From ALMA: “Chaotically Magnetized Cloud Is No Place to Build a Star, or Is It?”

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

14 June 2017
Nicolás Lira T.
Press Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@alma.cl

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 202 236 6324
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

Artist impression of chaotic magnetic field lines very near a newly emerging protostar. Credit: NRAO/AUI/NSF; D. Berry

For decades, scientists believed that the magnetic field lines around a forming star were extremely powerful and orderly, warping only under extreme force and at great distance from the nascent star.

Now, a team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has discovered a weak and wildly disorganized magnetic field strikingly near a newly emerging protostar. These observations suggest that the impact of magnetic fields on star formation is more complex than previously thought.

The researchers used ALMA to map the surprisingly disorganized magnetic field surrounding a young protostar dubbed Ser-emb 8, which resides about 1400 light-years away in the Serpens star-forming region. These new observations are the most sensitive ever made of the small-scale magnetic field suffusing the region surrounding a young forming star. They also provide important insights into the formation of low-mass stars like own sun.

Previous observations with other telescopes have confirmed that magnetic fields surrounding some young protostars form a classic “hourglass” shape – a hallmark of a strong magnetic field – that starts near the protostar and extends many light-years into the surrounding molecular cloud.

“Before now, we didn’t know if all stars formed in regions that were controlled by strong magnetic fields. Using ALMA, we found our answer,” said Charles L. H. “Chat” Hull, an astronomer and NRAO Jansky Fellow at the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., and lead author on a paper appearing in the Astrophysical Journal Letters. “We can now study magnetic fields in star-forming clouds from the broadest of scales all the way down to the forming star itself. This is exciting because it may mean stars can emerge from a wider range of conditions than we once thought.”

ALMA is able to study magnetic fields at the small scales inside star-forming clumps by mapping the polarization of light emitted by dust grains that have aligned themselves with the magnetic field.

Texture represents the magnetic field orientation in the region surrounding the Ser-emb 8 protostar, as measured by ALMA. The gray region is the millimeter wavelength dust emission. Credit: ALMA (ESO/NAOJ/NRAO); P. Mocz, C. Hull, CfA

By comparing the structure of the magnetic field in the observations with cutting-edge supercomputer simulations on multiple size scales, the astronomers gained important insights into the earliest stages of magnetized star formation. The simulations – which extend from a relatively nearby 140 astronomical units from the protostar (about 4 times the distance from the sun to Pluto) to as far out as 17 light-years – were performed by CfA astronomers Philip Mocz and Blakesley Burkhart, who are coauthors on the paper.

In the case of Ser-emb 8, the astronomers believe they have captured the original magnetic field around the protostar “red handed,” before outflowing material from the star could erase the pristine signature of the magnetic field in the surrounding molecular cloud, noted Mocz.

“Our observations show that the importance of the magnetic field in star formation can vary widely from star to star,” concluded Hull. “This protostar seems to have formed in a weakly magnetized environment dominated by turbulence, while previous observations show sources that clearly formed in strongly magnetized environments. Future studies will reveal how common each scenario is.”

Additional information

This research was presented in a paper titled Unveiling the Role of the Magnetic Field at the Smallest Scales of Star Formation, by C. Hull et al., appearing in the Astrophysical Journal Letters.

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: “Baby Star Spits a ‘Spinning Jet’ As It Munches Down on a ‘Space Hamburger’ “

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

12 June 2017
Dr. Chin-Fei Lee
Institute of Astrophysics and Astronomy
Academia Sinica
Tel: +886-2-2366-5445
Email: cflee@asiaa.sinica.edu.tw

Nicolás Lira T.
Press Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@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

Richard Hook
Public Information Officer, ESO

Garching bei München, Germany

Tel: +49 89 3200 6655

Cell: +49 151 1537 3591
Email: rhook@eso.org

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

Figure 1: Jet and disk in the HH 212 protostellar system: (a) Molecular jet (green image) ejected from the innermost part of the accretion disk (orange image), observed with ALMA at a resolution of 8 au. A dark lane is seen in the disk equator, causing the disk to appear as a “hamburger”. A size scale of our solar system is shown in the lower right corner for size comparison. (b) Split of the redshifted (turning away from us) and blueshifted (turning toward us) emission of the jet in order to show the spinning motion of the jet, as indicated by the green arrows. Blue and red arrows show the rotation of the disk, which has a direction the same as the jet rotation. Credit: ALMA (ESO/NAOJ/NRAO)/Lee et al.

Protostellar jets are seen coming out from protostars (baby stars), representing one of the most intriguing signposts of star formation. An international research team, led by Chin-Fei Lee in Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, Taiwan), has made a new breakthrough observation with the Atacama Large Millimeter/submillimeter Array (ALMA), finding a protostellar jet to be spinning, convincingly for the first time. This new result confirms the expected role of the jet in removing the excess angular momentum from the innermost region of an accretion disk (space hamburger), providing a solution to the long-standing problem of how the inner accretion disk can feed a protostar.

“We see jets coming out from most of baby stars, like a train of bullets speeding down along the rotational axis of the accretion disks. We always wonder what their role is. Are they spinning, as expected in current models of jet launching? However, since the jets are very narrow and their spinning motion is very small, we had not been able to confirm their spinning motion. Now using the ALMA with its unprecedented combination of spatial and velocity resolutions, we not only resolve a jet near a protostar down to 10 astronomical units (au) but also detect its spinning motion”, says Chin-Fei Lee at ASIAA. “It looks like a baby star spits a spinning bullet each time it takes a bite of a space hamburger.”

“The central problem in forming a star is the angular momentum in the accretion disk which prevents material from falling into the central protostar. Now with the jet carrying away the excess angular momentum from the material in the innermost region of the disk, the material can readily fall into the central protostar from the disk”, says Paul Ho at ASIAA.

HH 212 is a nearby protostellar system in Orion at about 1300 lightyears. The central protostar is very young with an age of only 40,000 years (which is about 10 millionth of the age of the Sun) and a mass of only a fifth of the Sun. Recent ALMA observations at submillimeter wavelength have detected an accretion disk feeding the central protostar. The disk is nearly edge-on and has a radius of about 60 au. Interestingly, it shows a prominent equatorial dark lane sandwiched between two brighter features, appearing as a “space hamburger”.

