Space Butterfly' Is Home to Hundreds of Baby Stars

Officially known as W40, this red butterfly in space is a nebula, or a giant cloud of gas and dust. The "wings" of the butterfly are giant bubbles of gas being blown from the inside out by massive stars. Credit: NASA/JPL-Caltech.  › Full image and caption

What looks like a red butterfly in space is in reality a nursery for hundreds of baby stars, revealed in this infrared image from NASA's Spitzer Space Telescope. Officially named Westerhout 40 (W40), the butterfly is a nebula - a giant cloud of gas and dust in space where new stars may form. The butterfly's two "wings" are giant bubbles of hot, interstellar gas blowing from the hottest, most massive stars in this region.

Besides being beautiful, W40 exemplifies how the formation of stars results in the destruction of the very clouds that helped create them. Inside giant clouds of gas and dust in space, the force of gravity pulls material together into dense clumps. Sometimes these clumps reach a critical density that allows stars to form at their cores. Radiation and winds coming from the most massive stars in those clouds - combined with the material spewed into space when those stars eventually explode - sometimes form bubbles like those in W40. But these processes also disperse the gas and dust, breaking up dense clumps and reducing or halting new star formation. 

The material that forms W40's wings was ejected from a dense cluster of stars that lies between the wings in the image. The hottest, most massive of these stars, W40 IRS 1a, lies near the center of the star cluster. W40 is about 1,400 light-years from the Sun, about the same distance as the well-known Orion nebula, although the two are almost 180 degrees apart in the sky. They are two of the nearest regions in which massive stars - with masses upwards of 10 times that of the Sun - have been observed to be forming.

Another cluster of stars, named Serpens South, can be seen to the upper right of W40 in this image. Although both Serpens South and the cluster at the heart of W40 are young in astronomical terms (less than a few million years old), Serpens South is the younger of the two. Its stars are still embedded within their cloud but will someday break out to produce bubbles like those of W40. Spitzer has also produced a more detailed image of the Serpens South cluster. 

A mosaic of Spitzer's observation of the W40 star-forming region was originally published as part of the Massive Young stellar clusters Study in Infrared and X-rays (MYStIX) survey of young stellar objects. 

The Spitzer picture is composed of four images taken with the telescope's Infrared Array Camera (IRAC) during Spitzer's prime mission, in different wavelengths of infrared light: 3.6, 4.5, 5.8 and 8.0 ?m (shown as blue, green, orange and red). Organic molecules made of carbon and hydrogen, called polycyclic aromatic hydrocarbons (PAHs), are excited by interstellar radiation and become luminescent at wavelengths near 8.0 microns, giving the nebula its reddish features. Stars are brighter at the shorter wavelengths, giving them a blue tint. Some of the youngest stars are surrounded by dusty disks of material, which glow with a yellow or red hue.

The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

More information on Spitzer can be found at its website:  http://www.spitzer.caltech.edu/

News Media Contact

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

Source: JPL-Caltech/Images

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Simulating nature’s cosmic laboratory, one helium droplet at a time

Schematic representation of the new method: Two reactants R1 and R2 are added to a helium droplet. The energy released in the resulting reaction decreases the droplet’s size. The decrease in size can be measured, and allows researchers to deduct the reaction energy. Image: Krasnokutskiy / MPIA

Two astronomers from the Max Planck Institute for Astronomy and from the University of Jena have found an elegant new method to measure the energy of simple chemical reactions, under similar conditions as those encountered by atoms and molecules in the early solar system. Their method promises accurate measurements of reaction energies that can be used to understand chemical reactions under space conditions – in cluding those reactions that were responsible of creating organic chemicals as the raw material for the development of life.

In order for life to form, nature needed plenty raw materials in the shape of complex organic molecules. Some of those molecules are likely to have formed long before, in space, during the birth of the Solar System. Systematic studies of the necessary chemical reactions, which take place on the craggy and convoluted surfaces of dust grains, were and are hampered by a lack of data. Which elementary reactions, involving which individual reactants are possible? What temperature is required for a reaction to take place? Which molecules are produced in those reactions? Now, Thomas Henning, director at the Max Planck Institute for Astronomy (MPIA), and Sergiy Krasnokutskiy of the MPIA’s Laboratory Astrophysics Group at the University of Jena have developed an elegant method to study such elementary surface reactions – using minute liquid helium droplets.

