, most of which have so far been missed by previous studies.

“By maintaining this rate of star formation, these ALMA-detected galaxies will likely transform into the first population of massive elliptical galaxies formed in the early Universe,” says David Elbaz, an astronomer at CEA, and coauthor on the paper, “But there is a problem. They are unexpectedly abundant.” The researchers estimated their number density to be equivalent to 530 objects in a square degree in the sky. This number density well exceeds predictions from current theoretical models and computer simulations. Also, according to the widely accepted model of the Universe with a particular type of dark matter, it is challenging to build a large number of massive objects in such an early phase of the Universe. Together, the present ALMA results challenge our current understanding of the evolution of the Universe.

“Like the galaxy Messier 87, from which astronomers recently obtained the first-ever image of a black hole, massive elliptical galaxies are located in the heart of galaxy clusters.

The first image of a black hole, Messier 87 Credit Event Horizon Telescope Collaboration, via NSF and ERC 4.10.19

Katie Bouman of Harvard Smithsonian Observatory for Astrophysics, headed to Caltech, with EHT hard drives from Messier 87

Scientist believes that these galaxies formed most of their stars in the early Universe,” explains Kotaro Kohno, a professor at the University of Tokyo and member of the research team. “However, previous searches for the progenitors of these massive galaxies have been unsuccessful because they were based solely on galaxies that are easily detectable by HST. The discovery of this large number of massive, HST-dark galaxies provides direct evidence for the early assembly of massive galaxies during the first billion years of the Universe.” More detailed follow-up observations with ALMA and NASA’s James Webb Space Telescope are essential to provide further insights into the nature of these galaxies. New studies could enable a complete view of galaxy formation in the early Universe.”

ALMA identified 39 faint galaxies that are not seen with the Hubble Space Telescope’s most in-depth view of the Universe 10 billion light-years away. This example image shows a comparison of Hubble and ALMA observations. The squares numbered from 1 to 4 are the locations of faint galaxies unseen in the Hubble image. Credit: The University of Tokyo/CEA/NAOJ.

The research team members are:
T. Wang (The University of Tokyo/CEA/National Astronomical Observatory of Japan), C. Schreiber (CEA/Leiden University/Oxford University), D. Elbaz (CEA), Y. Yoshimura (The University of Tokyo), K. Kohno (The University of Tokyo), X. Shu (Anhui Normal University), Y. Yamaguchi (The University of Tokyo), M. Pannella (Ludwig-Maximilians-Universitat,), M. Franco (CEA), J. Huang (National Astronomical Observatories of China), C.-F. Lim (Academia Sinica Institute of Astronomy and Astrophysics), and W.-H. Wang (Academia Sinica Institute of Astronomy and Astrophysics).

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From ALMA via NRAO: “ALMA Dives into Black Hole’s ‘Sphere of Influence’”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

From ALMA

via

National Radio Astronomy Observatory

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory
, Tokyo – Japan
Phone: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp

Calum Turner
ESO Assistant Public Information Officer
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: calum.turner@eso.org

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USA
Phone: +1 434 296 0314
Cell phone: +1 202 236 6324
Email: cblue@nrao.edu

Credit: ALMA (ESO/NAOJ/NRAO), B. Boizelle; NRAO/AUI/NSF, S. Dagnello; Hubble Space Telescope (NASA/ESA); Carnegie-Irvine Galaxy Survey

ALMA has made the most precise measurements of cold gas swirling around a supermassive black hole — the cosmic behemoth at the center of the giant elliptical galaxy NGC 3258. The multi-color ellipse reflects the motion of the gas orbiting the black hole, with blue indicating motion toward us and red motion away from us. The inset box represents how the orbital velocity changes with distance from the black hole. The material was found to rotate faster the closer in the astronomers observed to the black hole, enabling them to accurately calculate its mass: a whopping 2.25 billion times the mass of our Sun.

What happens inside a black hole stays inside a black hole, but what happens inside a black hole’s “sphere of influence” – the innermost region of a galaxy where a black hole’s gravity is the dominant force – is of intense interest to astronomers and can help determine the mass of a black hole as well as its impact on its galactic neighborhood.

