From ALMA: “Liberal Sprinkling of Salt Discovered around a Young Star”

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

From ALMA

7 February, 2019

Valeria Foncea
Education and Public Outreach Officer
Joint ALMA Observatory Santiago – Chile
Phone: +56 2 2467 6258
Cell phone: +56 9 7587 1963
Email: valeria.foncea@alma.cl

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

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

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

Artist impression of Orion Source I, a young, massive star about 1,500 light-years away. New ALMA observations detected a ring of salt — sodium chloride, ordinary table salt — surrounding the star. This is the first detection of salts of any kind associated with a young star. The blue region (about 1/3 the way out from the center of the disk) represents the region where ALMA detected the millimeter-wavelength “glow” from the salts. Credit: NRAO/AUI/NSF; S. Dagnello

ALMA image of the salty disk surrounding the young, massive star Orion Source I (blue ring). It is shown in relation to the Orion Molecular Cloud 1, a region of explosive starbirth. The background near infrared image was taken with the Gemini Observatory. Credit: ALMA (NRAO/ESO/NAOJ); NRAO/AUI/NSF; Gemini Observatory/AURA

Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile, at an altitude of 7200 feet

A team of astronomers and chemists using the Atacama Large Millimeter/submillimeter Array (ALMA) has detected the chemical fingerprints of sodium chloride (NaCl) and other similar salty compounds emanating from the dusty disk surrounding Orion Source I, a massive, young star in a dusty cloud behind the Orion Nebula.

“It’s amazing we’re seeing these molecules at all,” said Adam Ginsburg, a Jansky Fellow of the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, and lead author of a paper accepted for publication in The Astrophysical Journal. “Since we’ve only ever seen these compounds in the sloughed-off outer layers of dying stars, we don’t fully know what our new discovery means. The nature of the detection, however, shows that the environment around this star is very unusual.”

To detect molecules in space, astronomers use radio telescopes to search for their chemical signatures – telltale spikes in the spread-out spectra of radio and millimeter-wavelength light. Atoms and molecules emit these signals in several ways, depending on the temperature of their environments.

The new ALMA observations contain a bristling array of spectral signatures – or transitions, as astronomers refer to them – of the same molecules. To create such strong and varied molecular fingerprints, the temperature differences where the molecules reside must be extreme, ranging anywhere from 100 kelvin to 4,000 kelvin (about -175 Celsius to 3700 Celsius). An in-depth study of these spectral spikes could provide insights about how the star is heating the disk, which would also be a useful measure of the luminosity of the star.

“When we look at the information ALMA has provided, we see about 60 different transitions – or unique fingerprints – of molecules like sodium chloride and potassium chloride coming from the disk. That is both shocking and exciting,” said Brett McGuire, a chemist at the NRAO in Charlottesville, Virginia, and co-author on the paper.

The researchers speculate that these salts come from dust grains that collided and spilled their contents into the surrounding disk. Their observations confirm that the salty regions trace the location of the circumstellar disk.

“Usually when we study protostars in this manner, the signals from the disk and the outflow from the star get muddled, making it difficult to distinguish one from the other,” said Ginsburg. “Since we can now isolate just the disk, we can learn how it is moving and how much mass it contains. It also may tell us new things about the star.”

The detection of salts around a young star is also of interest to astronomers and astrochemists because some of constituent atoms of salts are metals – sodium and potassium. This suggests there may be other metal-containing molecules in this environment. If so, it may be possible to use similar observations to measure the amount of metals in star-forming regions. “This type of study is not available to us at all presently. Free-floating metallic compounds are generally invisible to radio astronomy,” noted McGuire.

The salty signatures were found about 30 to 60 astronomical units (AU, or the average distance between the Earth and the Sun) from the host stars. Based on their observations, the astronomers infer that there may be as much as one sextillion (a one with 21 zeros after it) kilograms of salt in this region, which is roughly equivalent to the entire mass of Earth’s oceans.

“Our next step in this research is to look for salts and metallic molecules in other regions. This will help us understand if these chemical fingerprints are a powerful tool to study a wide range of protoplanetary disks, or if this detection is unique to this source,” said Ginsburg. “In looking to the future, the planned Next Generation VLA would have the right mix of sensitivity and wavelength coverage to study these molecules and perhaps use them as tracers for planet-forming disks.”

Orion Source I formed in the Orion Molecular Cloud I, a region of explosive starbirth previously observed with ALMA. “This star was ejected from its parent cloud with a speed of about 10 kilometers per second around 550 years ago,”1 said John Bally, an astronomer at the University of Colorado and co-author on the paper. “It is possible that solid grains of salt were vaporized by shock waves as the star and its disk were abruptly accelerated by a close encounter or collision with another star. It remains to be seen if salt vapor is present in all disks surrounding massive protostars, or if such vapor traces violent events like the one we observed with ALMA.”

1. Light from this object took about 1,500 years to reach Earth. Astronomers are seeing it as if looking through that window of time, which reveals how it looked 550 years after it was ejected from its stellar nursery.

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.

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From ALMA: “Retreating Snow Line Reveals Organic Molecules around Young Star”

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

From ALMA

4 February, 2019

Valeria Foncea
Education and Public Outreach Officer
Joint ALMA Observatory Santiago – Chile
Phone: +56 2 2467 6258
Cell phone: +56 9 7587 1963
Email: valeria.foncea@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

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

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

False-color image of V883 Ori taken with ALMA. The distribution of dust is shown in orange and the distribution of methanol, an organic molecule, is shown in blue. Credit: ALMA (ESO/NAOJ/NRAO), Lee et al.