In the early solar system, long before the formation of Earth, complex chemical reaction took place, creating substantial amounts of organic molecules. The cosmic laboratory for these works of chemical synthesis was provided by grains of dust – clusters of mostly silicates and carbon, covered with a mantle of ice, with complicated and delicate tendrils and ramifications, and on this basis with one crucial property: A comparatively large surface on which chemical reactions could take place. In the millions of years that follows, many of those dust grains would cluster together for form ever larger structures, until finally, solid planets emerged, orbiting the young Sun.

Creating the raw ingredients for life

While all of the organic compounds synthesized on the grain surfaces would be destroyed by the unavoidable heat during planet formation, some of the molecules remained in waiting, encapsulated in, or clinging to the surface of, smallish grains or lumps of rock, as well as in the icy bodies of the comets. By one account of the history of life, once Earth’s surface had cooled sufficiently for liquid water to form, it was these grains and rocks, hitting Earth’s surface in the shape of meteorites, some of them landing in warm, small, ponds, that provided the chemical basis for life to form on our home planet.

In order to understand the early natural chemical experiments in our universe, we need to know the properties of the various reactions. For instance, do certain reactions need a specific activation energy to happen? What is the eventual product of a given reaction? Those parameters determine which reactions can happen under what conditions in the early Solar system, and they are key for any realistic reconstruction of early Solar system chemistry.

Scarce data about low-temperature surface reactions

Yet precise data on these reactions is surprisingly scarce. Instead, a substantial part of chemical research is dedicated to the study of such reactions in the gaseous phase, with the atoms and molecules floating freely, colliding, and forming compounds. But the crucial chemical reactions in space needed to build up larger organic molecules take place under markedly different conditions – on the surfaces of dust grains. This changes even the basic physics of the situation: When a new molecule is formed, the energy of the chemical bond formation is stored in the newly created molecule. If this energy is not passed on to the environment, the new molecule will quickly be destroyed. This prevents the formation of many species of in the gas phase. On a surface, or in a medium, where energy can readily be absorbed by the additional matter present, the conditions for certain types of reactions building complex molecules, step by step, are much more favorable.

Henning and Krasnokutskiy developed an elegant method for measuring the energetics of such reactions. Their mock-ups of cosmic laboratories are miniature helium droplets, a few nanometers in size, drifting in a high vacuum. The reactants – that is, the atoms or molecules meant to take part in the reaction – are brought into the vacuum chamber as gases, but in such minute amounts that helium droplets are overwhelmingly likely to pick up either a single molecule of each required species or none, but not more. The helium droplets act as a medium that, similar to the surface of a dust grain, can absorb reaction energy, allowing reactions to happen under similar conditions to those in the early Solar system. This reproduces a key feature of the relevant surface chemistry (although other properties, such as catalytic properties of a specific dust surface, are not modelled).

Nanodrops as measuring devices

Furthermore, the two astronomers used the helium nanodrops as energy measuring devices (calorimeters). As reaction energy is released into the drop, some of the Helium atoms will evaporate in a predictable fashion. The remaining drop is now smaller than before – a difference in size that can be measured using two alternative methods: an electron beam (a larger drop is easier to hit than a smaller one!) or a precise measurement of the pressure in the vacuum chamber created by Helium droplets hitting the wall, where larger droplets produce greater pressure. By calibrating their method using reactions that had been studied in detail beforehand, and whose properties are well-known, the two astronomers were able to increase the method’s accuracy considerably. All in all, the new method provides an elegant new way of investigating the formation pathway of complex organic molecules in space. This should enable researchers to be more specific about the raw materials nature had to work with in the run-up of the emergence of life on Earth. But there is more:

The first measurements using the new technique confirm a trend that had already been visible in other recent experiments: On surfaces, at low temperatures, carbon atoms are surprisingly reactive. The researchers found a surprisingly high number – almost a dozen – of reactions involving carbon atoms which are barrierless, that is, which do not require extra energy input to proceed, and hence can occur at very low temperatures. Evidently, the condensation of atomic gas at low temperatures is bound to lead to the formation of a large variety of organic molecules. But that large possible variety also means that molecules of each specific species will be very rare.

