From ALMA: “ALMA Gains New Capability in its First VLBI Observation “

ALMA

Thursday, 05 March 2015
Contact:

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

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

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

ALMA, the Atacama Large Millimeter/submillimeter Array, has successfully combined its immense collecting area and sensitivity with that of APEX (Atacama Pathfinder Experiment) to create a new, single instrument through a process known as Very Long Baseline Interferometry (VLBI). This first successful observation using VLBI with ALMA used a baseline of 2.1 km, and was an essential proof-of-concept test for the planned Event Horizon Telescope, which eventually will include a global network of millimetre-wavelength telescopes. Crédito: Clem & Adri Bacri-Normier (wingsforscience.com)/ESO

The Atacama Large Millimeter/submillimeter Array (ALMA) recently combined its immense collecting area and sensitivity with that of the APEX (Atacama Pathfinder Experiment) Telescope to create a new, single instrument through a process known as Very Long Baseline Interferometry (VLBI). In VLBI, data from two independent telescopes are combined to form a virtual telescope that spans the geographic distance between them, yielding extraordinary magnifying power.

ESO/APEX

The new ALMA/APEX observation, which took place on January 13, was an essential proof-of-concept test for the planned Event Horizon Telescope (EHT), which eventually will include a global network of millimeter-wavelength telescopes.

EHT

When fully assembled, the EHT – with ALMA as the largest and most sensitive site – will form an Earth-size telescope with the magnifying power required to see details at the edge of the supermassive black hole at the center of the Milky Way.

For this first-of-its-kind observation, ALMA and the nearby APEX telescope simultaneous studied a quasar known as 0522-364 – a distant galaxy commonly used for testing in radio astronomy due to its remarkable brightness. To ensure the telescopes were in sync, ALMA used its newly installed and exquisitely precise atomic clock (see ALMA announcement) to time-code the data as it was collected. This is essential for VLBI because it enables data taken at different geographical locations on different telescopes to be precisely matched and accurately integrated.

The full dataset from the observing run was captured on hard drives and flown back to MIT where it will undergo full analysis. Due to the vast amount of information collected, air travel is the fastest means of data transmission, even faster than the fastest international Internet connection.

“The entire team is immensely gratified at achieving this success on the first VLBI attempt with ALMA. It marks a huge step toward making first images of a black hole with the Event Horizon Telescope,” said Shep Doeleman, the principal investigator of the ALMA Phasing Project and assistant director of the Massachusetts Institute of Technology’s Haystack Observatory.

This most recent work was carried out by a team made up of members from the ALMA Phasing Project, the Joint ALMA Observatory, the Smithsonian Astrophysical Observatory and the APEX Telescope.

See the full article here.

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 ESO And ALMA: “An Old-looking Galaxy in a Young Universe”

ESO/NRAO/NAOJ/ALMA
ALMA

European Southern Observatory

ESO/VLT

2 March 2015

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

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

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

Darach Watson
Niels Bohr Institute
University of Copenhagen, Denmark
Tel: +45 2480 3825
Email: darach@dark-cosmology.dk

Kirsten K. Knudsen
Chalmers University of Technology
Onsala, Sweden
Tel: +46 31 772 5526
Cell: +46 709 750 956
Email: kirsten.knudsen@chalmers.se

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

One of the most distant galaxies ever observed has provided astronomers with the first detection of dust in such a remote star-forming system and tantalising evidence for the rapid evolution of galaxies after the Big Bang. The new observations have used ALMA to pick up the faint glow from cold dust in the galaxy A1689-zD1 and used ESO’s Very Large Telescope to measure its distance.

A team of astronomers, led by Darach Watson from the University of Copenhagen, used the Very Large Telescope’s X-shooter instrument along with the Atacama Large Millimeter/submillimeter Array (ALMA) to observe one of the youngest and most remote galaxies ever found.

X-shooter

They were surprised to discover a far more evolved system than expected. It had a fraction of dust similar to a very mature galaxy, such as the Milky Way. Such dust is vital to life, because it helps form planets, complex molecules and normal stars.

The target of their observations is called A1689-zD1 [1]. It is observable only by virtue of its brightness being amplified more than nine times by a gravitational lens in the form of the spectacular galaxy cluster, Abell 1689, which lies between the young galaxy and the Earth. Without the gravitational boost, the glow from this very faint galaxy would have been too weak to detect.

We are seeing A1689-zD1 when the Universe was only about 700 million years old — five percent of its present age [2]. It is a relatively modest system — much less massive and luminous than many other objects that have been studied before at this stage in the early Universe and hence a more typical example of a galaxy at that time.

A1689-zD1 is being observed as it was during the period of reionisation, when the earliest stars brought with them a cosmic dawn, illuminating for the first time an immense and transparent Universe and ending the extended stagnation of the [cosmic] Dark Ages. Expected to look like a newly formed system, the galaxy surprised the observers with its rich chemical complexity and abundance of interstellar dust.

“After confirming the galaxy’s distance using the VLT,” said Darach Watson, “we realised it had previously been observed with ALMA. We didn’t expect to find much, but I can tell you we were all quite excited when we realised that not only had ALMA observed it, but that there was a clear detection. One of the main goals of the ALMA Observatory was to find galaxies in the early Universe from their cold gas and dust emissions — and here we had it!”