Figure 2: A 3D cartoon showing a spinning jet coming out from an accretion disk that feeds the central protostar. (Left) The jet is spinning (as shown by the green arrows), with the blue part turning toward us and the red part turning away from us. In the disk, the blue color is cooler than the orange color. (Right) A zoom-in to the innermost region, showing the possible disk accretion and jet launching processes near the protostar. Our results imply that the jet is launched at about 0.05 au, as shown by the green arrows. The jet carries away the excess angular momentum, allowing the disk material there to fall into the central protostar, as shown by the blue arrows. As in current jet models, the jet is hollow and higher resolution is needed to check it. Credit: Lee, C.-F.

The central protostar drives a powerful bipolar jet. Previous observations at a spatial resolution of 140 au could not confirm a rotation for the jet. Now with ALMA at a resolution of 8 au, which is about 17 times higher, we zoom in to the innermost part of the jet down to within 10 au of the central protostar and find a jet rotation. The angular momentum is so small that the jet must be launched from the innermost region of the disk at about 0.05 au from the central protostar, well consistent with current models of the jet launching.

Credit: Lee, C.-F.

This new finding indicates that the jet indeed carries away part of the angular momentum (rotational momentum) from the material in the innermost region of the accretion disk (space hamburger), which is rotating around the central protostar. This reduces the rotation of the material there, allowing the disk to feed the central protostar.

These observations open an exciting possibility of detecting and measuring jet rotation around the protostars through high-resolution imaging with ALMA, which provides strong constraints on theories of jet formation in star formation. In addition, these observations also open the possibility of detecting jet rotation in other kind of objects, e.g., active nuclei of galaxies, which may play the same role of extracting disk angular momentum as the protostellar jets.

Additional information

ALMA also clearly imaged the rotation of a gas outflow from a massive protostar. (Press release ALMA Hears Birth Cry of a Massive Baby Star).

This research was presented in a paper A Rotating Protostellar Jet Launched from the Innermost Disk of HH 212, by Lee et al. to appear in the journal Nature Astronomy.

The team is composed of Chin-Fei Lee (ASIAA, Taiwan; National Taiwan University, Taiwan), Paul T.P. Ho (ASIAA, Taiwan; East Asia Observatory), Zhi-Yun Li (University of Virginia, USA), Naomi Hirano (ASIAA, Taiwan), Qizhou Zhang (Harvard-Smithsonian Center for Astrophysics, USA), and Hsien Shang (ASIAA, Taiwan).

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 Observes Birth Cry of a Massive Baby Star”

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

12 June 2017
Nicolás Lira T.
Press Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@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

Richard Hook
Public Information Officer, ESO

Garching bei München, Germany

Tel: +49 89 3200 6655

Cell: +49 151 1537 3591
Email: rhook@eso.org

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

Figure 3. The rotation of the outflow from Orion KL Source I imaged with ALMA. The color shows the motion of the gas; red shows gas moving away from us, whereas blue shows gas moving toward us. The disk is shown in white. Credit: ALMA (ESO/NAOJ/NRAO), Hirota et al.

An international research team used the Atacama Large Millimeter/submillimeter Array (ALMA) to determine how the enigmatic gas flow from a massive baby star is launched. The astronomers observed the baby star and obtained clear evidence of rotation in the outflow. The motion and the shape of the outflow indicate that the interplay of centrifugal and magnetic forces in a disk surrounding the star plays a crucial role in the star’s birth cry.

Stars form from gas and dust floating in interstellar space. But, astronomers do not yet fully understand how it is possible to form the massive stars seen in space. One key issue is gas rotation. The parent cloud rotates slowly in the initial stage and the rotation becomes faster as the cloud shrinks due to self-gravity. Stars formed in such a process should have very rapid rotation, but this is not the case. The stars observed in the Universe rotate more slowly.

How is the rotational momentum dissipated? One possible scenario involves that the gas emanating from baby stars. If the gas outflow rotates, it can carry rotational momentum away from the system. Astronomers have tried to detect the rotation of the outflow to test this scenario and understand its launching mechanism. In a few cases signatures of rotation have been found, but it has been difficult to resolve clearly, especially around massive baby stars.

Figure 1. Artist’s impression of Orion KL Source I. The massive protostar is surrounded by a disk of gas and dust. The outflow is launched from the surface of the outer disk. Credit: ALMA (ESO/NAOJ/NRAO)

The team of astronomers led by Tomoya Hirota, an assistant professor at the National Astronomical Observatory of Japan (NAOJ) and SOKENDAI (the Graduate University for Advanced Studies) observed a massive baby star called Orion KL Source I in the famous Orion Nebula, located 1,400 light-years away from the Earth. The Orion Nebula is the closest massive-star forming region to Earth. Thanks to its close vicinity and ALMA’s advanced capabilities, the team could reveal the nature of the outflow from Source I.

“We have clearly imaged the rotation of the outflow,” said Hirota, the lead author of the research paper published in the journal Nature Astronomy. “In addition, the result gives us important insight into the launching mechanism of the outflow.”

The new ALMA observations beautifully illustrate the rotation of the outflow, in the same direction as the gas disk surrounding the star. This strongly supports the idea that the outflow plays an important role in dissipating the rotational energy.

Figure 2. Orion KL Source I observed with ALMA. The massive protostar is in the center and surrounded by a gas disk (red). A bipolar gas outflow is ejected from the protostar (blue). Credit: ALMA (ESO/NAOJ/NRAO), Hirota et al.

Furthermore, ALMA clearly shows that the outflow is launched not from the vicinity of the baby star itself, but rather from the outer edge of the disk. This morphology agrees well with the “magnetocentrifugal disk wind model.” In this model, gas in the rotating disk moves outward due to the centrifugal force and then moves upward along the magnetic field lines to form outflows. Although previous observations with ALMA have found supporting evidence around a low-mass protostar, there was little compelling evidence around massive protostars because most of the massive-star forming regions are rather distant and difficult to investigate in detail.

“In addition to high sensitivity and fidelity, high resolution submillimeter-wave observation is essential to our study, which ALMA made possible for the first time. Submillimeter waves are a unique diagnostic tool for the dense innermost region of the outflow, and at that exact place we detected the rotation,” explained Hirota. “ALMA’s resolution will become even higher in the future. We would like to observe other objects to improve our understanding of the launching mechanism of outflows and the formation scenario of massive stars with the assistance of theoretical research.”