This, in turn, suggests that astronomers might be drastically underestimating the amount of organic molecules in outer space. When it comes to estimating abundances, astronomical observations examine the trace signatures (spectral lines) of each molecular species separately. If there are many different species of organic molecules out there, each separate species can “fly under the radar.” Its molecules might be present only in amounts too minute for astronomers to detect, and in addition, even the tell-tale signatures of the molecules (more generally those of specific functional groups common to different types of molecules) could be slightly altered, making the molecule evade detection. But added up, it is possible that all these separate species of molecule together could make up a substantial amount of matter in outer space – a hidden outer-space world of organic chemistry.

Background information

The results presented here have been published as Henning, Th. & S. A. Krasnokutski 2019, “Experimental Characterization of the Energetics of Low-temperature Surface Reactions” in the journal Nature Astronomy.

Journal article

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Science contact

Sergiy Krasnokutskiy
Email: sergiy.krasnokutskiy@uni-jena.de

PR contact

Markus Pössel
Public Information Officer
Phone:+49 6221 528-261
Email: pr@mpia.de

Source: Max Planck Institute for Astronomy/Science Releases

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GRAVITY instrument breaks new ground in exoplanet imaging

PR Image eso1905a

GRAVITY instrument breaks new ground in exoplanet imaging 

PR Image eso1905b

HR 8799 in the constellation Pegasus

PR Image eso1905c

Surroundings of the star HR 8799 

PR Image eso1905d

Aerial view of the VLTI with tunnels superimposed 

PR Image eso1905e

VLT interferometer principle

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Videos

PR Video eso1905a

ESOcast 197 Light: GRAVITY uncovers stormy exoplanet skies

PR Video eso1905b

Orbital motion of the HR8799 system

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Cutting-edge VLTI instrument reveals details of a storm-wracked exoplanet using optical interferometry

The GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) has made the first direct observation of an exoplanet using optical interferometry. This method revealed a complex exoplanetary atmosphere with clouds of iron and silicates swirling in a planet-wide storm. The technique presents unique possibilities for characterising many of the exoplanets known today.

This result was announced today in a letter in the journal Astronomy and Astrophysics by the GRAVITY Collaboration [1], in which they present observations of the exoplanet HR8799e using optical interferometry. The exoplanet was discovered in 2010 orbiting the young main-sequence star HR8799, which lies around 129 light-years from Earth in the constellation of Pegasus.

Today’s result, which reveals new characteristics of HR8799e, required an instrument with very high resolution and sensitivity. GRAVITY can use ESO’s VLT’s four unit telescopes to work together to mimic a single larger telescope using a technique known as interferometry [2]. This creates a super-telescope — the VLTI  — that collects and precisely disentangles the light from HR8799e’s atmosphere and the light from its parent star [3].

HR8799e is a ‘super-Jupiter’, a world unlike any found in our Solar System, that is both more massive and much younger than any planet orbiting the Sun. At only 30 million years old, this baby exoplanet is young enough to give scientists a window onto the formation of planets and planetary systems. The exoplanet is thoroughly inhospitable — leftover energy from its formation and a powerful greenhouse effect heat HR8799e to a hostile temperature of roughly 1000 °C.

This is the first time that optical interferometry has been used to reveal details of an exoplanet, and the new technique furnished an exquisitely detailed spectrum of unprecedented quality — ten times more detailed than earlier observations. The team’s measurements were able to reveal the composition of HR8799e’s atmosphere  — which contained some surprises.

“Our analysis showed that HR8799e has an atmosphere containing far more carbon monoxide than methane — something not expected from equilibrium chemistry,” explains team leader Sylvestre Lacour researcher CNRS at the Observatoire de Paris - PSL and the Max Planck Institute for Extraterrestrial Physics. “We can best explain this surprising result with high vertical winds within the atmosphere preventing the carbon monoxide from reacting with hydrogen to form methane.”