This galaxy was a cosmic infant — but it proved to be precocious. At this age it would be expected to display a lack of heavier chemical elements — anything heavier than hydrogen and helium, defined in astronomy as metals. These are produced in the bellies of stars and scattered far and wide once the stars explode or otherwise perish. This process needs to be repeated for many stellar generations to produce a significant abundance of the heavier elements such as carbon, oxygen and nitrogen.

Surprisingly, the galaxy A1689-zD1 seemed to be emitting a lot of radiation in the far infrared [3], indicating that it had already produced many of its stars and significant quantities of metals, and revealed that it not only contained dust, but had a dust-to-gas ratio that was similar to that of much more mature galaxies.

“Although the exact origin of galactic dust remains obscure,” explains Darach Watson, “our findings indicate that its production occurs very rapidly, within only 500 million years of the beginning of star formation in the Universe — a very short cosmological time frame, given that most stars live for billions of years.”

The findings suggest A1689-zD1 to have been consistently forming stars at a moderate rate since 560 million years after the Big Bang, or else to have passed through its period of extreme starburst very rapidly before entering a declining state of star formation.

Prior to this result, there had been concerns among astronomers that such distant galaxies would not be detectable in this way, but A1689-zD1 was detected using only brief observations with ALMA.

Kirsten Knudsen (Chalmers University of Technology, Sweden), co-author of the paper, added, “This amazingly dusty galaxy seems to have been in a rush to make its first generations of stars. In the future, ALMA will be able to help us to find more galaxies like this, and learn just what makes them so keen to grow up.”
Notes

[1] This galaxy was noticed earlier in the Hubble images, and suspected to be very distant, but the distance could not be confirmed at that time.

[2] This corresponds to a redshift of 7.5.

[3] This radiation is stretched by the expansion of the Universe into the millimetre wavelength range by the time it gets to Earth and hence can be detected with ALMA.
More information

This research was presented in a paper entitled A dusty, normal galaxy in the epoch of reionization by D. Watson et al., to appear online in the journal Nature on 2 March 2015.

The team is composed of D. Watson (Niels Bohr Institute, University of Copenhagen, Denmark), L. Christensen (University of Copenhagen), K. K. Knudsen (Chalmers University of Technology, Sweden), J. Richard (CRAL, Observatoire de Lyon, Saint Genis Laval, France), A. Gallazzi (INAF-Osservatorio Astrofisico di Arcetri, Firenze, Italy) and M. J. Michalowski (SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, UK).

See the full article here.

Hubble’s results

Abell 1689
This new Hubble image shows galaxy cluster Abell 1689. It combines both visible and infrared data from Hubble’s Advanced Camera for Surveys (ACS) with a combined exposure time of over 34 hours (image on left over 13 hours, image on right over 20 hours) to reveal this patch of sky in greater and striking detail than in previous observations.

This image is peppered with glowing golden clumps, bright stars, and distant, ethereal spiral galaxies. Material from some of these galaxies is being stripped away, giving the impression that the galaxy is dripping, or bleeding, into the surrounding space. Also visible are a number of electric blue streaks, circling and arcing around the fuzzy galaxies in the centre.
These streaks are the telltale signs of a cosmic phenomenon known as gravitational lensing. Abell 1689 is so massive that it bends and warps the space around it, affecting how light from objects behind the cluster travels through space. These streaks are the distorted forms of galaxies that lie behind the cluster.
Date 12 September 2013
NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Blakeslee (NRC Herzberg Astrophysics Program, Dominion Astrophysical Observatory), and H. Ford (JHU)

Hubble

Hubble’s ACS

Please help promote STEM in your local schools.

Stem Education Coalition
Visit ESO in Social Media-

Facebook

Twitter

YouTube

ESO, European Southern Observatory, builds and operates a suite of the world’s most advanced ground-based astronomical telescopes.

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 Revealed Calm Pockets Protecting Organic Molecules”

ALMA

Thursday, 26 February 2015
Nicolás Lira
Education and Public Outreach Assistant
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 467 6519
Cell: +56 9 9445 7726
Email: nlira@alma.cl

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

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

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

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

Hubble

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

Hubble Space Telescope image of NGC 1068

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

Molecules Reveal Clues to Galactic Environments

Interstellar gas contains a wide variety of molecules and its chemical composition differs widely depending on the environment. For example, an active star forming region with a temperature higher than the surrounding environment stimulates the production of certain types of molecules by chemical reactions which are difficult to take place in a cold temperature region. This enables researchers to probe the environment (temperature and density) of a target region by studying the molecular chemical compositions in it. Since each molecule has its own frequency spectrum, we can identify the chemical composition and the environment of a remote target object through observations with a radio telescope.

From this perspective, astronomers have been actively working on the starburst regions of galaxies [1] and the surrounding region of the active galactic nuclei (AGN) at the center of galaxies, called circumnuclear disk (CND) [2]. These regions are very important in understanding the evolution of galaxies, and radio observations of molecular emissions are essential to explore its mechanism and environment [3]. However, the weak radio emission from molecules often made the observations difficult and took many days for signal detection using conventional radio telescopes.