Artist’s impression of the protoplanetary disk around a young star V883 Ori. The outer part of the disk is cold and dust particles are covered with ice. ALMA detected various complex organic molecules around the snow line of water in the disk. Credit: National Astronomical Observatory of Japan.

Schematic illustration of the composition of protoplanetary disks in normal state and outburst phase. V883 Ori is experiencing an FU Orionis outburst and the increase in disk temperature pushes the snow line outward, causing various molecules contained in ice to be released into gas. Credit: National Astronomical Observatory of Japan.

Astronomers using ALMA have detected various complex organic molecules around the young star V883 Ori. A sudden outburst from this star is releasing molecules from the icy compounds in the planet forming disk. The chemical composition of the disk is similar to that of comets in the modern Solar System. Sensitive ALMA observations enable astronomers to reconstruct the evolution of organic molecules from the birth of the Solar System to the objects we see today.

The research team led by Jeong-Eun Lee (Kyung Hee University, Korea) used the Atacama Large Millimeter/submillimeter Array (ALMA) to detect complex organic molecules including methanol (CH3OH), acetone (CH3COCH3), acetaldehyde (CH3CHO), methyl formate (CH3OCHO), and acetonitrile (CH3CN). This is the first time that acetone was unambiguously detected in a planet forming region or protoplanetary disk.

Various molecules are frozen in ice around micrometer-sized dust particles in protoplanetary disks. V883 Ori’s sudden flare-up is heating the disk and sublimating the ice, which releases the molecules into gas. The region in a disk where the temperature reaches the sublimation temperature of the molecules is called the “snow line.” The radii of snow lines are about a few astronomical units (au) around normal young stars, however, they are enlarged almost 10 times around bursting stars.

“It is difficult to image a disk on the scale of a few au with current telescopes,” said Lee. “However, around an outburst star, ice melts in a wider area of the disk and it is easier to see the distribution of molecules. We are interested in the distribution of complex organic molecules as the building blocks of life.”

Ice, including frozen organic molecules, could be closely related to the origin of life on planets. In our Solar System, comets are the focus of attention because of their rich icy compounds. For example, the European Space Agency’s legendary comet explorer Rosetta found rich organic chemistry around the comet Churyumov-Gerasimenko.

ESA/Rosetta spacecraft, European Space Agency’s legendary comet explorer Rosetta

Comets are thought to have been formed in the outer colder region of the proto-Solar System, where the molecules were contained in ice. Probing the chemical composition of ice in protoplanetary disks is directly related to probing the origin of organic molecules in comets, and the origin of the building blocks of life.

Comets are thought to have been formed in the outer colder region of the proto-Solar System, where the molecules were contained in ice. Probing the chemical composition of ice in protoplanetary disks is directly related to probing the origin of organic molecules in comets, and the origin of the building blocks of life.

Thanks to ALMA’s sharp vision and the enlarged snow line due to the flare-up of the star, the astronomers obtained the spatial distribution of methanol and acetaldehyde. The distribution of these molecules has a ring-like structure with a radius of 60 au, which is twice the size of Neptune’s orbit. The researchers assume that inside of this ring the molecules are invisible because they are obscured by thick dusty material, and are invisible outside of this radius because they are frozen in ice.

“Since rocky and icy planets are made from solid material, the chemical composition of solids in disks is of special importance. An outburst is a unique chance to investigate fresh sublimates, and thus the composition of solids.” says Yuri Aikawa at the University of Tokyo, a member of the research team.

V883 Ori is a young star located at 1300 light-years away from the Earth. This star is experiencing a so-called FU Orionis type outburst, a sudden increase of luminosity due to a bursting torrent of material flowing from the disk to the star. These outbursts last only on the order of 100 years, therefore the chance to observe a burst is rather rare. However, since young stars with a wide range of ages experience FU Ori bursts, astronomers expect to be able to trace the chemical composition of ice throughout the evolution of young stars.

Note: Another ALMA observation (The Astrophysical Journal Letters) also detected CH3OH emissions from V883 Ori. However, the sensitivity and resolution of the observations were not enough to resolve the structure inside the water snow line.

These observation results are published as Lee et al. “The ice composition in the disk around V883 Ori revealed by its stellar outburst” in Nature Astronomy on February 4, 2019.

The research team members are:

Jeong-Eun Lee (Kyung Hee University), Seokho Lee (Kyung Hee University), Giseon Baek (Kyung Hee University), Yuri Aikawa (The University of Tokyo), Lucas Cieza (Universidad Diego Prtales), Sung-Yong Yoon (Kyung Hee University), Gregory Herczeg (Peking University), Doug Johnstone (NRC Herzberg Astronomy and Astrophysics), Simon Casassus (Universidad de Chile)

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (grant No. NRF-2018R1A2B6003423), the Korea Astronomy and Space Science Institute under the R&D program supervised by the Ministry of Science, ICT and Future Planning, JSPS KAKENHI (No. 16K13782 and 18H05222), the general grant (No. 11473005) by the National Science Foundation of China, National Research Council of Canada, and NSERC Discovery Grant.