The team found that the atmosphere also contains clouds of iron and silicate dust. When combined with the excess of carbon monoxide, this suggests that HR8799e’s atmosphere is engaged in an enormous and violent storm.

“Our observations suggest a ball of gas illuminated from the interior, with rays of warm light swirling through stormy patches of dark clouds,” elaborates Lacour. “Convection moves around the clouds of silicate and iron particles, which disaggregate and rain down into the interior. This paints a picture of a dynamic atmosphere of a giant exoplanet at birth, undergoing complex physical and chemical processes.”

This result builds on GRAVITY’s string of impressive discoveries, which have included breakthroughs such as last year’s observation of gas swirling at 30% of the speed of light just outside the event horizon of the massive Black Hole in the Galactic Centre. It also adds a new way of observing exoplanets to the already extensive arsenal of methods available to ESO’s telescopes and instruments — paving the way to many more impressive discoveries [4].

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Notes

[1] GRAVITY was developed by a collaboration consisting of the Max Planck Institute for Extraterrestrial Physics (Germany), LESIA of Paris Observatory–PSL / CNRS / Sorbonne Université / Univ. Paris Diderot and IPAG of Université Grenoble Alpes / CNRS (France), the Max Planck Institute for Astronomy (Germany), the University of Cologne (Germany), the CENTRA–Centro de Astrofisica e Gravitação (Portugal) and ESO.

[2] Interferometry is a technique that allows astronomers to create a super-telescope by combining several smaller telescopes. ESO’s VLTI is an interferometric telescope created by combining two or more of the Unit Telescopes (UTs) of the Very Large Telescope or all four of the smaller Auxiliary Telescopes. While each UT has an impressive 8.2-m primary mirror, combining them creates a telescope with 25 times more resolving power than a single UT observing in isolation.

[3] Exoplanets can be observed using many different methods. Some are indirect, such as the radial velocity method used by ESO’s exoplanet-hunting HARPS instrument, which measures the pull a planet’s gravity has on its parent star. Direct methods, like the technique pioneered for this result, involve observing the planet itself instead of its effect on its parent star.

[4] Recent exoplanet discoveries made using ESO telescopes include last year’s successful detection of a super-Earth orbiting Barnard’s Star, the closest single star to our Sun, and ALMA’s discovery of young planets orbiting an infant star, which used another novel technique for planet detection.

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More Information

This research was presented in the paper “First direct detection of an exoplanet by optical interferometry” in Astronomy and Astrophysics.