ALMA Observations Trace Molecules

A research team led by Shuro Takano at the National Astronomical Observatory of Japan (NAOJ) and Taku Nakajima at Nagoya University observed the spiral galaxy M77 in the direction of the constellation of Cetus (the Whale) about 47 million light years away with ALMA. M77 is known to have an active galactic nucleus at its center which is surrounded by a starburst ring with a radius of 3500 light years.

Since the research team had already conducted radio observations of various molecular emissions in this galaxy with the 45 meters telescope at the Nobeyama Radio Observatory of NAOJ, they aimed to develop their research further with ALMA’s extreme sensitivity, high-fidelity and ability to observe wideband in multiple wavelenght along with a high spatial resolution; and identify the difference in chemical composition between AGNs and starburst regions.

Nobeyama Radio Observatory of NAOJ

ALMA observations clearly revealed the distributions of nine types of molecules in the circumnuclear disk and in the starburst ring. “In this observation, we used only 16 antennas, which are about one-fourth of the complete number of ALMA antennas, but it was really surprising that we could get so many molecular distribution maps in less than two hours. We have never obtained such a quantity of maps in one observation,” says Takano, the leader of the research team.

The results show that the molecular distribution varies according to the type of molecule. While carbon monoxide (CO) is distributed mainly in the starburst ring, five types of molecules, including complex organic molecules such as cyanoacetylene (HC3N) and acetonitrile (CH3CN) are concentrated in the circumnuclear disk. In addition, carbon monosulfide (CS) and methanol (CH3OH) are distributed both in the starburst ring and the circumnuclear disk. ALMA provided the first high resolution observation of the five types of molecules in M77 and revealed that they are concentrated in the circumnuclear disk.

Shielding Complex Organics around a Black Hole

The supermassive black hole devours surrounding materials by its strong gravity and generates such a hot disk around him that it emits intense X-rays or UV photons. When complex organic molecules are exposed to strong X-rays or UV photons, their multiple atomic bonds are broken and the molecules destroyed. This is why the circumnuclear disk was thought to be a very difficult environment for organic molecules to survive. ALMA observations, however, proved the contrary: Complex organic molecules are abundant in the circumnuclear disk.

“It was quite unexpected that acetonitrile (CH3CN) and cyanoacetylene (HC3N), which have a large number of atoms, are concentrated in the circumnuclear disk,” said Nakajima.

The research team assumes that organic molecules remain intact in the circumnuclear disk due to a large amount of gas, which act as a shield from X-rays and UV photons, while organic molecules cannot survive the exposure to the strong UV photons in the starburst region where the gas density is lower.

The researchers point out that these results are a significant first step in understanding the structure, temperature, and density of gas surrounding the active black hole in M77. “We expect that future observations with wider bandwidth and higher resolution will show us the whole picture of our target object in further detail and achieve even more remarkable results,” says Takano.

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

These observation results were published as Takano et al. Distributions of molecules in the circumnuclear disk and surrounding starburst ring in the Seyfert galaxy NGC 1068 observed with ALMA (in the astronomical journal Publications of the Astronomical Society of Japan (PASJ), issued in July 2014) and as Nakajima et al. A Multi-Transition Study of Molecules toward NGC 1068 based on High-Resolution Imaging Observations with ALMA (in PASJ issued in February 2015).

Notes

[1] In the Milky Way Galaxy which we live in, one sun-like star is generated per year on average, while several hundred sun-like stars are churned out each year in a starburst region.

[2] It is believed that most of the galaxies have in their center a supermassive black hole of millions to hundreds of millions of solar mass. Among them, Active Galactic Nuclei (AGN) represents a type of supermassive black hole which are gulping down surrounding gas very actively and emitting some amount of gas as high-speed gas flows (jets).

[3] For example, a research team led by Takuma Izumi and Kotaro Kohno at the University of Tokyo, both of whom are engaged in this research, suggests that there is enhanced emission of hydrogen cyanide (HCN) from the supermassive black hole in the barred spiral galaxy NGC1097 by the past ALMA observations.

Reference: October 24, 2013, Press release “Unique Chemical Composition Surrounding Supermassive Black Hole—A Step toward Development of New Black Hole Exploration Method”

This research was conducted by: Shuro TAKANO (NAOJ Nobeyama Radio Observatory/SOKENDAI); Taku NAKAJIMA (Solar-Terrestrial Environment Laboratory, Nagoya University); Kotaro KOHNO (Institute of Astronomy, The University of Tokyo/Research Center for the Early Universe); Nanase HARADA (Academia Sinica Institute of Astronomy and Astrophysics [At the time of writing: Max Planck Institute for Radio Astronomy]); Eric HERBST (University of Virginia); Yoichi TAMURA (Institute of Astronomy, The University of Tokyo); Takuma IZUMI (Institute of Astronomy, The University of Tokyo); Akio TANIGUCHI (Institute of Astronomy, The University of Tokyo); Tomoka TOSAKI (Joetsu University of Educaction).