New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) provide an unprecedented close-up view of a swirling disk of cold interstellar gas rotating around a supermassive black hole. This disk lies at the center of NGC 3258, a massive elliptical galaxy about 100 million light-years from Earth. Based on these observations, a team led by astronomers from Texas A&M University and the University of California, Irvine, have determined that this black hole weighs a staggering 2.25 billion solar masses, the most massive black hole measured with ALMA to date.

Though supermassive black holes can have masses that are millions to billions of times that of the Sun, they account for just a small fraction of the mass of an entire galaxy. Isolating the influence of a black hole’s gravity from the stars, interstellar gas, and dark matter in the galactic center is challenging and requires highly sensitive observations on phenomenally small scales.

“Observing the orbital motion of material as close as possible to a black hole is vitally important when accurately determining the black hole’s mass.” said Benjamin Boizelle, a postdoctoral researcher at Texas A&M University and lead author on the study appearing in The Astrophysical Journal. “These new observations of NGC 3258 demonstrate ALMA’s amazing power to map the rotation of gaseous disks around supermassive black holes in stunning detail.”

Astronomers use a variety of methods to measure black hole masses. In giant elliptical galaxies, most measurements come from observations of the orbital motion of stars around the black hole, taken in visible or infrared light. Another technique, using naturally occurring water masers (radio-wavelength lasers) in gas clouds orbiting around black holes, provides higher precision, but these masers are very rare and are associated almost exclusively with spiral galaxies having smaller black holes.

During the past few years, ALMA has pioneered a new method to study black holes in giant elliptical galaxies. About 10 percent of elliptical galaxies contain regularly rotating disks of cold, dense gas at their centers. These disks contain carbon monoxide (CO) gas, which can be observed with millimeter-wavelength radio telescopes.

By using the Doppler shift of the emission from CO molecules, astronomers can measure the velocities of orbiting gas clouds, and ALMA makes it possible to resolve the very centers of galaxies where the orbital speeds are highest.

“Our team has been surveying nearby elliptical galaxies with ALMA for several years to find and study disks of molecular gas rotating around giant black holes,” said Aaron Barth of UC Irvine, a co-author on the study. “NGC 3258 is the best target we’ve found, because we’re able to trace the disk’s rotation closer to the black hole than in any other galaxy.”

Just as the Earth orbits around the Sun faster than Pluto does because it experiences a stronger gravitational force, the inner regions of the NGC 3258 disk orbit faster than the outer parts due to the black hole’s gravity. The ALMA data show that the disk’s rotation speed rises from 1 million kilometers per hour at its outer edge, about 500 light-years from the black hole, to well over 3 million kilometers per hour near the disk’s center at a distance of just 65 light-years from the black hole.

The researchers determined the black hole’s mass by modeling the disk’s rotation, accounting for the additional mass of the stars in the galaxy’s central region and other details such as the slightly warped shape of the gaseous disk. The clear detection of rapid rotation enabled the researchers to determine the black hole’s mass with a precision better than one percent, although they estimate an additional systematic 12 percent uncertainty in the measurement because the distance to NGC 3258 is not known very precisely. Even accounting for the uncertain distance, this is one of the most highly precise mass measurements for any black hole outside of the Milky Way galaxy.

“The next challenge is to find more examples of near-perfect rotating disks like this one so that we can apply this method to measure black hole masses in a larger sample of galaxies,” concluded Boizelle. “Additional ALMA observations that reach this level of precision will help us better understand the growth of both galaxies and black holes across the age of the universe.”

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

From ALMA: “‘Moon Forming’ Circumplanetary Disk Discovered around Young Planet in Distant Star System”

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

From ALMA

11 July, 2019

Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory
, Tokyo – Japan
Phone: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp

Mariya Lyubenova
ESO Outreach Astronomer
Garching bei München, Germany
Phone: +49 89 32 00 61 88
Email: mlyubeno@eso.org

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USA
Phone: +1 434 296 0314
Cell phone: +1 202 236 6324
Email: cblue@nrao.edu

ALMA image of the dust in PDS 70, a star system located approximately 370 light-years from Earth. Two faint smudges in the gap region of this disk are associated with newly formed planets. One such concentration of dust is a circumplanetary disk, the first such feature ever detected around a distant star. Credit: ALMA (ESO/NAOJ/NRAO); A. Isella.