The team was composed of :  S. Lacour (LESIA, Observatoire de Paris - PSL, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Meudon, France [LESIA]; Max Planck Institute for Extraterrestrial Physics, Garching, Germany [MPE]), M. Nowak (LESIA), J. Wang (Department of Astronomy, California Institute of Technology, Pasadena, USA), O. Pfuhl (MPE), F. Eisenhauer (MPE), R. Abuter (ESO, Garching, Germany), A. Amorim (Universidade de Lisboa, Lisbon, Portugal; CENTRA - Centro de Astrofísica e Gravitação, IST, Universidade de Lisboa, Lisbon, Portugal), N. Anugu (Faculdade de Engenharia, Universidade do Porto, Porto, Portugal; School of Physics, Astrophysics Group, University of Exeter, Exeter, United Kingdom), M. Benisty (Univ. Grenoble Alpes, CNRS, IPAG, Grenoble, France [IPAG]), J.P. Berger (IPAG), H. Beust (IPAG), N. Blind (Observatoire de Genève, Université de Genève, Versoix, Switzerland), M. Bonnefoy (IPAG), H. Bonnet (ESO, Garching, Germany), P. Bourget (ESO, Santiago, Chile), W. Brandner (Max Planck Institute for Astronomy, Heidelberg, Germany [MPIA]), A. Buron (MPE), C. Collin (LESIA), B. Charnay (LESIA), F. Chapron (LESIA) , Y. Clénet (LESIA), V. Coudé du Foresto (LESIA), P.T. de Zeeuw (MPE; Sterrewacht Leiden, Leiden University, Leiden, The Netherlands), C. Deen (MPE), R. Dembet (LESIA), J. Dexter (MPE), G. Duvert (IPAG), A. Eckart (1st Institute of Physics, University of Cologne, Cologne, Germany;  Max Planck Institute for Radio Astronomy, Bonn, Germany), N.M. Förster Schreiber (MPE), P. Fédou (LESIA), P. Garcia (Faculdade de Engenharia, Universidade do Porto, Porto, Portugal; ESO, Santiago, Chile; CENTRA - Centro de Astrofísica e Gravitação, IST, Universidade de Lisboa, Lisbon, Portugal), R. Garcia Lopez (Dublin Institute for Advanced Studies, Dublin, Ireland; MPIA), F. Gao (MPE), E. Gendron (LESIA), R. Genzel (MPE; Departments of Physics and Astronomy, University of California, Berkeley, USA), S. Gillessen (MPE), P. Gordo (Universidade de Lisboa, Lisbon, Portugal; CENTRA - Centro de Astrofísica e Gravitação, IST, Universidade de Lisboa, Lisbon, Portugal), A. Greenbaum (Department of Astronomy, University of Michigan, Ann Arbor, USA), M. Habibi (MPE), X. Haubois (ESO, Santiago, Chile), F. Haußmann (MPE), Th. Henning (MPIA), S. Hippler (MPIA), M. Horrobin (1st Institute of Physics, University of Cologne, Cologne, Germany), Z. Hubert (LESIA), A. Jimenez Rosales (MPE), L. Jocou (IPAG), S. Kendrew (European Space Agency, Space Telescope Science Institute, Baltimore, USA; MPIA), P. Kervella (LESIA), J. Kolb (ESO, Santiago, Chile), A.-M. Lagrange (IPAG), V. Lapeyrère (LESIA), J.-B. Le Bouquin (IPAG), P. Léna (LESIA), M. Lippa (MPE), R. Lenzen (MPIA), A.-L. Maire (STAR Institute, Université de Liège, Liège, Belgium; MPIA), P. Mollière (Sterrewacht Leiden, Leiden University, Leiden, The Netherlands), T. Ott (MPE), T. Paumard (LESIA), K. Perraut (IPAG), G. Perrin (LESIA), L. Pueyo (Space Telescope Science Institute, Baltimore, USA), S. Rabien (MPE), A. Ramírez (ESO, Santiago, Chile), C. Rau (MPE), G. Rodríguez-Coira (LESIA), G. Rousset (LESIA), J. Sanchez-Bermudez (Instituto de Astronomía, Universidad Nacional Autónoma de México, Mexico City, Mexico; MPIA), S. Scheithauer (MPIA), N. Schuhler (ESO, Santiago, Chile), O. Straub (LESIA; MPE), C. Straubmeier (1st Institute of Physics, University of Cologne, Cologne, Germany), E. Sturm (MPE), L.J. Tacconi (MPE), F. Vincent (LESIA), E.F. van Dishoeck (MPE; Sterrewacht Leiden, Leiden University, Leiden, The Netherlands), S. von Fellenberg (MPE), I. Wank (1st Institute of Physics, University of Cologne, Cologne, Germany), I. Waisberg (MPE) , F. Widmann (MPE), E. Wieprecht (MPE), M. Wiest (1st Institute of Physics, University of Cologne, Cologne, Germany), E. Wiezorrek (MPE), J. Woillez (ESO, Garching, Germany), S. Yazici (MPE; 1st Institute of Physics, University of Cologne, Cologne, Germany), D. Ziegler (LESIA), and G. Zins (ESO, Santiago, Chile).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 16 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a Strategic Partner. 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 and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.