See the full article here.

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 Sees Super Stellar Nurseries at Heart of Sculptor Galaxy”

ALMA

Monday, 16 February 2015
Education and Public Outreach Assistant
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 467 6519
Cell: +56 9 9445 7726
Email: nlira@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

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

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

What is the recipe for starburst? Astronomers studied NGC 253 with ALMA to find out. These new ALMA data reveal a diffuse envelope of carbon monoxide gas (shown in red), which surrounds stellar nurseries — regions of active star formation (in yellow). By dissecting these regions with ALMA, astronomers are uncovering clues to the processes and conditions that drive furious star formation. The ALMA data are superimposed on a Hubble image that covers part of the same region. Credit: B. Saxton (NRAO/AUI/NSF); ALMA (NRAO/ESO/NAOJ), A. Leroy; STScI/NASA, ST-ECF/ESA, CADC/NRC/CSA

Starburst galaxies transmute gas into new stars at a dizzying pace – up to 1,000 times faster than typical spiral galaxies like the Milky Way. To help understand why some galaxies “burst” while others do not, an international team of astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to dissect a cluster of star-forming clouds at the heart of NGC 253, one of the nearest starburst galaxies to the Milky Way.

The Sculptor Galaxy taken with the ESO VISTA telescope at the Paranal Observatory in Chile.

ESO/Vista telescope

“All stars form in dense clouds of dust and gas,” said Adam Leroy, an astronomer formerly with the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, and now with the Ohio State University (OSU) in Columbus. “Until now, however, scientists struggled to see exactly what was going on inside starburst galaxies that distinguished them from other star-forming regions.”

ALMA changes that by offering the power to resolve individual star-forming structures, even in distant systems. As an early demonstration of this capability, Leroy and his colleagues mapped the distributions and motions of multiple molecules in clouds at the core of NGC 253, also known as the Sculptor Galaxy.

Sculptor, a disk-shape galaxy currently undergoing intense starburst, is located approximately 11.5 million light-years from Earth, which is remarkably nearby for such an energetic star factory. This proximity makes Sculptor an excellent target for detailed study.

“There is a class of galaxies and parts of galaxies, we call them starbursts, where we know that gas is just plain better at forming stars,” noted Leroy. “To understand why, we took one of the nearest such regions and pulled it apart – layer by layer – to see what makes the gas in these places so much more efficient at star formation.”

Animation of ALMA data reveals a diffuse envelope of carbon monoxide gas (shown in red), which surrounds stellar nurseries — regions of active star formation (in yellow). By dissecting these regions with ALMA, astronomers are uncovering clues to the processes and conditions that drive furious star formation. The ALMA data are superimposed on a Hubble image that covers part of the same region. Credit: B. Saxton (NRAO/AUI/NSF); ALMA (NRAO/ESO/NAOJ), A. Leroy; STScI/NASA, ST-ECF/ESA, CADC/NRC/CSA

ALMA’s exceptional resolution and sensitivity allowed the researchers to first identifying ten distinct stellar nurseries inside the heart of Sculptor, something that was remarkably hard to accomplish before because earlier telescopes blurred the different regions together.

The team then mapped the distribution of about 40 millimeter-wavelength “signatures” from different molecules inside the center of the galaxy. This was critically important since different molecules correspond to different conditions in and around star-forming clouds. For example, carbon monoxide (CO) corresponds to massive envelopes of less dense gas that surround stellar nurseries. Other molecules, like hydrogen cyanide (HCN), reveal dense areas of active star formation. Still rarer molecules, like H13CN and H13CO+, indicate even denser regions.

By comparing the concentration, distribution, and motion of these molecules, the researchers were able to peel apart the star-forming clouds in Sculptor, revealing that they are much more massive, ten times denser, and far more turbulent than similar clouds in quiescent galaxies like the Milky Way.

ALMA image of starbursting clouds inside NGC 253. The red region is the lower density CO gas surrounding higher density star-forming regions in yellow.Credit: B. Saxton (NRAO/AUI/NSF); ALMA (NRAO/ESO/NAOJ), A. Leroy

These stark differences suggest that it’s not just the number of stellar nurseries that sets the throttle for a galaxy to create new stars, but also what kind of stellar nurseries are present. Because the star-forming clouds in Sculptor pack so much material into such a small space, they are simply better at forming stars than the clouds in a galaxy like the Milky Way. Starburst galaxies, therefore, show real physical changes in the star-formation process, not just a one-to-one scaling of star formation with the available reservoir of material.

“These differences have wide-ranging implications for how galaxies grow and evolve,” concluded Leroy. “What we would ultimately like to know is whether a starburst like Sculptor produces not just more stars, but different types of stars than a galaxy like the Milky Way. ALMA is bringing us much closer to that goal.”

These results are accepted for publication in the Astrophysical Journal and are being presented February 15, 2015, at a news conference at the American Association for the Advancement of Science (AAAS) meeting in San Jose, California.

See the full article here.