Additional information

ALMA also imaged rotation of a gas jet from a low-mass protostar. Please read the press release Baby Star Spits a ‘Spinning Jet’ As It Munches -Down on a ‘Space Hamburger’ from the Academia Sinica Institute of Astronomy and Astrophysics, Taiwan.

These observation results were published as Hirota et al. Disk-Driven Rotating Bipolar Outflow in Orion Source I in Nature Astronomy on June 12, 2017.

The research team members are:

Tomoya Hirota (National Astronomical Observatory of Japan / SOKENDAI), Masahiro Machida (Kyushu University), Yuko Matsushita (Kyushu University), Kazuhito Motogi (Yamaguchi University / NAOJ), Naoko Matsumoto (Yamaguchi University / NAOJ), Mi Kyoung Kim (Korean Astronomy and Space Science Institute), Ross A. Burns (Joint Institute for VLBI ERIC), Mareki Honma (NAOJ/SOKENDAI)

This research was supported by Grants-in-Aid from the Japan Society for the Promotion of Science and the Ministry of Education, Culture, Sports, Science and Technology, Japan (No. 21224002、 24684011、25108005、15H03646、15K17613、24540242、25120007).

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 Finds Ingredient of Life Around Infant Sun-like Stars”

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

8 June 2017
Rafael Martín-Doménech
Centro de Astrobiología
Madrid, Spain
Email: rmartin@cab.inta-csic.es

Victor Rivilla
INAF-Osservatorio Astrofisico di Arcetri
Italy
Email: rivilla@arcetri.astro.it

Audrey Coutens
Laboratoire d’Astrophysique de Bordeaux
France
Email: audrey.coutens@u-bordeaux.fr

Niels Ligterink
Sackler Laboratory for Astrophysics, Leiden Observatory
Netherlands
Tel: +31 (0) 71 527 5844
Email: ligterink@strw.leidenuniv.nl

Nicolás Lira T.
Press Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@alma.cl

Richard Hook
Public Information Officer, ESO

Garching bei München, Germany

Tel: +49 89 3200 6655

Cell: +49 151 1537 3591
Email: rhook@eso.org

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 202 236 6324
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

ALMA has observed stars like the Sun at a very early stage in their formation and found traces of methyl isocyanate — a chemical building block of life. This is the first ever detection of this prebiotic molecule towards solar-type protostars, the sort from which our Solar System evolved. The discovery could help astronomers understand how life arose on Earth.

Two teams of astronomers have harnessed the power of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to detect the prebiotic complex organic molecule methyl isocyanate [1] in the multiple star system IRAS 16293-2422. One team was co-led by Rafael Martín-Doménech at the Centro de Astrobiología in Madrid, Spain, and Víctor M. Rivilla, at the INAF-Osservatorio Astrofisico di Arcetri in Florence, Italy; and the other by Niels Ligterink at the Leiden Observatory in the Netherlands and Audrey Coutens at University College London, United Kingdom.

“This star system seems to keep on giving! Following the discovery of sugars, we’ve now found methyl isocyanate. This family of organic molecules is involved in the synthesis of peptides and amino acids, which, in the form of proteins, are the biological basis for life as we know it,” explain Niels Ligterink and Audrey Coutens [2].

ALMA’s capabilities allowed both teams to observe the molecule at several different and characteristic wavelengths across the radio spectrum [3]. They found the unique chemical fingerprints located in the warm, dense inner regions of the cocoon of dust and gas surrounding young stars in their earliest stages of evolution. Each team identified and isolated the signatures of the complex organic molecule methyl isocyanate [4]. They then followed this up with computer chemical modelling and laboratory experiments to refine our understanding of the molecule’s origin [5].

IRAS 16293-2422 is a multiple system of very young stars, around 400 light-years away in a large star-forming region called Rho Ophiuchi in the constellation of Ophiuchus (The Serpent Bearer). The new results from ALMA show that methyl isocyanate gas surrounds each of these young stars.

The Rho Ophiuchi star formation region in the constellation of Ophiuchus

Earth and the other planets in our Solar System formed from the material left over after the formation of the Sun. Studying solar-type protostars can therefore open a window to the past for astronomers and allow them to observe conditions similar to those that led to the formation of our Solar System over 4.5 billion years ago.

Rafael Martín-Doménech and Víctor M. Rivilla, lead authors of one of the papers, comment: “We are particularly excited about the result because these protostars are very similar to the Sun at the beginning of its lifetime, with the sort of conditions that are well suited for Earth-sized planets to form. By finding prebiotic molecules in this study, we may now have another piece of the puzzle in understanding how life came about on our planet.”

Niels Ligterink is delighted with the supporting laboratory results: “Besides detecting molecules we also want to understand how they are formed. Our laboratory experiments show that methyl isocyanate can indeed be produced on icy particles under very cold conditions that are similar to those in interstellar space This implies that this molecule — and thus the basis for peptide bonds — is indeed likely to be present near most new young solar-type stars.”

Notes

[1] A complex organic molecule is defined in astrochemistry as consisting of six or more atoms, where at least one of the atoms is carbon. Methyl isocyanate contains carbon, hydrogen, nitrogen and oxygen atoms in the chemical configuration CH3NCO. This very toxic substance was the main cause of death following the tragic Bhopal industrial accident in 1984.

[2] The system was previously studied by ALMA in 2012 and found to contain molecules of the simple sugar glycolaldehyde, another ingredient for life.

[3] The team led by Rafael Martín-Doménech used new and archive data of the protostar taken across a large range of wavelengths across ALMA’s receiver Bands 3, 4 and 6. Niels Ligterink and his colleagues used data from the ALMA Protostellar Interferometric Line Survey (PILS), which aims to chart the chemical complexity of IRAS 16293-2422 by imaging the full wavelength range covered by ALMA’s Band 7 on very small scales, equivalent to the size of our Solar System.

[4] The teams carried out spectrographic analysis of the protostar’s light to determine the chemical constituents. The amount of methyl isocyanate they detected — the abundance — with respect to molecular hydrogen and other tracers is comparable to previous detections around two high-mass protostars (i.e. within the massive hot molecular cores of Orion KL and Sagittarius B2 North).

[5] Martín-Doménech’s team chemically modelled gas-grain formation of methyl isocyanate. The observed amount of the molecule could be explained by chemistry on the surface of dust grains in space, followed by chemical reactions in the gas phase. Moreover, Ligterink’s team demonstrated that the molecule can be formed at extremely cold interstellar temperatures, down to 15 Kelvin (–258 degrees Celsius), using cryogenic ultra-high-vacuum experiments in their laboratory in Leiden.