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: “Tale As Old As Time”

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

From ALMA

via

National Radio Astronomy Observatory

January 7, 2019

Hot spots in the cosmic microwave background tell us about the history and evolution of distant quasars.

Credit: NRAO/AUI/NSF

Image author of a quasar. Credit: NRAO / AUI / NSF.

Synopsis: Using data from ALMA, a team of astronomers studied the growth and evolution of bubbles of hot plasma produced by active quasar HE 0515-4414. The bubble was analyzed by observing its effect on light from the cosmic microwave background. It is the first time this method has been used to directly study outflows from quasars.

Cosmic microwave background radiation is the first light in the cosmos.

Cosmic microwave background radiation. Stephen Hawking Center for Theoretical Cosmology U Cambridge

The light we see began its journey when the universe was just 380,000 years old, when the temperature of the universe had finally dropped to the point where the primordial plasma of electrons and protons cooled enough to form transparent hydrogen gas. At first, the cosmic background was a nearly perfect blackbody spectrum. A blackbody spectrum is the spectrum of light caused by the temperature of an object. Sunlight, for example, is also a blackbody spectrum. Shortly after it first appeared, the cosmic blackbody was an orange glow, but during its 13.7 billion year journey the expansion of the universe shifted it to infrared and then microwave radiation. We now see this background as a faint glow of microwave light coming from all directions.

CMB per ESA/Planck

ESA/Planck 2009 to 2013

The cosmic background is still a blackbody, but not a perfect one. There are small fluctuations in the background. Regions that are a bit warmer than average, and regions that are slightly cooler. Most of these fluctuations are due to variations in the early universe. Slightly warmer regions expanded to fill the vast voids between galaxies, while slightly cooler regions condensed into galaxies and clusters of galaxies.

But some of these fluctuations are due to the tremendously long journey the light took to reach us. While traveling for billions of years, the light of the cosmic background passed through all the gas, dust and plasma between us and its source. Some of the light was absorbed. Some lost energy by scattering and now appears cooler than it would otherwise. But some of it gained energy, making the cosmic background appear warmer than it should.

This warming process is known as the Sunyaev–Zel’dovich effect (or SZ effect). When low energy photons from the cosmic microwave background pass through a region of hot plasma, they can collide with fast-moving electrons. The photons are then scattered with a great deal of energy. So the cosmic light leaves the region warmer and brighter – leaving a “hole” in the background at low frequencies, corresponding to lower photon energies. By looking for temperature fluctuations in the cosmic background, astronomers can study regions of hot plasma.

In a recent paper published in the Monthly Notices of the Royal Astronomical Society, a team of researchers used the SZ effect to study bubbles of hot plasma near distant quasars. Quasars are bright radio beacons in the sky. They are powered by supermassive black holes in the hearts of galaxies. As the black holes consume matter near them, they radiate tremendous energy. They are often more than 100 times brighter than the galaxy in which they live. This can create a quasar wind of ionized gas that streams away from the galaxy, similar to the way our Sun creates a solar wind. When the quasar wind collides with the diffuse and cool gas of intergalactic space, it can create bubbles of hot plasma.

Quasars aren’t as distant as the cosmic microwave background, but they are still billions of light-years away. That means any light given off by the plasma bubbles is much too faint to be observed directly. But they can be studied through the SZ effect. In order to do that, however, you need to capture high-resolution images of the microwave background. This is where the Atacama Large Millimeter/submillimeter Array (ALMA) comes in. Located high in the Andes of northern Chile, ALMA can capture microwave images at a resolution similar to visible light images captured by the Hubble space telescope. Just as the Hubble can show us beautiful images of distant nebulae, ALMA can capture images of hot plasma bubbles.

Using data from ALMA, the astronomers detected a bubble near the quasar HE 0515-4414. This is a hyperluminous quasar, meaning that it is extremely bright and active. But surprisingly when they used their data to measure the quasar wind, they found it was smaller than anticipated. The quasar wind is only 0.01% of the total luminosity of the quasar. Theoretical models predicted that the quasar wind should be much stronger. It seems that while quasars can create hot bubbles of plasma around a galaxy, the process isn’t particularly efficient.

The scale of the bubble also told them it formed over a period of about 100 million years, and it will take about 600 million years to cool down. Those time scales are long enough that hot plasma bubbles could interact with cooler material in the galaxy to influence star production and the evolution of the galaxy.

Of course this is just the first hot plasma bubble to be observed, and it’s impossible to know if HE 0515-4414 is typical or a rare exception. So the search is on to find more bubble-blowing quasars.

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 Harvard-Smithsonian Center for Astrophysics and U Warwick: “Double Star System Flips Planet-Forming Disk into Pole Position”

From Harvard-Smithsonian Center for Astrophysics

U Warwick

January 14, 2019

Tyler Jump
Public Affairs
Center for Astrophysics | Harvard & Smithsonian
+1 617-495-7462
tyler.jump@cfa.harvard.edu

Peter Thorley
Media Relations Manager (Warwick Medical School and Department of Physics)
Email: peter.thorley@warwick.ac.uk
Tel: +44 (0)24 761 50868
Mob: +44 (0) 7824 540863

New research that included astronomers Luca Matra and David J. Wilner of the Center for Astrophysics | Harvard & Smithsonian has found the first confirmed example of a double star system that has flipped its surrounding disc to a position that leaps over the orbital plane of those stars. The international team of astronomers used the Atacama Large Millimeter/sub-millimeter Array (ALMA) to obtain high-resolution images of the Asteroid belt-sized disc.