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Links

• Research paper 
• Photos of GRAVITY
• Photos of the VLT

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Contacts

Sylvestre Lacour
CNRS/LESIA, Observatoire de Paris - PSL
5 place Jules Janssen, Meudon, France
Tel: +33 6 81 92 53 89
Email: Sylvestre.lacour@observatoiredeparis.psl.eu

Mathias Nowak
CNRS/LESIA, Observatoire de Paris - PSL
5 place Jules Janssen, Meudon, France
Tel: +33 1 45 07 76 70
Cell: +33 6 76 02 14 48
Email: Mathias.nowak@observatoiredeparis.psl.eu

Dr. Paul Mollière
Sterrewacht Leiden, Huygens Laboratory
Leiden, The Netherlands
Tel: +31 64 2729185
Email: molliere@strw.leidenuniv.nl

Calum Turner
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6670
Email: pio@eso.org

Source: ESO/News

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Ultra-sharp Images Make Old Stars Look Absolutely Marvelous!

Figure 1. Color composite GSAOI+GeMS image of HP 1 obtained using the Gemini South telescope in Chile. North is up and East to the left. Composite image produced by Mattia Libralato of the Space Telescope Science Institute. Credit: Gemini Observatory/AURA/NSF; composite image produced by Mattia Libralato of Space Telescope Science Institute.  Full resolution PNG

Figure 2. . GSAOI+GeMS color composite image of HP 1 (right image) shown relative to the full field of the cluster obtained by the Visible and Infrared Survey Telescope for Astronomy (left). Credit: Gemini Observatory/NSF/AURA/VISTA/Aladin/CDS.  Full resolution JPG

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Using high-resolution adaptive optics imaging from the Gemini Observatory, astronomers have uncovered one of the oldest star clusters in the Milky Way Galaxy. The remarkably sharp image looks back into the early history of our Universe and sheds new insights on how our Galaxy formed.

Just as high-definition imaging is transforming home entertainment, it is also advancing the way astronomers study the Universe.

“Ultra-sharp adaptive optics images from the Gemini Observatory allowed us to determine the ages of some of the oldest stars in our Galaxy,” said Leandro Kerber of the Universidade de São Paulo and Universidade Estadual de Santa Cruz, Brazil. Kerber led a large international research team that published their results in the April 2019 issue of the Monthly Notices of the Royal Astronomical Society.

Using advanced adaptive optics technology at the Gemini South telescope in Chile, the researchers zoomed in on a cluster of stars known as HP 1. “Removing our atmosphere’s distortions to starlight with adaptive optics reveals tremendous details in the objects we study,” added Kerber. “Because we captured these stars in such great detail, we were able to determine their advanced age and piece together a very compelling story.”

That story begins just as the Universe was reaching its one-billionth birthday.

"This star cluster is like an ancient fossil buried deep in our Galaxy's bulge, and now we've been able to date it to a far-off time when the Universe was very young,” said Stefano Souza, a PhD student at the Universidade de São Paulo, Brazil, who worked with Kerber as part of the research team. The team’s results date the cluster at about 12.8 billion years, making these stars among the oldest ever found in our Galaxy. “These are also some of the oldest stars we’ve seen anywhere,” added Souza.

“HP 1 is one of the surviving members of the fundamental building blocks that assembled our Galaxy’s inner bulge,” said Kerber. Until a few years ago, astronomers believed that the oldest globular star clusters — spherical swarms of up to a million stars — were only located in the outer parts of the Milky Way, while the younger ones resided in the innermost Galactic regions. However, Kerber’s study, as well as other recent work based on data from the Gemini Observatory and the Hubble Space Telescope (HST), have revealed that ancient star clusters are also found within the Galactic bulge and relatively close to the Galactic center.

Globular clusters tell us much about the formation and evolution of the Milky Way. Most of these ancient and massive stellar systems are thought to have coalesced out of the primordial gas cloud that later collapsed to form the spiral disk of our Galaxy, while others appear to be the cores of dwarf galaxies consumed by our Milky Way. Of the roughly 160 globular clusters known in our Galaxy, about a quarter are located within the greatly obscured and tightly packed central bulge region of the Milky Way. This spherical mass of stars some 10,000 light years across forms the central hub of the Milky Way (the yolk if you will) which is made primarily of old stars, gas, and dust. Among the clusters within the bulge, those that are the most metal-poor (lacking in heavier elements) – which includes HP 1 – have long been suspected of being the oldest. HP 1 then is pivotal, as it serves as an excellent tracer of our Galaxy’s early chemical evolution.