More information

This research was presented in two papers: First Detection of Methyl Isocyanate (CH3NCO) in a solar-type Protostar by R. Martín-Doménech et al. and The ALMA-PILS survey: Detection of CH3NCO toward the low-mass protostar IRAS 16293-2422 and laboratory constraints on its formation, by N. F. W. Ligterink et al.. Both papers will appear in the same issue of the Monthly Notices of the Royal Astronomical Society.

One team is composed of: R. Martín-Doménech (Centro de Astrobiología, Spain), V. M. Rivilla (INAF-Osservatorio Astrofisico di Arcetri, Italy), I. Jiménez-Serra (Queen Mary University of London, UK), D. Quénard (Queen Mary University of London, UK), L. Testi (INAF-Osservatorio Astrofisico di Arcetri, Italy; ESO, Garching, Germany; Excellence Cluster “Universe”, Germany) and J. Martín-Pintado (Centro de Astrobiología, Spain).

The other team is composed of: N. F. W. Ligterink (Sackler Laboratory for Astrophysics, Leiden Observatory, the Netherlands), A. Coutens (University College London, UK), V. Kofman (Sackler Laboratory for Astrophysics, The Netherlands), H. S. P. Müller (Universität zu Köln, Germany), R. T. Garrod (University of Virginia, USA), H. Calcutt (Niels Bohr Institute & Natural History Museum, Denmark), S. F. Wampfler (Center for Space and Habitability, Switzerland), J. K. Jørgensen (Niels Bohr Institute & Natural History Museum, Denmark), H. Linnartz (Sackler Laboratory for Astrophysics, The Netherlands) and E. F. van Dishoeck (Leiden Observatory, The Netherlands; Max-Planck-Institut für Extraterrestrische Physik, Germany).

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

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

See the full ALMA article here .
See the full ESO 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 Returns to Boomerang Nebula”

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

05 June 2017
Nicolás Lira T.
Press Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@alma.cl

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 202 236 6324
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

Composite image of the Boomerang Nebula, a pre-planetary nebula produced by a dying star. ALMA observations (orange) showing the hourglass-shaped outflow, which is embedded inside a roughly round ultra-cold outflow. The hourglass outflow stretches more than three trillion kilometers from end to end (about 21,000 times the distance from the Sun to the Earth), and is the result of a jet that is being fired by the central star, sweeping up the inner regions of the ultra-cold outflow like a snow-plow. The ultra-cold outflow is about 10 times bigger. The ALMA data are shown on top of an image from the Hubble Space Telescope (blue). Credit: ALMA (ESO/NAOJ/NRAO); NASA/ESA Hubble; NRAO/AUI/NSF

NASA/ESA Hubble Telescope

An ancient red giant star in the throes of a frigid death has produced the coldest known object in the cosmos — the Boomerang Nebula. How this star could create an environment strikingly colder than the natural background temperature of deep space has been a compelling mystery for more than two decades.

The answer, according to astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), may be that a small companion star has plunged into the heart of the red giant, ejecting most the matter of the larger star as an ultra-cold outflow of gas and dust.

This outflow is expanding so rapidly — about 10 times faster than a single star could produce on its own — that its temperature has fallen to less than half a degree Kelvin (minus 458.5 degrees Fahrenheit). Zero degrees Kelvin is known as absolute zero, the point at which all thermodynamic motion stops.

The ALMA observations enabled the researchers to unravel this mystery by providing the first precise calculations of the nebula’s extent, age, mass, and kinetic energy.

“These new data show us that most of the stellar envelope from the massive red giant star has been blasted out into space at speeds far beyond the capabilities of a single, red giant star,” said Raghvendra Sahai, an astronomer at NASA’s Jet Propulsion Laboratory in Pasadena, California, and lead author on a paper appearing in the Astrophysical Journal. “The only way to eject so much mass and at such extreme speeds is from the gravitational energy of two interacting stars, which would explain the puzzling properties of the ultra-cold outflow.” Such close companions may be responsible for the early and violent demise of most stars in the Universe, Sahai noted.

“The extreme properties of the Boomerang challenge the conventional ideas about such interactions and provide us with one of the best opportunities to test the physics of binary systems that contain a giant star,” adds Wouter Vlemmings, an astronomer at Chalmers University of Technology in Sweden and co-author on the study.

The Boomerang Nebula is located about 5,000 light-years from Earth in the constellation Centaurus. The red giant star at its center is expected to shrink and get hotter, ultimately ionizing the gas around it to produce a planetary nebula. Planetary nebulae are dazzling objects created when stars like our sun (or a few times bigger) shed their outer layers as an expanding shell near the end of their nuclear-fusion-powered life. The Boomerang Nebula represents the very early stages of this process, a so-called pre-planetary nebula.

When the Boomerang Nebula was first observed in 1995, astronomers noted that it was absorbing the light of the Cosmic Microwave Background, which is the leftover radiation from the Big Bang. This radiation provides the natural background temperature of space — only 2.725 degrees above absolute zero. For the Boomerang Nebula to absorb that radiation, it had to be even colder than this lingering, dim energy that has been continually cooling for more than 13 billion years.

The new ALMA observations also produced an evocative image of this pre-planetary nebula, showing an hourglass-shaped outflow inside a roughly round ultra-cold outflow. The hourglass outflow stretches more than three trillion kilometers from end to end (about 21,000 times the distance from the Sun to the Earth), and is the result of a jet that is being fired by the central star, sweeping up the inner regions of the ultra-cold outflow like a snowplow.

The ultra-cold outflow is more than 10 times bigger. Traveling at 164 kilometers per second, it took material at its outer edges approximately 3,500 years to reach these extreme distances after it was first ejected from the dying star.

These conditions, however, will not last long. Even now, the Boomerang Nebula is slowly warming.

“We see this remarkable object at a very special, very short-lived period of its life,” noted Lars-Åke Nyman, an astronomer at the Joint ALMA Observatory in Santiago, Chile, and co-author on the paper. “It’s possible these super cosmic freezers are quite common in the Universe, but they can only maintain such extreme temperatures for a relatively short time.”

See the full article here .