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 Gains Broadband Connection with Global Science Community”

ALMA

Tuesday, 20 January 2015
Nicolás Lira
Education and Public Outreach Assistant
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 467 6519
Cell: +56 9 9445 7726
Email: nlira@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

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

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

ALMA’s remote location is a boon to astronomy but a telecommunication challenge for the astronomers who work there. Thanks to a newly installed broadband fiber-optic line between the ALMA Operations Site (AOS) and the city of Calama in northern Chile, astronomers from around the world now have high-speed access, 25 times faster than before, to this world-class telescope.

The new system uses 150 kilometers of fiber optic cable to cover the distance from the astronomical observatory to the city of Calama, where it is then linked, through an existing high-speed communication line, to the research and academic network operated by REUNA (Red Universitaria Nacional) in Antofagasta that, thanks to the infrastructure that was developed as part of the EVALSO project, connects to the ALMA offices in Santiago, where the data are processed and shared with astronomers around the world.

“This important milestone for ALMA draws upon the enormous scientific potential of this observatory, by providing an enormous amount of data, with astonishing speed, to the scientific community of the Member States involved in the ALMA observatory and, thereby, reach the world’s scientific community,” said Dr. Eduardo Hardy, representative in Chile for Associated Universities Inc. (AUI).

This important technology and infrastructure milestone for ALMA is the result of a contract signed between AUI, the institution that represents the North American partners of ALMA, with Sílica Networks Chile S.A. and Telefónica Empresas Chile S.A.

“This new infrastructure not only allows transmitting the enormous amount of data generated by ALMA, but it also improves the level of communication between the people operating the observatory at a remote site in the middle of the Atacama Desert and those who process that data in the central offices in Santiago,” said Giorgio Filippi, project leader, who is a staff member of the European Southern Observatory (ESO), that represents the European partners of ALMA.

This project culminated with technical testing of data transmission between the Chajnantor Plateau, situated at an altitude of 5.000 meters above sea level, where ALMA’s 66 antennas are located, and the main offices in Santiago. Although the full capacity of the installed network was not used, two channels with a capacity exceeding 1 Gbps (Gigabite per second) were successfully tested.

“This successful preliminary test confirmed the proper operation of ALMA’s new digital road and opens a number of new possibilities to further enhance the operation of the array and the transmission of scientific data from the observatory,” said Jorge Ibsen, Director of the Computing Department of the Joint ALMA Observatory (JAO).

The new connectivity system is the result of a Memorandum of Understanding signed between the National Radio Astronomy Observatory (NRAO) – operated by AUI – and REUNA. It is planned to become fully operational in the upcoming months once the administrative process is finished.

See the full article here.

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 Universidad de Chile: “Shadows cast by a warp in a planet forming system”

Universidad de Chile

Astronomers from MAD at Universidad de Chile [Millennium ALMA Disk Nucleus] present a viable scenario for the three dimensional geometry of a planet forming system. The finding is based on the discovery of shadows cast by a warped inner disk which bears strong implications for the dynamics of planet formation.

ALMA Array

A piece in the puzzle of how planets form has been unlocked thanks to new insight on planet forming systems. Planets are thought to form in disks of gas and dust that surround new born stars. Assuming that these protoplanetary disks lie in a single plane, all proto-planets tend to be contained in that plane too, much like the planets in our Solar System revolve in coplanar orbits. Interestingly, astronomers at the University of Chile have recognized the existence of shadows in a planet forming system, which require at least two tilted disks.

ALMA image of the protoplanetary disc around HL Tauri – This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system.

NASA/ESA Hubble

Right next to our Solar neighbourhood lies HD142527, a young star surrounded by a large disk rich in gas and dust. This is one of the best studied protoplanetary systems because of its large size, its proximity to us and the variety of ‘planet formation sign posts’ that hint to the presence of newborn planets. As giant planets grow they carve wide trails in the disk along its orbit, leaving rings with less gas and dust that astronomers call gaps. HD142527 exhibits the largest such gap known so far – one could fit three times Neptune’s orbit inside. This gap divides the disk in two distinctive zones: an outer disk (which contains most of the mass) and an inner disk. By comparing different three-dimensional models of the disk with empirical data, astronomers at the Millennium ALMA Disk Nucleus, a.k.a MAD, identified and constrained the geometry of the system. The study was first authored by young scientist Mr. Sebastian Marino, a starting M.Sc. student at U. de Chile.

This image shows a dusty protoplanetary disk around HD142527. The dust and gas are shown in red and green, respectively; near-infrared image taken by the NAOJ Subaru Telescope is shown in blue. The image clearly shows that the dust is concentrated in the upper part of the disk. Image credit: ALMA / ESO / NAOJ / NRAO / Fukagawa et al.

NAOJ/Subaru

This is the star HD142527

Images of the HD142527 disk taken with state-of-the-art instrumentation on large 8 meter-class telescopes, showed two peculiar dark regions, far away from the central star (see above image). These dark regions defied interpretations since they were first seen, in 2011. The new study, published in the Astrophysical Journal Letters, reveals that the inner disk in HD142527 is inclined with respect to the outer disk by about 70 degrees, blocking the star’s light and casting shadows across the gap. The projected shadows coincide with the observed dark regions. The phenomenon is similar to a solar eclipse, in which the Moon blocks the sunlight casting a shadow over Earth, but in this case it is the inner part of the disk what blocks the central star’s light.