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

The overall system presents the unusual sight of a thick hoop of gas and dust circling at right angles to the binary star orbit. Until now this setup only existed in theorists’ minds, but the ALMA observation proves that polar discs of this type exist, and may even be relatively common.

The new research is published today (14 January 2019) by Royal Society University Research Fellow Dr. Grant M. Kennedy of the University of Warwick’s Department of Physics and Centre for Exoplanets and Habitability in Nature Astronomy in a paper entitled “A circumbinary protoplanetary disc in a polar configuration.”

Dr. Grant M. Kennedy of the University of Warwick said:

Discs rich in gas and dust are seen around nearly all young stars, and we know that at least a third of the ones orbiting single stars form planets. Some of these planets end up being misaligned with the spin of the star, so we’ve been wondering whether a similar thing might be possible for circumbinary planets. A quirk of the dynamics means that a so-called polar misalignment should be possible, but until now we had no evidence of misaligned discs in which these planets might form.

Dr. Kennedy and his fellow researchers used ALMA to pin down the orientation of the ring of gas and dust in the system. The orbit of the binary was previously known, from observations that quantified how the stars move in relation to each other. By combining these two pieces of information they were able to establish that the dust ring was consistent with a perfectly polar orbit. This means that while the stellar orbits orbit each other in one plane, like two horses going around on a carousel, the disc surrounds these stars at right angles to their orbits, like a giant ferris wheel with the carousel at the centre.

Dr. Grant M. Kennedy of the University of Warwick added:

Perhaps the most exciting thing about this discovery is that the disc shows some of the same signatures that we attribute to dust growth in discs around single stars. We take this to mean planet formation can at least get started in these polar circumbinary discs. If the rest of the planet formation process can happen, there might be a whole population of misaligned circumbinary planets that we have yet to discover, and things like weird seasonal variations to consider.

If there were a planet or planetoid present at the inner edge of the dust ring, the ring itself would appear from the surface as a broad band rising almost perpendicularly from the horizon. The polar configuration means that the stars would appear to move in and out of the disc plane, giving objects two shadows at times. Seasons on planets in such systems would also be different. On Earth they vary throughout the year as we orbit the Sun. A polar circumbinary planet would have seasons that also vary as different latitudes receive more or less illumination throughout the binary orbit.

The full research team for this paper also included: Dr. Grant M. Kennedy of the University of Warwick’s Department of Physics and Centre for Exoplanets and Habitability as lead author and; Stefano Facchini of the Max-Planck-Institut fur Extraterrestrische Physik; Julien Milli of the European Southern Observatory (ESO); Olja Panic of the School of Physics & Astronomy, University of Leeds; Daniel Price of Monash University’s Centre for Astrophysics (MoCA) and School of Physics and Astronomy; and Mark C. Wyatt, and Ben M. Yelverton of the Institute of Astronomy, University of Cambridge. This press release was first prepared by the University of Warwick.

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory (SAO) is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory (HCO), founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

From ALMA: “What 100,000 Star Factories in 74 Galaxies Tell Us about Star Formation across the Universe”

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

From ALMA

9 January, 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

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

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

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

Galaxies come in a wide variety of shapes and sizes. Some of the most significant differences among galaxies, however, relate to where and how they form new stars. Compelling research to explain these differences has been elusive, but that is about to change. The Atacama Large Millimeter/submillimeter Array (ALMA) is conducting an unprecedented survey of nearby disk galaxies to study their stellar nurseries. With it, astronomers are beginning to unravel the complex and as-yet poorly understood relationship between star-forming clouds and their host galaxies.

A vast, new research project with ALMA, known as PHANGS-ALMA (Physics at High Angular Resolution in Nearby GalaxieS), delves into this question with far greater power and precision than ever before by measuring the demographics and characteristics of a staggering 100,000 individual stellar nurseries spread throughout 74 galaxies.

PHANGS-ALMA, an unprecedented and ongoing research campaign, has already amassed a total of 750 hours of observations and given astronomers a much clearer understanding of how the cycle of star formation changes, depending on the size, age, and internal dynamics of each individual galaxy. This campaign is ten- to one-hundred-times more powerful (depending on your parameters) than any prior survey of its kind.

“Some galaxies are furiously bursting with new stars while others have long ago used up most of their fuel for star formation. The origin of this diversity may very likely lie in the properties of the stellar nurseries themselves,” said Erik Rosolowsky, an astronomer at the University of Alberta in Canada and a co-Principal Investigator of the PHANGS-ALMA research team.

He presented initial findings of this research at the 233rd meeting of the American Astronomical Society being held this week in Seattle, Washington. Several papers based on this campaign have also been published in The Astrophysical Journal and the Astrophysical Journal Letters [Papers are listed below].

“Previous observations with earlier generations of radio telescopes provide some crucial insights about the nature of cold, dense stellar nurseries,” Rosolowsky said. “These observations, however, lacked the sensitivity, fine-scale resolution, and power to study the entire breadth of stellar nurseries across the full population of local galaxies. This severely limited our ability to connect the behavior or properties of individual stellar nurseries to the properties of the galaxies that they live in.”

For decades, astronomers have speculated that there are fundamental differences in the way disk galaxies of various sizes convert hydrogen into new stars. Some astronomers theorize that larger, and generally older galaxies, are not as efficient at stellar production as their smaller cousins. The most logical explanation would be that these big galaxies have less efficient stellar nurseries. But testing this idea with observations has been difficult.