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

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

From ALMA: “ALMA Eyes Icy Ring Around Young Planetary System”

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

18 May 2017
Nicolás Lira T.
Press Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@alma.cl

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 202 236 6324
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

Composite image of the Fomalhaut star system. The ALMA data, shown in orange, reveal the distant and eccentric debris disk in never-before-seen detail. The central dot is the unresolved emission from the star, which is about twice the mass of the Sun. Optical data from the Hubble Space Telescope is in blue; the dark region is a coronagraphic mask, which filtered out the otherwise overwhelming light of the central star. Credit: ALMA (ESO/NAOJ/NRAO), M. MacGregor; NASA/ESA Hubble, P. Kalas; B. Saxton (NRAO/AUI/NSF)

NASA/ESA Hubble Telescope

An international team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has made the first complete millimeter-wavelength image of the ring of dusty debris surrounding the young star Fomalhaut. This remarkably well-defined band of rubble and gas is likely the result of exocomets smashing together near the outer edges of a planetary system 25 light-years from Earth. Observations Suggest Chemical Kinship to Comets in Our Own Solar System.

Earlier ALMA observations of Fomalhaut — taken in 2012 when the telescope was still under construction – revealed only about one half of the debris disk.

Though this first image was merely a test of ALMA’s initial capabilities, it nonetheless provided tantalizing hints about the nature and possible origin of the disk.

The new ALMA observations offer a stunningly complete view of this glowing band of debris and suggest that there are chemical similarities between its icy contents and comets in our own solar system.

“ALMA has given us this staggeringly clear image of a fully formed debris disk,” said Meredith MacGregor, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, USA, and lead author on one of two papers accepted for publication in the Astrophysical Journal describing these observations. “We can finally see the well-defined shape of the disk, which may tell us a great deal about the underlying planetary system responsible for its highly distinctive appearance.”

Fomalhaut is a relatively nearby star system and one of only about 20 in which planets have been imaged directly. The entire system is approximately 440 million years old, or about one-tenth the age of our solar system.

As revealed in the new ALMA image, a brilliant band of icy dust about 2 billion kilometers wide has formed approximately 20 billion kilometers from the star.

Debris disks are common features around young stars and represent a very dynamic and chaotic period in the history of a solar system. Astronomers believe they are formed by the ongoing collisions of comets and other planetesimals in the outer reaches of a recently formed planetary system. The leftover debris from these collisions absorbs light from its central star and reradiates that energy as a faint millimeter-wavelength glow that can be studied with ALMA.

Using the new ALMA data and detailed computer modeling, the researchers could calculate the precise location, width, and geometry of the disk. These parameters confirm that such a narrow ring is likely produced through the gravitational influence of planets in the system, noted MacGregor.

The new ALMA observations are also the first to definitively show “apocenter glow,” a phenomenon predicted in a 2016 paper by lead author Margaret Pan, a scientist at the Massachusetts Institute of Technology in Cambridge and co-author on the new ALMA papers. Like all objects with elongated orbits, the dusty material in the Fomalhaut disk travels more slowly when it is farthest from the star. As the dust slows down, it piles up, forming denser concentrations in the more distant portions of the disk. These dense regions can be seen by ALMA as brighter millimeter-wavelength emission.

ALMA image of the debris disk in the Fomalhaut star system. The ring is approximately 20 billion kilometers from the central star and it is about 2 billion kilometers wide. The central dot is the unresolved emission from the star, which is about twice the mass of the Sun. Credit: ALMA (ESO/NAOJ/NRAO); M. MacGregor

Using the same ALMA dataset, but focusing on distinct millimeter-wavelength signals naturally emitted by molecules in space, the researchers also detected vast stores of carbon monoxide gas in precisely the same location as the debris disk.

“These data allowed us to determine that the relative abundance of carbon monoxide plus carbon dioxide around Fomalhaut is about the same as found in comets in our own solar system,” said Luca Matrà with the University of Cambridge, UK, and lead author on the team’s second paper. “This chemical kinship may indicate a similarity in comet formation conditions between the outer reaches of this planetary system and our own.” Matrà and his colleagues believe this gas is either released from continuous comet collisions or the result of a single, large impact between supercomets hundreds of times more massive than Hale-Bopp.

The presence of this well-defined debris disk around Fomalhaut, along with its curiously familiar chemistry, may indicate that this system is undergoing its own version of the Late Heavy Bombardment, a period approximately 4 billion years ago when the Earth and other planets were routinely struck by swarms of asteroids and comets left over from the formation of the Solar System.

“Twenty years ago, the best millimeter-wavelength telescopes gave the first fuzzy maps of sand grains orbiting Fomalhaut. Now with ALMA’s full capabilities the entire ring of material has been imaged,” concluded Paul Kalas, an astronomer at the University of California at Berkeley and principal investigator on these observations. “One day we hope to detect the planets that influence the orbits of these grains.”

Additional information

This research is presented in a paper titled A complete ALMA map of the Fomalhaut debris disk, M. MacGregor, et al., appearing in the Astrophysical Journal, and Detection of exocometary CO within the 440MYR-old Fomalhaut belt: A similar CO+CO2 ice abundance in exocomets and solar system comets, L. Matrà et al., appearing in the Astrophysical Journal.

This work benefited from: NASA’s Nexus for Exoplanet System Science (NExSS) research coordination network sponsored by NASA’s Science Mission Directorate, NASA grants NNX15AC89G, NNX15AD95G, NSF grant AST-1518332, NSF Graduate Research Fellowship DGE1144152, and from NRAO Student Observing Support. This work has also been possible thanks to an STFC postgraduate studentship and the European Union through ERC grant number 279973.

See the full article here .

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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: “APEX Extension Agreement Signed”

European Southern Observatory

12 May 2017
Peter Grimley
pgrimley@partner.eso.org
ESO Assistant Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6383

APEX. ESO

An extension of the agreement between the partners of the Atacama Pathfinder Experiment (APEX) has been signed, ensuring that this very productive collaboration will continue until the end of 2022. The 12-metre APEX telescope saw first light in 2005 and has provided astronomers with detailed views of the coldest objects and processes in the Universe.

APEX is a collaborative effort between the Max-Planck-Institute for Radio Astronomy (MPIfR) in Bonn, Germany, ESO and the Onsala Space Observatory (OSO) in Onsala, Sweden, and the agreement was signed by ESO’s Director General, Tim de Zeeuw, Karl Menten, Director at the Max-Planck-Institut für Radioastronomie and John Conway, Director of the Onsala Space Observatory. The ceremony took place at Chalmers University of Technology in Gothenburg, Sweden.