“HP 1 is playing a critical role in our understanding of how the Milky Way formed,” Kerber said. “It is helping us to bridge the gap in our understanding between our Galaxy's past and its present.”

Kerber and his international team used the exquisitely deep high-resolution adaptive optics images from Gemini Observatory as well as archival optical images from the HST to identify faint cluster members, which are essential for age determination. With this rich data set they confirmed that HP 1 is a fossil relic born less than a billion years after the Big Bang, when the Universe was in its infancy.

"These results crown an effort of more than two decades with some of the world's premier telescopes aimed at determining accurate chemical abundances with high-resolution spectroscopy," said Beatriz Barbuy of the Universidade de São Paulo, coauthor of this paper and a world-renowned expert in this field. "These Gemini images are the best ground-based photometric data we have. They are at the same level of HST data, allowing us to recover a missing piece in our puzzle: the age of HP 1. From the existence of such old objects, we can attest to the short star formation timescale in the Galactic bulge, as well as its fast chemical enrichment."

To determine the cluster’s distance, the team used archival ground-based data to identify 11 RR Lyrae variable stars (a type of “standard candle” used to measure cosmic distances) within HP 1. The observed brightness of these RR Lyrae stars indicate that HP 1 is at a distance of about 21,500 light years, placing it approximately 6,000 light years from the Galactic center, well within the Galaxy’s central bulge region.

Kerber and his team also used the Gemini data, as well HST, Very Large Telescope, and Gaia mission data, to refine the orbit of HP 1 within our Galaxy. This analysis shows that during HP 1’s history, the cluster came as close as about 400 light years from the Galactic center – less than one-tenth of its current distance.

“The combination of high angular resolution and near-infrared sensitivity makes GeMS/GSAOI an extremely powerful tool for studying these compact, highly dust-enshrouded stellar clusters,” added Mattia Libralato of the Space Telescope Science Institute, a coauthor on the study. “Careful characterization of these ancient systems, as we’ve done here, is paramount to refine our knowledge of our Galaxy’s formation.”

Chris Davis, Program Officer at the National Science Foundation (NSF) for Gemini, commented, “These fabulous results demonstrate why the development of wide-field, high-resolution imaging at Gemini is key to the Observatory’s future. The recent NSF award to support the development of a similar system at Gemini North will make routine super-sharp imaging from both hemispheres a reality. These are certainly exciting times for the Observatory.”

The Gemini observations resolve stars to about 0.1 arcsecond which is one 36 thousandths of a degree and comparable to separating two automobile headlamps from approximately 1,500 miles, or 2,500 kilometers, away (the distance from Manaus to Sao Paulo in Brazil, or from San Francisco to Dallas in the USA). This resolution was obtained using the Gemini South Adaptive Optics Imager (GSAOI) – a near-infrared adaptive optics camera used with the Gemini Multi-conjugate adaptive optics System (GeMS). GeMS is an advanced adaptive optics system utilizing three deformable mirrors to correct for distortions imparted on starlight by turbulence in layers of our atmosphere.

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Media Contact:

Peter Michaud
Public Information and Outreach manager
Gemini Observatory
Email: pmichaud@gemini.edu
Desk: 808-974-2510
Cell: 808-936-6643

Science Contacts:

Leandro Kerber
Universidade Estadual de Santa Cruz, Brazil
Email: lokerber@uesc.br
Cell: +55 11 94724-6073
Desk: +55 73 3680-5167 

Source: Gemini Observatory

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Volunteers wanted to help unlock the secrets of our Universe

An enhanced image of some of the galaxies from AstroQuest” for the ones with multiple galaxies.

An image of AstroQuest galaxy alongside how it looks in the AstroQuest platform once a citizen scientist has ‘helped’ the computer to identify what belongs to the main galaxy and what doesn’t. Credit: ICRAR/AstroQuest

An image of an AstroQuest galaxy alongside how it looks in the AstroQuest platform once a citizen scientist has helped the computer to identify what belongs to the main galaxy and what doesn’t. Credit: ICRAR/AstroQuest

An image of an AstroQuest galaxy alongside how it looks in the AstroQuest platform once a citizen scientist has helped the computer to identify what belongs to the main galaxy and what doesn’t. Credit: ICRAR/AstroQuest

An image of an AstroQuest galaxy alongside how it looks in the AstroQuest platform once a citizen scientist has helped the computer to identify what belongs to the main galaxy and what doesn’t. Credit: ICRAR/AstroQuest

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Scientists are appealing for public help on one of the biggest astronomy projects of the next ten years.