For the first time, ALMA is allowing astronomers to conduct the necessary wide-ranging census to determine how the large-scale properties (size, motion, etc.) of a galaxy influence the cycle of star formation on the scale of individual molecular clouds. These clouds are only about a few tens to a few hundreds of light-years across, which is phenomenally small on the scale of an entire galaxy, especially when seen from millions of light-years away.

“Stars form more efficiently in some galaxies than others, but the dearth of high-resolution, cloud-scale observations meant our theories were weakly tested, which is why these ALMA observations are so critical,” said Adam Leroy, an astronomer at The Ohio State University and co-Principal Investigator on the PHANGS-ALMA team.

Part of the mystery of star formation, the astronomers note, has to do with the interstellar medium – all the matter and energy that fills the space between the stars.

Astronomers understand that there is an ongoing feedback loop in and around the stellar nurseries. Within these clouds, pockets of dense gas collapse and form stars, which disrupts the interstellar medium.

“Indeed, comparing early PHANGS observations with the locations of newly formed stars shows that the newly formed stars quickly destroy their birth clouds,” said Rosolowsky. “The PHANGS team is studying how this disruption plays out in different types of galaxies, which may be a key factor in star-forming efficiency.”

For this research, ALMA is observing molecules of carbon monoxide (CO) from all relatively massive, generally face-on spiral galaxies visible from the Southern Hemisphere. Molecules of CO naturally emit the millimeter-wavelength light that ALMA can detect. They are particularly effective at highlighting the location of star-forming clouds.

“ALMA is a stunningly efficient machine to map carbon monoxide over large areas in nearby galaxies,” said Leroy. “It was able to perform this survey because of the combined power of the 12-meter dishes, which study fine-scale features, and the smaller, 7-meter dishes at the center of the array, which are sensitive to large-scale features, essentially filling in the gaps.”

A companion survey, PHANGS-MUSE, is using the Very Large Telescope to obtain optical imaging of the first 19 galaxies observed by ALMA.

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, with an elevation of 2,635 metres (8,645 ft) above sea level,

MUSE stands for the Multi-Unit Spectroscopic Explorer.

ESO MUSE on the VLT on Yepun (UT4)

Another survey, PHANGS-HST uses the Hubble Space Telescope to survey 38 of these galaxies to find their youngest stellar clusters.

NASA/ESA Hubble Telescope

Together, these three surveys give a startlingly complete picture of how well galaxies form stars by probing cold molecular gas, its motion, the location of ionized gas (regions where stars are already forming), and the galaxies’ complete stellar populations.

“In astronomy, we have no ability to watch the cosmos change over time; the timescales simply dwarf human existence,” noted Rosolowsky. “We can’t watch one object forever, but we can observe hundreds of thousands of star-forming clouds in galaxies of different sizes and ages to infer how galactic evolution works. That is the real value of the PHANGS-ALMA campaign.”

“We also look at thousands to tens of thousands of star-forming regions within each galaxy, catching them across their life cycle. This lets us build a picture of the birth and death of stellar nurseries across galaxies, something almost impossible before ALMA,” added Leroy.

So far, PHANGS-ALMA has studied about 100,000 Orion Nebula-like objects in the nearby universe. It is expected that the campaign will eventually observe around 300,000 star-forming regions.

These results are being published in a series of papers in The Astrophysical Journal and the Astrophysical Journal Letters. Already accepted and published:

“Cloud-scale Molecular Gas Properties in 15 Nearby Galaxies,” J. Sun, et al., 2018 June. 25, The Astrophysical Journal [http://iopscience.iop.org/article/10.3847/1538-4357/aac326]

“Star Formation Efficiency per Free-fall Time in nearby Galaxies,” D. Utomo, et al., 2018 July 11, Astrophysical Journal Letters [http://iopscience.iop.org/article/10.3847/2041-8213/aacf8f/meta]

“A 50 pc Scale View of Star Formation Efficiency across NGC 628,” K. Kreckel, et al., 2018 August 14, Astrophysical Journal Letters [http://iopscience.iop.org/article/10.3847/2041-8213/aad77d]

IMAGES

Six ALMA-imaged galaxies out of a collection of the 74. The images were taken as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton

ALMA image of galaxy NGC 4321, also known as Messier 100, an intermediate spiral galaxy located about 55 million light-years from Earth in the constellation Coma Berenices. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton

ALMA image of NGC 628, also known as Messier 74, a spiral galaxy in the constellation Pisces, located approximately 32 million light-years from Earth. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton

Composite ALMA (orange) and Hubble (blue) image of NGC 628, also known as Messier 74, a spiral galaxy in the constellation Pisces, located approximately 32 million light-years from Earth. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: NRAO/AUI/NSF, B. Saxton: ALMA (ESO/NAOJ/NRAO); NASA/Hubble

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 Discover Early Protostar With a Warped Disk”

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

From ALMA

31 December, 2018

Jens Wilkinson
RIKEN Global Communications
Japan
Phone: +81-(0)48-462-1225
Email: pr@riken.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

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

Artist’s impression of a warped disk around a protostar. ALMA observed the protostar IRAS04368+2557 in the dark cloud L1527 and discovered that the protostar has a disk with two misaligned parts. Credit: RIKEN

Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, researchers have observed, for the first time, a warped disk around an infant protostar that formed just several tens of thousands of years ago. This implies that the misalignment of planetary orbits in many planetary systems, including our own, may be caused by distortions in the planet-forming disk early in their existence.