Under the APEX extension agreement, the telescope will be upgraded to significantly improve the overall observing efficiency, and the suite of instruments will be upgraded to a new generation. These new instruments include several prototype receivers for ALMA, opening up new atmospheric windows (eso1543) and increasing the bandwidth of existing receivers. In order to better accommodate the high demand for APEX from the ESO community, ESO’s share will increase from 27% to 32%. The MPIfR share will also increase from 50% to 55%, while the OSO share will decrease from 23% to 13%.

APEX is designed to work at sub-millimetre wavelengths between infrared light and radio waves, from 0.2 to 1.9 millimetres, which is key to revealing some of the coldest material in the Universe. Over the years, it has shed light on a wide range of astronomical phenomena. It has probed the wild early lives of today’s most massive galaxies (eso1206), studied matter torn apart by a supermassive black hole (eso0841), and mapped the plane of the Milky Way at submillimetre wavelengths (eso1606). It also detected molecules of hydrogen peroxide in interstellar space for the first time (eso1123), solved a centuries-old mystery of a stellar collision (eso1511), and — in conjunction with other telescopes around the world — observed the heart of a distant quasar, producing images two million times sharper than human vision (eso1229).

Because sub-millimetre radiation from space is heavily absorbed by water vapour in the Earth’s atmosphere, APEX is located at an altitude of 5100 metres on the Chajnantor plateau in Chile’s Atacama Desert, one of the driest places on Earth, where unsurpassed observing opportunities are available.

As its name implies, APEX is the pathfinder to the ALMA project.

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

It is a modified ALMA prototype antenna and shares the site of the ALMA observatory, which is itself now fully operational as the world’s largest ground-based facility for observations in the millimetre/submillimetre regime. ALMA comprises a giant array of fifty-four 12-metre antennas and twelve 7-metre antennas, which — thanks to the pioneering efforts of APEX — enables transformational research into the physics of the cold Universe, probing the first stars and galaxies, and directly imaging the formation of planets. Several of APEX’s strengths, such as its capability to map very wide areas, are highly complementary to ALMA.

With the extension of the agreement to 2022, the European user community will continue to benefit from this privileged opportunity to optimally prepare for ALMA follow-up programmes and APEX will continue to probe the cold and distant Universe, undoubtedly contributing further exciting discoveries.

More Information

APEX is a collaboration between the Max-Planck-Institut für Radioastronomie (MPIfR), Onsala Space Observatory (OSO), and the European Southern Observatory (ESO). The telescope was designed and constructed by VERTEX Antennentechnik GmbH (Germany), under contract to MPIfR, and is based on a prototype antenna constructed for the ALMA project. Operation of APEX in Chile is entrusted to ESO.

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ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

ESO/Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres

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

ESO/Vista Telescope at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

ESO/NTT at Cerro LaSilla 600 km north of Santiago de Chile at an altitude of 2400 metres

VLT Survey Telescope at Cerro Paranal with an elevation of 2,635 metres (8,645 ft) above sea level

ALMA on the Chajnantor plateau at 5,000 metres

ESO/E-ELT to be built at Cerro Armazones at 3,060 m

APEX Atacama Pathfinder 5,100 meters above sea level, at the Llano de Chajnantor Observatory in the Atacama desert

From AAS NOVA: ” An Exploration of Dusty Galaxies”

American Astronomical Society

21 April 2017
Susanna Kohler

A small section of the UKIDSS Ultra Deep Survey field. A new study of 53 submillimeter galaxies in this field reveals more about galaxies in our early universe. [University of Nottingham/Omar Almaini]

Submillimeter galaxies — i.e., galaxies that we detect in the submillimeter wavelength range — are mysterious creatures. It’s only within the last couple decades that we’ve had telescope technology capable of observing them, and we’re only now getting to the point where angular resolution limits allow us to examine them closely. A new study has taken advantage of new capabilities to explore the properties of a sample of 52 of these galaxies.

Dusty Star Formation

Submillimeter galaxies are generally observed in the early universe. Though they’re faint in other wavebands, they’re extremely luminous in infrared and submillimeter — their infrared luminosities are typically trillions of times the Sun’s luminosity. This is thought to be because these galaxies are very actively forming stars at rates of hundreds of times that of the Milky Way!

Example 10” × 10” true-color images of ten submillimeter galaxies in the authors’ ALMA-identified sample. [Simpson et al. 2017]

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

Submillimeter galaxies are also extremely dusty, so we don’t see their star formation directly in optical wavelengths. Instead, we see the stellar light after it’s been absorbed and reemitted by interstellar dust lanes — we’re indirectly observing heavily obscured star formation.

Why look for submillimeter galaxies? Studying them can help us to learn about galaxy and star formation early in our universe’s history, and help us to understand how the universe has evolved into what we see locally today.

Submillimeter Struggles

Due to angular resolution limitations in the past, we often couldn’t pin down the exact locations of submillimeter galaxies, preventing us from examining them properly. But now a team of scientists has used the Atacama Large Millimeter/submillimeter array (ALMA) to precisely locate 52 submillimeter galaxies identified by the Submillimeter Common-User Bolometer Array (SCUBA-2) in the UKIDSS Ultra Deep Survey field.

East Asia Observatory James Clerk Maxwell telescope, Mauna Kea, Hawaii, USA

The precise locations made possible by ALMA allowed the team — led by James Simpson (University of Edinburgh and Durham University) — to identify the multi-wavelength properties of these galaxies in a pilot study that they hope to extend to many more similar galaxies in the future.

Photometric redshift distribution of the ALMA-identified submillimeter galaxies in the authors’ sample (grey). [Simpson et al. 2017]

Lessons from Distant Galaxies

What did Simpson and collaborators learn in this study?

1. For the set of galaxies for which the team could measure photometric redshifts, the median redshift was z ~ 2.65 (though redshifts ranged up to z ~ 5).
2. Submillimeter galaxies are cooler and larger than local far-infrared galaxies (known as ULIRGs). The authors therefore argue that it’s unlikely that ULIRGs are evolved versions of submillimeter galaxies.
3. Estimates of dust mass in these galaxies suggest that effectively all of the optical-to-near-infrared light from colocated stars is obscured by dust.
4. Estimates of the future stellar mass of these galaxies suggest that they cannot evolve into lenticular or spiral galaxies. Instead, the authors conclude, submillimeter galaxies must be the progenitors of local elliptical galaxies.