Composite image of PDS 70. Comparing new ALMA data to earlier VLT observations, astronomers determined that the young planet designated PDS 70 c has a circumplanetary disk, a feature that is strongly theorized to be the birthplace of moons. Credit: ALMA (ESO/NOAJ/NRAO) A. Isella; ESO.

ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
•KUEYEN (UT2; The Moon ),
•MELIPAL (UT3; The Southern Cross ), and
•YEPUN (UT4; Venus – as evening star).
elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

ESO SPHERE extreme adaptive optics system and coronagraphic facility on the extreme adaptive optics system and coronagraphic facility on the VLT MELIPAL UT3, Cerro Paranal, Chile, with an elevation of 2,635 metres (8,645 ft) above sea level

ESO MUSE on the VLT on Yepun (UT4)

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made the first-ever observations of a circumplanetary disk, the planet-girding belt of dust and gas that astronomers strongly theorize controls the formation of planets and gives rise to an entire system of moons, like the one found around Jupiter.

This young star system, PDS 70, is located approximately 370 light-years from Earth. Recently, astronomers confirmed the presence of two massive, Jupiter-like planets in orbit around the star. This discovery was made with the European Southern Observatory’s Very Large Telescope (VLT), which detected the warm glow naturally emitted by hydrogen gas accreting onto the planets.

The new ALMA observations instead image the faint radio waves given off by the tiny (about one tenth of a millimeter across) particles of dust around the star.

The ALMA data, combined with the earlier optical and infrared VLT observations, provide compelling evidence that a dusty disk capable of forming multiple moons surrounds the outermost known planet in the system.

“For the first time, we can conclusively see the telltale signs of a circumplanetary disk, which helps to support many of the current theories of planet formation,” said Andrea Isella, an astronomer at Rice University in Houston, Texas, and lead author on a paper published in The Astrophysical Journal Letters.

“By comparing our observations to the high-resolution infrared and optical images, we can see that an otherwise enigmatic concentration of tiny dust particles is a planet-girding disk of dust, the first such feature ever conclusively observed,” he said. According to the researchers, this is the first time that a planet has been seen in these three distinct bands of light (optical, infrared, and radio).

Unlike the icy rings of Saturn, which likely formed by the crashing together of comets and rocky bodies relatively recently in the history of our Solar System, a circumplanetary disk is the lingering remains of the planet-formation process.

The ALMA data also revealed two distinct differences between the two newly discovered planets. The closer in of the two, PDS 70 b, which is about the same distance from its star as Uranus is from the Sun, has a trailing mass of dust behind it resembling a tail. “What this is and what it means for this planetary system is not yet known,” said Isella. “The only conclusive thing we can say is that it is far enough from the planet to be an independent feature.”

The second planet, PDS 70 c, resides in the same location as a clear knot of dust seen in the ALMA data. Since this planet is shining so brightly in the infrared and hydrogen bands of light, the astronomers can convincingly say that a fully formed planet is already in orbit there and that nearby gas continues to be siphoned onto the planet’s surface, finishing its adolescent growth spurt.

This outer planet is located approximately 5.3 billion kilometers from the host star, about the same distance as Neptune from our Sun. Astronomers estimate that this planet is approximately 1 to 10 times the mass of Jupiter. “If the planet is on the larger end of that estimate, it’s quite possible there might be planet-size moons forming around it,” noted Isella.

The ALMA observations also add another important element to these observations.

Optical studies of planetary systems are notoriously challenging. Since the star is so much brighter than the planets, it is difficult to filter out the glare, much like trying to spot a firefly next to a searchlight. ALMA observations, however, don’t have that limitation since stars emit comparatively little light at millimeter and submillimeter wavelengths.

“This means we’ll be able to come back to this system at different periods and more easily map the orbit of the planets and the concentration of dust in the system,” concluded Isella. “This will give us unique insights into the orbital properties of solar systems in their very earliest stages of development.”

See the full article here .

five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.