The planets in the Solar System orbit the Sun in planes that are at most about seven degrees offset from the equator of the Sun itself. It has been known for some time that many extrasolar systems have planets that are not lined up in a single plane or with the equator of the star. One explanation for this is that some of the planets might have been affected by collisions with other objects in the system or by stars passing by the system, ejecting them from the initial plane.

However, the possibility remained that the formation of planets out of the normal plane was actually caused by a warping of the star-forming cloud out of which the planets were born. Recently, images of protoplanetary disks, rotating disks where planets form around a star, have in fact showed such warping. But it was still unclear how early this happened.

In the latest findings, published in Nature, the group from the and Chiba University in Japan have discovered that L1527; an infant protostar still embedded within a cloud, has a disk that has two parts, an inner one rotating in one plane, and an outer one in a different plane. The disk is very young and still growing. L1527, which is about 450 light years away in the Taurus Molecular Cloud, is a good object for study as it has a disk that is nearly edge-on to our view.

According to Nami Sakai, who led the research group, “this observation shows that it is conceivable that the misalignment of planetary orbits can be caused by a warp structure formed in the earliest stages of planetary formation. We will have to investigate more systems to find out if this is a common phenomenon or not.”

The remaining question is what caused the warping of the disk. Sakai suggests two reasonable explanations. “One possibility,” she says, “is that irregularities in the flow of gas and dust in the protostellar cloud are still preserved and manifest themselves as the warped disk. A second possibility is that the magnetic field of the protostar is in a different plane from the rotational plane of the disk, and that the inner disk is being pulled into a different plane from the rest of the disk by the magnetic field.” She says they plan further work to determine which is responsible for the warping of the disk.

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: “Fragmenting Disk Gives Birth to Binary Star ‘Odd Couple’”

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

From ALMA

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that two young stars forming from the same swirling protoplanetary disk may be twins — in the sense that they came from the same parent cloud of star-forming material. Beyond that, however, they have shockingly little in common.

The main, central star of this system, which is located approximately 11,000 light-years from Earth, is truly colossal — a full 40 times more massive than the Sun. The other star, which ALMA recently discovered just beyond the central star’s disk, is a relatively puny one-eightieth (1/80) that mass.

Their striking difference in size suggests that they formed by following two very different paths. The more massive star took the more traditional route by collapsing under gravity out of a dense “core” of gas. The smaller one likely followed the road less traveled by – at least for stars – by accumulating mass from a portion of the disk that “fragmented” away as it matured, a process that may have more in common with the birth of gas-giant planets.

“Astronomers have known for a long time that most massive stars orbit one or more other stars as partners in a compact system, but how they got there has been a topic of conjecture,” said Crystal Brogan, an astronomer with the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, and a co-author on the study. “With ALMA, we now have evidence that the disk of gas and dust that encompasses and feeds a growing massive star also produces fragments at early stages that can form a secondary star.”

The main object, known as MM 1a, is a previously identified young massive star surrounded by a rotating disk of gas and dust. A faint protostellar companion to this object, MM 1b, was newly detected by ALMA just outside the MM 1a protoplanetary disk. The team believes this is one of the first examples of a fragmented disk to be detected around a massive young star.

“This ALMA observation opens new questions, such as ‘Does the secondary star also have a disk?’ and ‘How fast can the secondary star grow?’ The amazing thing about ALMA is that we have not yet used its full capabilities in this area, which will someday allow us to answer these new questions,” said co-author Todd Hunter, who is also with the NRAO in Charlottesville.

Stars form within large clouds of gas and dust in interstellar space. When these clouds collapse under gravity, they begin to rotate faster, forming a disk around them.

“In low-mass stars like our Sun, it is in these disks that planets can form,” said John Ilee, an astronomer at Leeds University in England and lead author on the study. “In this case, the star and disk we have observed are so massive that, rather than witnessing a planet forming in the disk, we are seeing another star being born.”

By observing the millimeter wavelength light naturally emitted by the dust, and subtle shifts in the frequency of light emitted by the gas, the researchers were able to calculate the mass of MM 1a and MM 1b.

Their work is published in The Astrophysical Journal Letters.

“Many older massive stars are found with nearby companions,” added Ilee. “But binary stars are often very equal in mass, and so likely formed together as siblings. Finding a young binary system with a mass ratio of 80-to-1 is very unusual and suggests an entirely different formation process for both objects.”

The favored formation process for MM 1b occurs in the outer regions of cold, massive disks. These “gravitationally unstable” disks are unable to hold themselves up against the pull of their own gravity, collapsing into one – or more – fragments.

The researchers note that newly discovered young star MM 1b could also be surrounded by its own circumstellar disk, which may have the potential to form planets of its own – but it will need to be quick. “Stars as massive as MM 1a only live for around a million years before exploding as powerful supernovae, so while MM 1b may have the potential to form its own planetary system in the future, it won’t be around for long,” Ilee concluded.