Citation

J. M. Simpson et al 2017 ApJ 839 58. doi:10.3847/1538-4357/aa65d0

Related Journal Articles

The scuba-2 cosmology legacy survey: alma resolves the rest-frame far-infrared emission of sub-millimeter galaxies doi: 10.1088/0004-637X/799/1/81
The scuba-2 cosmology legacy survey: alma resolves the bright-end of the sub-millimeter number counts doi: 10.1088/0004-637X/807/2/128
An alma survey of submillimeter galaxies in the extended chandra deep field south: the redshift distribution and evolution of submillimeter galaxies doi: 10.1088/0004-637X/788/2/125
The scuba-2 cosmology legacy survey: multiwavelength counterparts to 103 submillimeter galaxies in the ukidss-uds field doi: 10.3847/0004-637X/820/2/82
The scuba-2 cosmology legacy survey: ultraluminous star-forming galaxies in a z = 1.6 cluster doi: 10.1088/0004-637X/782/1/19
Extremely red submillimeter galaxies: new z ≳ 4–6 candidates discovered using alma and jansky vla doi: 10.3847/1538-4357/835/2/286

NRAO/VLA, on the Plains of San Agustin fifty miles west of Socorro, NM, USA

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From ALMA: “ALMA Investigates ‘DeeDee,’ a Distant, Dim Member of Our Solar System”

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

April 12, 2017
Nicolás Lira T.
Press Coordinator
Joint ALMA Observatory
Santiago, Chile
Tel: +56 2 24 67 65 19
Cell: +56 9 94 45 77 26
Email: nicolas.lira@alma.cl

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory
Charlottesville, Virginia, USA
Tel: +1 434 296 0314
Cell: +1 202 236 6324
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

Artist concept of the planetary body 2014 UZ224, more informally known as DeeDee. ALMA was able to observe the faint millimeter-wavelength “glow” emitted by the object, confirming it is roughly 635 kilometers across. At this size, DeeDee should have enough mass to be spherical, the criterion necessary for astronomers to consider it a dwarf planet, though it has yet to receive that official designation. Credit: Alexandra Angelich (NRAO/AUI/NSF)

Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have revealed extraordinary details about a recently discovered far-flung member of our solar system, the planetary body 2014 UZ224, more informally known as DeeDee.

ALMA image of the faint millimeter-wavelength “glow” from the planetary body 2014 UZ224, more informally known as DeeDee. At three times the distance of Pluto from the Sun, DeeDee is the second most distant known TNO with a confirmed orbit in our solar system. Credit: ALMA (ESO/NAOJ/NRAO)

At about three times the current distance of Pluto from the Sun, DeeDee is the second most distant known trans-Neptunian object (TNO) with a confirmed orbit, surpassed only by the dwarf planet Eris. Astronomers estimate that there are tens-of-thousands of these icy bodies in the outer solar system beyond the orbit of Neptune.

The new ALMA data reveal, for the first time, that DeeDee is roughly 635 kilometers across, or about two-thirds the diameter of the dwarf planet Ceres, the largest member of our asteroid belt. At this size, DeeDee should have enough mass to be spherical, the criterion necessary for astronomers to consider it a dwarf planet, though it has yet to receive that official designation.

“Far beyond Pluto is a region surprisingly rich with planetary bodies. Some are quite small but others have sizes to rival Pluto, and could possibly be much larger,” said David Gerdes, a scientist with the University of Michigan and lead author on a paper appearing in the Astrophysical Journal Letters. “Because these objects are so distant and dim, it’s incredibly difficult to even detect them, let alone study them in any detail. ALMA, however, has unique capabilities that enabled us to learn exciting details about these distant worlds.”

Currently, DeeDee is about 92 astronomical units (AU) from the Sun. An astronomical unit is the average distance from the Earth to the Sun, or about 150 million kilometers. At this tremendous distance, it takes DeeDee more than 1,100 years to complete one orbit. Light from DeeDee takes nearly 13 hours to reach Earth.

Gerdes and his team announced the discovery of DeeDee in the fall of 2016. They found it using the 4-meter Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile as part of ongoing observations for the Dark Energy Survey, an optical survey of about 12 percent of the sky that seeks to understand the as-yet mysterious force that is accelerating the expansion of the universe.

The Dark Energy Survey produces vast troves of astronomical images, which give astronomers the opportunity to also search for distant solar system objects.

The initial search, which includes nearly 15,000 images, identified more than 1.1 billion candidate objects. The vast majority of these turned out to be background stars and even more distant galaxies. A small fraction, however, were observed to move slowly across the sky over successive observations, the telltale sign of a TNO.

One such object was identified on 12 separate images. The astronomers informally dubbed it DeeDee, which is short for Distant Dwarf.

The optical data from the Blanco telescope enabled the astronomers to measure DeeDee’s distance and orbital properties, but they were unable to determine its size or other physical characteristics. It was possible that DeeDee was a relatively small member of our solar system, yet reflective enough to be detected from Earth. Or, it could be uncommonly large and dark, reflecting only a tiny portion of the feeble sunlight that reaches it; both scenarios would produce identical optical data.

Since ALMA observes the cold, dark universe, it is able to detect the heat – in the form of millimeter-wavelength light – emitted naturally by cold objects in space. The heat signature from a distant solar system object would be directly proportional to its size.

“We calculated that this object would be incredibly cold, only about 30 degrees Kelvin, just a little above absolute zero,” said Gerdes.

While the reflected visible light from DeeDee is only about as bright as a candle seen halfway the distance to the moon, ALMA was able to quickly home in on the planetary body’s heat signature and measure its brightness in millimeter-wavelength light.

This allowed astronomers to determine that it reflects only about 13 percent of the sunlight that hits it. That is about the same reflectivity of the dry dirt found on a baseball infield.

By comparing these ALMA observations to the earlier optical data, the astronomers had the information necessary to calculate the object’s size. “ALMA picked it up fairly easily,” said Gerdes. “We were then able to resolve the ambiguity we had with the optical data alone.”

Objects like DeeDee are cosmic leftovers from the formation of the solar system. Their orbits and physical properties reveal important details about the formation of planets, including Earth.