Most protoplanetary disks last for only a few million terrestrial years, which is very short compared to the age of planetary systems, making a young disk rich in gas a rather scarce finding. It is during the first few millions of years that giant planets are formed, racing against the quick dispersal and evaporation of the primordial protoplanetary material. The inner disk of HD142527 is about the size of Saturn’s orbit, which means that understanding its evolution could be key to how Earth-like planets form. At the same time, it is very difficult to study these regions since their small sizes on the sky—a millionth of the size of the Moon— and their proximity to the star forbid detailed study with current telescope capabilities. The phenomenon discovered by Marino et al. allows the study of such unreachable regions of planet forming systems, thanks to the shadows cast on larger scales.

The inclined inner disk in HD142527 was inferred using detail 3D modeling of how the star’s light propagates from the central region through the surrounding material, using a technique called “radiative transfer” (see video [below]). But, how does nature produce this configuration? One of the possible explanations requires a companion object, say a planet or a small star, hidden inside the disk. Interestingly, previous studies show evidence for such object. “The astounding fact is that this planet would most likely need to be in a highly inclined orbit, just like the inner parts of the disk. Which poses more interesting questions about the dynamical stability of such arrangement” –says Dr Sebastian Perez, co-author of the research letter.

Warped inner parts of disks have been seen in a variety of astronomical objects, from galaxies to material surrounding black holes. The particular case of HD142527’s shadows may be extended to other protoplanetary disks. “This shadowing may have strong consequences on the physical conditions that lead to planet formation since these regions will be colder and denser than their surroundings, which changes the properties of the primordial gas and dust” –says Dr. Simon Casassus, MAD Principal Investigator.

Although the origin of these warped inner disks is still to be determined, “we now know how to better interpret observations of protoplanetary disks, and what features to look for in other nearby planet forming stars” –says Mr. Sebastián Marino. Protoplanetary disks, which we thought of as peaceful places where planets form, can in fact harbor dramatic dynamics.

See the full article here.

Please help promote STEM in your local schools.

Stem Education Coalition

The University of Chile (Spanish: Universidad de Chile) is the largest and oldest institution of higher education in Chile and one of the oldest in Latin America. Founded in 1842 as the replacement and continuation of the former colonial Royal University of San Felipe (1738) (Spanish: Real Universidad de San Felipe), the university is often called Casa de Bello (House of Bello) in honor of its first president, Andrés Bello. Notable alumni include two Nobel laureates (Pablo Neruda and Gabriela Mistral) and twenty Chilean presidents among many others.

FromDennis Overbye at The New York Times: Birth of a Star

The New York Times

In galactic nurseries like the Orion Nebula, clouds of gas and dust mingle, birthing new stars and planetary systems. The ALMA radio telescope made a recent observation of possible planets being born.

In one of the most detailed astronomical images ever produced, NASA/ESA’s Hubble Space Telescope captured an unprecedented look at the Orion Nebula. … This extensive study took 105 Hubble orbits to complete. All imaging instruments aboard the telescope were used simultaneously to study Orion. The Advanced Camera mosaic covers approximately the apparent angular size of the full moon.

NASA/ESA Hubble

Hubble’s Advanced Camera for Surveys

We might be stardust, Joni Mitchell sang of Woodstock in 1969, echoing what was already a half-century of hard-headed astronomical truth. But astronomers have struggled to understand just exactly how stardust goes from being cosmic smog, littering the lanes of the galaxy, to planets and people.

Recently, however, astronomers using the Atacama Large Millimeter/submillimeter Array, or ALMA, an international radio telescope in the high desert of Chile, obtained what might be the best picture yet of dust in the act of turning into planets.

ALMA Array

It shows a young star named HL Tauri, about 450 light-years from here and thus in the constellation of Taurus. The star is surrounded by a glowing disk of dust and gas about 22 billion miles across — about four times the size of Neptune’s orbit, which bounds the realm of official planets in our own solar system ever since the outlier Pluto was bounced from the fraternity of planets.

HL Tauri

Produced by: Jason Drakeford, Jonathan Corum and Dennis Overbye

Most significant, the disk is scored with dark rings or grooves, like a record or the rings of Saturn.

That, the ALMA astronomers who took the picture say, is most likely the signature of a new planetary system in the making. As clumps of dust accumulate and grow into planets at various distances from the star, they gobble up the dust near them, scouring clear paths around the star and leaving a pattern of bright and dark rings, explained Catherine Vlahakis, an ALMA astronomer.

The ALMA picture represents only the end of the beginning of a long cycle of birth and death for stars and planets.

It begins in galactic nurseries like the Orion nebula, where Christmas-colored clouds of gas and dust mingle primordial elements left over from the Big Bang with the ashes of more recent stars that have died and exploded. Rumbled by explosions and raked by radiation and winds from new stars, the clouds collapse under their own weight.

The result is a cosmic baby boom. Space in Orion is littered with small globs of gas and dust, harboring baby stars and their planets in the making. Stellar tadpoles, if you like, in a cloudy pond.