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 ALMA: “ALMA Confirms Comets Forge Organic Molecules in Their Dusty Atmospheres”

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

From ALMA

7 August, 2014 [Retrieved from the ALMA web site]

Valeria Foncea
Education and Public Outreach Officer
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 467 6258
Cell: +56 9 75871963
Email: vfoncea@alma.cl

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 434.242.9559
E-mail: cblue@nrao.edu

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory Tokyo, Japan
Tel: +81 422 34 3630
E-mail: hiramatsu.masaaki@nao.ac.jp

Richard Hook
Public Information Officer, ESO
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org

Fig. 1: Approximate location of Comet ISON in our Solar System at the time of the ALMA observations. Credit: B. Saxton (NRAO/AUI/NSF); NASA/ESA Hubble; M. Cordiner, NASA, et al.

An international team of scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) has made incredible 3D images of the ghostly atmospheres surrounding comets ISON and Lemmon. These new observations provided important insights into how and where comets forge new chemicals, including intriguing organic compounds.

Comets contain some of the oldest and most pristine materials in our Solar System. Understanding their unique chemistry could reveal much about the birth of our planet and the origin of organic compounds that are the building blocks of life. ALMA’s high-resolution observations provided a tantalizing 3D perspective of the distribution of the molecules within these two cometary atmospheres, or comas.

“We achieved truly first-of-a-kind mapping of important molecules that help us understand the nature of comets,” said team leader Martin Cordiner, a Catholic University of America astrochemist working at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The critical 3D component of the ALMA observations was made by combining high-resolution, two-dimensional images of the comets with high-resolution spectra obtained from three important organic molecules – hydrogen cyanide (HCN), hydrogen isocyanide (HNC), and formaldehyde (H2CO). These spectra were taken at every point in each image. They identified not only the molecules present but also their velocities, which provided the third dimension, indicating the depths of the cometary atmospheres.

The new results revealed that HCN gas flows outward from the nucleus quite evenly in all directions, whereas HNC is concentrated in clumps and jets. ALMA’s exquisite resolution could clearly resolve these clumps moving into different regions of the cometary comas on a day-to-day and even hour-to-hour basis. These distinctive patterns confirm that the HNC and H2CO molecules actually form within the coma and provide new evidence that HNC may be produced by the breakdown of large molecules or organic dust.

“Understanding organic dust is important, because such materials are more resistant to destruction during atmospheric entry, and some could have been delivered intact to the early Earth, thereby fueling the emergence of life,” said Michael Mumma, director of the Goddard Center for Astrobiology and a co-author on the study. “These observations open a new window on this poorly known component of cometary organics.”

“So, not only does ALMA let us identify individual molecules in the coma, it also gives us the ability to map their locations with great sensitivity,” said Anthony Remijan, an astronomer with the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, and a study co-author.

The observations, published in The Astrophysical Journal Letters, were also significant because modest comets like Lemmon and ISON contain relatively low concentrations of these crucial molecules, making them difficult to probe in depth with Earth-based telescopes. The few comprehensive studies of this kind so far have been conducted on extremely bright comets, such as Hale-Bopp. The present results extend them to comets of only moderate brightness.

Comet ISON (formally known as C/2012 S1) was observed with ALMA on November 15-17, 2013, when it was only 75 million kilometers from the Sun (about half the distance of the Earth to the Sun). Comet Lemmon (formally known as C/2012 F6) was observed on June 1-2, 2013, when it was 224 million kilometers from the Sun (about 1.5 times the distance of the Earth to the Sun).

Fig. 5: Visualization with ALMA of the 3D distribution of the organic molecule HCN in the atmosphere of comet Lemmon. Credit: Visualization by Brian Kent (NRAO/AUI/NSF)

“The high sensitivity achieved in these studies paves the way for observations of perhaps hundreds of the dimmer or more distant comets,” said Goddard’s Stefanie Milam, a study co-author. “The findings suggest that it should also be possible to map more complex molecules that have so far eluded detection in comets.”

This research was funded by the NASA Astrobiology Institute through the Goddard Center for Astrobiology and by NASA’s Planetary Atmospheres and Planetary Astronomy programs.

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 ALMA: “Cometary Belt around Distant Multi-Planet System Hints at Hidden or Wandering Planets”

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

From ALMA

17 May, 2016 [Retrieved from the ALMA web site]

Valeria Foncea
Education and Public Outreach Officer
Joint ALMA Observatory Santiago – Chile
Phone: +56 2 2467 6258
Cell phone: +56 9 7587 1963
Email: valeria.foncea@alma.cl

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

Richard Hook
Public Information Officer, ESO
Garching bei München, Germany
Phone: +49 89 3200 6655
Cell phone: +49 151 1537 3591
Email: rhook@eso.org

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

ALMA image of dusty cometary ring around HR 8799, the only star where multiple planets have been imaged. The new data suggest the planets either migrated or another undiscovered planet is present. The zoom-in portion of the image, taken with ESO’s Very Large Telescope, shows the location of the known planets in this system in relation to a graphical representation of the central star. Credit: Booth et al., ALMA (NRAO/ESO/NAOJ); A. Zurlo, et al

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

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made the first high-resolution image of the cometary belt (a region analogous to our own Kuiper belt) around HR 8799, the only star where multiple planets have been imaged directly. The shape of this dusty disk, particularly its inner edge, is surprisingly inconsistent with the orbits of the planets, suggesting that either they changed position over time or there is at least one more planet in the system yet to be discovered.