This discovery is also exciting because it shows that it is possible to detect very distant, slowly moving objects in our own solar system. The researchers note that these same techniques could be used to detect the hypothesized “Planet Nine” that may reside far beyond DeeDee and Eris.

“There are still new worlds to discover in our own cosmic backyard,” concludes Gerdes. “The solar system is a rich and complicated place.”

Orbits of objects in our solar system, showing the current location of the planetary body ‘DeeDee’.
Credit: Alexandra Angelich (NRAO/AUI/NSF)

Additional information

This research is presented in a paper titled “Discovery and physical characterization of a large scattered disk object at 92 AU,” appearing in the Astrophysical Journal Letters.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

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

See the full article here .

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The NRAO operates a complementary, state-of-the-art suite of radio telescope facilities for use by the scientific community, regardless of institutional or national affiliation: the Very Large Array (VLA), the Robert C. Byrd Green Bank Telescope (GBT), and the Very Long Baseline Array (VLBA)*.

NRAO ALMA

Green Bank Observatory radio telescope, Green Bank, West Virginia, USA, formerly supported by NSF, but now on its own

NRAO VLA

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From ALMA: “ALMA Captures Explosive Star Birth”

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

07 April 2017
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Stellar explosions are most often associated with supernovae, the spectacular deaths of stars. But new ALMA observations of the Orion Nebula complex provide insights into explosions at the other end of the stellar life cycle, star birth. Astronomers captured these dramatic images of the remains of a 500-year-old explosion as they explored the firework-like debris from the birth of a group of massive stars, demonstrating that star formation can be a violent and explosive process too. The colours in the ALMA data represent the relative Doppler shifting of the millimetre-wavelength light emitted by carbon monoxide gas. The blue colour in the ALMA data represents gas approaching at the highest speeds; the red colour is from gas moving toward us more slowly. The background image includes optical and near-infrared imaging from both the Gemini South and ESO Very Large Telescope. The famous Trapezium Cluster of hot young stars appears towards the bottom of this image. The ALMA data do not cover the full image shown here. Credit: ALMA (ESO/NAOJ/NRAO), J. Bally/H. Drass et al.

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.

Photo taken by Rogelio Bernal Andreo in October 2010 of the Orion constellation showing the surrounding nebulas of the Orion Molecular Cloud complex. Also captured is the red supergiant Betelgeuse (top left) and the famous belt of Orion composed of the OB stars Altitak, Alnilam and Mintaka. To the bottom right can be found the star Rigel. The red crescent shape is Barnard’s Loop. The photograph appeared as the Astronomy Picture of the Day on October 23, 2010.
Date 23 August 2012
Source http://deepskycolors.com/astro/JPEG/RBA_Orion_HeadToToes.jpg

Star birth can be a violent and explosive event, as dramatically illustrated in new ALMA images.

Around 500 years ago, a pair of adolescent protostars had a perilously close encounter that blasted their stellar nursery apart.

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have examined the widely scattered debris from this explosive event, gaining new insights into the sometimes-fierce relationship among sibling stars.

Shortly after starting to form some 100,000 years ago, several protostars in the Orion Molecular Cloud 1 (OMC-1), a dense and active star factory about 1,500 light-years from Earth just behind the Orion Nebula, latched onto each other gravitationally and gradually drew closer.

Eventually, two of these stars either grazed each other or collided, triggering a powerful eruption that launched other nearby protostars and hundreds of giant streamers of dust and gas into interstellar space at speeds greater than 150 kilometers per second. This cataclysmic interaction released as much energy as our Sun emits over the course of 10 million years.

Today, the remains of this spectacular explosion are visible from Earth.

Credit: ALMA (ESO/NAOJ/NRAO), J. Bally

“What we see in this once calm stellar nursery is a cosmic version of a fireworks display, with giant streamers rocketing off in all directions,” said John Bally with the University of Colorado and lead author on a paper published in the Astrophysical Journal.

Stellar explosions are most often associated with supernovae, the spectacular deaths of stars. But new ALMA observations of the Orion Nebula complex provide insights into explosions at the other end of the stellar life cycle, star birth. Astronomers captured these dramatic images of the remains of a 500-year-old explosion as they explored the firework-like debris from the birth of a group of massive stars, demonstrating that star formation can be a violent and explosive process too. The colours in the ALMA data represent the relative Doppler shifting of the millimetre-wavelength light emitted by carbon monoxide gas. The blue colour in the ALMA data represents gas approaching at the highest speeds; the red colour is from gas moving toward us more slowly. The background is an infrared image from the HAWK-I camera on ESO’s Very Large Telescope. The ALMA data only cover the region marked by the box. Credit:ALMA (ESO/NAOJ/NRAO), J. Bally/H. Drass et al.

ESO/VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

ESO HAWK-I

Groups of stars such as those in OMC-1 are born when a cloud of gas hundreds of times more massive than our Sun begins to collapse under its own gravity. In the densest regions, protostars form and begin to drift about randomly. Over time, this random motion can dampen, which allows some of the stars to fall toward a common center of gravity, usually dominated by a particularly large protostar.

If these stars draw too close to each other before they drift away into the galaxy, violent interactions can occur. According to the researchers, such explosions are expected to be relatively short lived, with the remnants like those seen by ALMA lasting only centuries.

“Though fleeting, protostellar explosions may be relatively common,” said Bally. “By destroying their parent cloud, as we see in OMC-1, such explosions may also help to regulate the pace of star formation in these giant molecular clouds.”

Bally and his team observed this feature previously with the Gemini-South telescope in Chile.

Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile

These earlier images, taken in the near infrared, reveal the remarkable structure of the streamers, which extend nearly a light-year from end to end.

Hints of the explosive nature of this outflow were first uncovered in 2009 with the Submillimeter Array in Hawaii.

CfA Submillimeter Array Mauna Kea, Hawaii, USA

The new ALMA data, however, provide much greater clarity, unveiling important details about the distribution and high-velocity motion of the carbon monoxide (CO) gas inside the streamers. This helps astronomers understand the underlying force of the blast and the impact such events could have on star formation across the galaxy.

“People most often associate stellar explosions with ancient stars, like a nova eruption on the surface of a decaying star or the even more spectacular supernova death of an extremely massive star,” Bally says. “ALMA has given us new insights into explosions on the other end of the stellar life cycle, star birth.”

See the full article here .

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

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