It can take a million years or so for clouds as massive as the Sun to collapse to the dimensions of a solar system. As they shrink, their centers spin up into swirling maelstroms, protostars surrounded by protoplanetary dust.

If the cloud is big enough, gravity will eventually compress it to the point that it is hot enough to ignite thermonuclear reactions — a star is born and begins to burn its way out of its birth bag.

At the same time, radiation from powerful stars nearby is eating away the cocoon from the outside, setting up a deadly race. Too much radiation from the outside will burn off not only the cocoon but the disk around the new star as well, leaving it naked and alone, without the potential for planets. Luckily that didn’t happen here.

If the disk survives, irregularities in it can grow — first by electrical forces as particles randomly collide and stick, then by gravity as clumps attract one another and sweep their orbits clean like the dark grooves of HL Tauri.

Astronomers estimate that HL Tauri is only a million years old, a blink in the long lifetime of a star. In an email Dr. Vlahakis said that stars this young had not been expected to have planets big enough to gouge grooves in their planetary disks so soon. “This suggests that planet formation might happen faster than previously thought,” she said.

Astronomers have recently estimated that there are at least as many planets in the Milky Way as there are stars. What is happening here has happened billions of times already in the galaxy. The putative planets of HL Tauri have millions or billions of years to make something more of themselves. Life got lucky once in the Milky Way — what are the odds it could happen again?

See the full article here.

Please help promote STEM in your local schools.

Stem Education Coalition

From ALMA: “Antenna dance at ALMA”

ALMA

Tuesday, 23 December 2014
Nicolás Lira
Education and Public Outreach Assistant
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 467 6519
Cell: +56 9 9445 7726
Email: nlira@alma.cl

All of the movements of ALMA’s antennas since September 2009–when the first one arrived at Chajnantor, at an altitude of 5,000 meters in Chile’s Atacama Desert–have been charted in this one-minute, animated film that ALMA has created with the help of INRIA, the Institut National de Recherche en Informatique et en Automatique. “Information about the historical location of each antenna is very important for astronomers when reducing and studying observatory data,” says Denis Barkats, an ALMA astronomer and coauthor of the animated film.

The ALMA antennas are always on the move. One of ALMA’s advantages is its capacity to change the location of the antennas to create different configurations depending on observation needs. The greater the distance between the antennas, the higher the resolution of the images it obtains, although of a smaller portion of the sky. On the other hand, bringing the antennas closer to each other enables the study of larger structures in the sky, albeit with a lower level of detail. ALMA is like a camera’s zoom lens, with the advantage that it can obtain both types of images by moving the antennas.

But transporting the antennas is not a simple matter, as they weigh 100 tons apiece and are high-precision instruments that require very careful handling. That’s why two transporters, Otto and Lore, were designed especially for this purpose. Each transporter has 28 wheels and power equivalent to two Formula 1 engines.

Moving an antenna requires at least six highly trained people and as the animated film shows…this has resulted in a lot of work!

See the full article here.

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: “‘Perfect Storm’ Suffocating Star Formation around a Supermassive Black Hole”

ALMA

Wednesday, 17 December 2014
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

High-energy jets powered by supermassive black holes can blast away a galaxy’s star-forming fuel — resulting in so-called “red and dead” galaxies: those brimming with ancient red stars yet little or no hydrogen gas available to create new ones.

Now astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that black holes don’t have to be nearly so powerful to shut down star formation. By observing the dust and gas at the center NGC 1266, a nearby lenticular galaxy with a relatively modest central black hole, the astronomers have detected a “perfect storm” of turbulence that is squelching star formation in a region that would otherwise be an ideal star factory.

NGC 1266

This turbulence is stirred up by jets from the galaxy’s central black hole slamming into an incredibly dense envelope of gas. This dense region, which may be the result of a recent merger with another smaller galaxy, blocks nearly 98 percent of material propelled by the jets from escaping the galactic center.

“Like an unstoppable force meeting an immovable object, the molecules in these jets meet so much resistance when they hit the surrounding dense gas that they are almost completely stopped in their tracks,” said Katherine Alatalo, an astronomer with the California Institute of Technology in Pasadena and lead author on a paper published in the Astrophysical Journal. This energetic collision produces powerful turbulence in the surrounding gas, disrupting the first critical stage of star formation. “So what we see is the most intense suppression of star formation ever observed,” noted Alatalo.

Previous observations of NGC 1266 revealed a broad outflow of gas from the galactic center traveling up to 400 kilometers per second. Alatalo and her colleagues estimate that this outflow is as forceful as the simultaneous supernova explosion of 10,000 stars. The jets, though powerful enough to stir the gas, are not powerful enough to give it the velocity it needs to escape from the system.

“Another way of looking at it is that the jets are injecting turbulence into the gas, preventing it from settling down, collapsing, and forming stars,” said National Radio Astronomy Observatory astronomer and co-author Mark Lacy.

The region observed by ALMA contains about 400 million times the mass of our Sun in star-forming gas, which is 100 times more than is found in giant star-forming molecular clouds in our own Milky Way. Normally, gas this concentrated should be producing stars at a rate at least 50 times faster than the astronomers observed in this galaxy.