“This data really allow us to see the inner edge of this disk for the first time,” explains Mark Booth from Pontificia Universidad Católica de Chile and lead author of the study. “By studying the interactions between the planets and the disk, this new observation shows that either the planets that we see have had different orbits in the past or there is at least one more planet in the system that is too small to have been detected.”

The disk, which fills a region 150 to 420 times the Sun-Earth distance, is produced by the ongoing collisions of cometary bodies in the outer reaches of this star system. ALMA was able to image the emission from millimeter-size debris in the disk; according to the researchers, the small size of these dust grains suggests that the planets in the system are larger than Jupiter. Previous observations with other telescopes at shorter wavelengths did not detect this discrepancy in the disk. It is not clear if this difference is due to the low resolution of the previous observations or because different wavelengths are sensitive to different grain sizes, which would be distributed slightly differently.

HR 8799 is a young star approximately 1.5 times the mass of the Sun located 129 light-years from Earth in the direction of the constellation Pegasus.

“This is the very first time that a multi-planet system with orbiting dust is imaged, allowing for direct comparison with the formation and dynamics of our own Solar System,” explains Antonio Hales, co-author of the study from the National Radio Astronomy Observatory in Charlottesville, Virginia.

Additional information

These results were published in the Monthly Notices of the Royal Astronomical Society titled “Resolving the Planetesimal Belt of HR 8799 with ALMA” by Booth et al., May 2016.
Preprint: http://arxiv.org/abs/1603.04853

The research team was composed by Mark Booth ([1], [2]), Andrés Jordán ([1], [3]), Simón Casassus ([2], [4]), Antonio S. Hales ([5], [6]), William R. F. Dent ([5]), Virginie Faramaz ([1]), Luca Matrà ([7],[8]), Denis Barkats ([9]), Rafael Brahm ([1], [3]) Jorge Cuadra ([1], [2]).

[1] Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile
[2] Millennium Nucleus “Protoplanetary Disks”
[3] Millennium Institute of Astrophysics, Vicuña Mackenna 4860, Santiago, Chile
[4] Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
[5] Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura 763-0355, Santiago, Chile
[6] National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, Virginia, 22903-2475, USA
[7] Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
[8] European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago, Chile
[9] Harvard University, 60 Garden Street, Cambridge, MA 02138, USA

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 ALMA: “ALMA Gives Christmas Comet Its Close-up”

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

From ALMA

20 December, 2018

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

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 comet 46P/Wirtanen taken on December 2 as the comet approached Earth. The ALMA image shows the concentration and distribution of hydrogen cyanide (HCN) molecules near the center of the comet’s coma. Credit: ALMA (ESO/NAOJ/NRAO); M. Cordiner, NASA/CUA

As comet 46P/Wirtanen neared Earth on December 2, astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) took a remarkably close look at its innermost regions. ALMA imaged the comet when it was approximately 16.5 million kilometers from Earth. At its closet on December 16, the comet – one of the brightest in years — was approximately 11.4 million kilometers from Earth, or 30 times the distance from the Earth to the moon.

“This comet is causing a stir in the professional and amateur astronomy communities due to its combined brightness and proximity, which allows us to study it in unprecedented detail” said NASA’s Martin Cordiner, who led the team that made the ALMA observations. “As the comet drew nearer to the Sun, its icy body heated up, releasing water vapor and various other particles stored inside, forming the characteristic puffed-up coma and elongated tail.”

The ALMA image of comet 46P/Wirtanen zooms-in to very near its nucleus – the solid “dirty snowball” of the comet itself — to image the natural millimeter-wavelength “glow” emitted by molecules of hydrogen cyanide (HCN), a simple organic molecule that forms an ethereal atmosphere around the comet. ALMA, using its remarkable ability to see fine details, was able to detect and image the fine-scale distribution of this particular molecule.

The HCN image shows a compact region of gas and an extended, diffuse, and somewhat asymmetrical, pattern in the inner portion of the coma. Due to the extreme proximity of this comet, most of the extended coma is resolved out, so these observations are only sensitive to the innermost regions, in the immediate vicinity of the nucleus.

The astronomers also performed observations of more complex molecules on Dec 9, when the comet was 13.6 million kilometers from Earth.

Comet 46P/Wirtanen orbits the Sun once every five-and-a-half years, which is remarkably brisk compared to its more famous cousin Halley’s Comet, which has an orbital period of about 75 years. Other bright comets can have periods that are on the order of hundreds and even thousands of years. The comet may yet be visible to the naked eye.

For comparison, an optical view of the comet taken by an amateur astrophotographer is shown.

An optical image of comet 46P/Wirtanen taken from Chiefland, Florida, on December 4, 2018. Camera details: Canon 6D camera, MN190mm astrograph telescope. Credit: Derek Demeter, Emil Buehler Planetarium

Though they appear to be similar, the ALMA image spans an area of the sky only about 5 arcseconds – about 1000 times smaller than the optical image – meaning ALMA is looking at the very fine-scale features in the coma.

Side-by-side comparison shows an ALMA image of comet 46P/Wirtanen (left) and an optical image (right). The ALMA image has approximately 1000 times the resolution of the optical image and zooms in on the inner portion of the comet’s diffuse coma. Credit: ALMA (ESO/NAOJ/NRAO), M. Cordiner, NASA/CUA; Derek Demeter, Emil Buehler Planetarium

This and previous observations of comets with ALMA confirm that they are rich in organic molecules and may therefore have seeded the early Earth with the chemical building blocks of life.

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.