Previously, astronomers believed that only extremely powerful quasars and radio galaxies contained black holes that were powerful enough to serve as a star-forming “on/off” switch.

A combined Hubble Space Telescope / ALMA image of NGC 1266. The ALMA data (orange) are shown in the central region. Credit: NASA/ESA Hubble; ALMA (NRAO/ESO/NAOJ)

NASA/ESA Hubble

“The usual assumption in the past has been that the jets needed to be powerful enough to eject the gas from the galaxy completely in order to be effective at stopping start formation,” said Lacy.

To make this discovery, the astronomers first pinpointed the location of the far-infrared light being emitted by the galaxy. Normally, this light is associated with star formation and enables astronomers to detect regions where new stars are forming. In the case of NGC 1266, however, this light was coming from an extremely confined region of the galaxy. “This very small area was almost too small for the infrared light to be coming from star formation,” noted Alatalo.

With ALMA’s exquisite sensitivity and resolution, and along with observations from CARMA (the Combined Array for Research in Millimeter-wave Astronomy), the astronomers were then able to trace the location of the very dense molecular gas at the galactic center. They found that the gas is surrounding this compact source of the far-infrared light.

CARMA

Under normal conditions, gas this dense would be forming stars at a very high rate. The dust embedded within this gas would then be heated by young stars and seen as a bright and extended source of infrared light. The small size and faintness of the infrared source in this galaxy suggests that NGC 1266 is instead choking on its own fuel, seemingly in defiance of the rules of star formation.

The astronomers also speculate that there is a feedback mechanism at work in this region. Eventually, the black hole will calm down and the turbulence will subside so star-formation can begin anew. With this renewed star formation, however, comes greater motion in the dense gas, which then falls in on the black hole and reestablishes the jets, shutting down star formation once again.

NGC 1266 is located approximately 100 million light-years away in the constellation Eridanus. Leticular galaxies are spiral galaxies, like our own Milky Way, but they have little interstellar gas available to form new stars.

See the full article here.

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 detects Pluto-Size Objects Kicking-up Dust around Sun-Like Star”

ALMA

Thursday, 11 December 2014
Luca Ricci
Harvard-Smithsonian Center for Astrophysics
Email: lucaricci83@gmail.com

Nicolás Lira
Education and Public Outreach Assistant
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 467 6519
Cell: +56 9 9445 7726
Email: nlira@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

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) may have detected the dusty hallmarks of an entire family of Pluto-size objects swarming around an adolescent version of our own Sun.

By making detailed observations of the protoplanetary disk surrounding the star known as HD 107146, the astronomers detected an unexpected increase in the concentration of millimeter-size dust grains in the disk’s outer reaches. This surprising increase, which begins remarkably far — about 13 billion kilometers — from the host star, may be the result of Pluto-size planetesimals stirring up the region, causing smaller objects to collide and blast themselves apart.

ALMA image of the dust surrounding the star HD 107146. Dust in the outer reaches of the disk is thicker than in the inner regions, suggesting that a swarm of Pluto-size planetesimals is causing smaller objects to smash together. The dark ring-like structure in the middle portion of the disk may be evidence of a gap where a planet is sweeping its orbit clear of dust. Credit: L. Ricci ALMA (NRAO/NAOJ/ESO); B. Saxton (NRAO/AUI/NSF).

The new ALMA data also hint at another intriguing feature in the outer reaches of the disk: a possible “dip” or depression in the dust about 1.2 billion kilometer wide, beginning approximately 2.5 times the distance of the Sun to Neptune from the central star. Though only suggested in these preliminary observations, this depression could be a gap in the disk, which would be indicative of an Earth-mass planet sweeping the area clear of debris. Such a feature would have important implications for the possible planet-like inhabitants of this disk and may suggest that Earth-size planets could form in an entirely new range of orbits than have ever been seen before.

“ALMA is critical for the study of these systems that are transitioning from forming planets to having mature planet systems,” said ALMA Deputy Director and coauthor Stuartt Corder. “The material is very tenuous and the combination of sensitivity and resolution offered by ALMA not only makes details in these sorts of objects observable, it makes such observations routine.”

The star HD 107146 is of particular interest to astronomers because it is in many ways a younger version of our own Sun. It also represents a period of transition from a solar system’s early life to its more mature, final stages where planets have finished forming and have settled into their billions-of-years-long orbits around their host star.

“This system offers us the chance to study an intriguing time around a young, Sun-like star,” explained Corder. “We are possibly looking back in time here, back to when the Sun was about two percent of its current age.”

The star HD 107146 is located approximately 90 light-years from Earth in the direction of the constellation Coma Berenices. It is approximately 100 million years old. Further observations with ALMA’s new long baseline, high resolution capabilities will shed more light on the dynamics and composition of this intriguing object. “At longer baselines, we expect to clearly determine the nature of the gap: is it created by a planet or not?” added Corder.

Additional authors on the paper include John M. Carpenter and B. Fu, Caltech; A. M. Hughes, Wesleyan University; and Andrea Isella, Rice University.

See the full article here.

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.