In a new citizen science project launched today (March 22, 2019) — known as AstroQuest— researchers are looking for volunteers to study images of galaxies and figure out which light is coming from which galaxy.

“When you go outside and look up at the night sky, there’s a lot of black with all of the stars dotted around,” said astrophysicist Dr Luke Davies, from the University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR).

“But when you look with a really powerful telescope for a long time, you actually see that there are galaxies and stars everywhere, all over the sky.

“It’s really, really crowded, and all of these galaxies and stars overlap with each other.”

Dr Davies helps lead WAVES—or the Wide Area Vista ExtraGalactic Survey—a million-dollar international project and the biggest spectroscopic galaxy evolution survey ever undertaken.

He said WAVES needs to accurately measure the light coming from millions of galaxies.

“We use sophisticated computer algorithms to make sense of where the light is coming from in these crowded regions,” Dr Davies said.

“But the computer often gets it wrong. It’s simply no match for the human eye and brain.”

Dr Davies said professional astronomers have previously looked through all the galaxies and fixed the computer’s mistakes.

“But as more and more galaxies are surveyed, there simply aren’t enough people on our team to do it,” he said.

ICRAR citizen science project officer Lisa Evans said AstroQuest asks volunteers to take over from professional astronomers and check the computer’s work.

Where the computer has gotten it wrong, volunteers are asked to fix it.

“There’s never been a citizen science project quite like this before,” Ms Evans said.

“This is the first time we’ve got people actually painting over the galaxies and drawing in where they are.”

Ms Evans has also added game features to AstroQuest, including leaderboards, quests and achievements.

Dr Davies said knowing the amount of light that comes from a galaxy can tell us things like how many stars the galaxy currently has, how many stars it’s forming and how much dust is in it.

He said the team is ultimately trying to learn more about how galaxies in the early Universe evolved into the galaxies that we see today.

“If you map out millions of galaxies and measure all of their properties you can actually see how galaxies change as the Universe gets older. You can then explore how things like where a galaxy lives in the Universe and if it’s crashing into other galaxies affect how it evolves with time,” he says.

AstroQuest is a chance for anyone who’s interested in astronomy to be involved in one of the biggest scientific projects of the next ten years, Dr Davies said.

“You can essentially be at the forefront of scientific research and help out a huge million-dollar international project just by being at your computer and drawing over pictures of galaxies,” he said.

Register at astroquest.net.au.

The science behind AstroQuest

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More Information

The International Centre for Radio Astronomy Research (ICRAR) is a joint venture between Curtin University and The University of Western Australia with support and funding from the State Government of Western Australia.

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Multimedia

Full resolution images available for download from here.

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Contacts

Dr Luke Davies (ICRAR-UWA)
Ph: +61 466 277 672
Email: Luke.Davies@icrar.org

Pete Wheeler (Media Contact, ICRAR)
Ph: +61 423 982 018
Email: Pete.Wheeler@icrar.org

Source: International Centre for Radio Astronomy Research (ICRAR)

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NASA’s Webb to Explore Galaxies from Cosmic Dawn to Present Day

Abell 2744, nicknamed Pandora's Cluster, is a giant pile-up of four smaller galaxy clusters. The cluster is so massive that its powerful gravity bends the light from galaxies far behind it, making the background objects appear larger and brighter in a phenomenon called gravitational lensing. Shown in this Hubble image, the mammoth Abell 2744 cluster is located about 3.5 billion light-years away. Credits: NASA, ESA, and J. Lotz, M. Mountain, A. Koekemoer, and the HFF Team (STScI). Hi-res images

How did the first galaxies in the universe form, and did they make the universe transparent to light? How did later galaxies produce and disperse into the universe the heavier elements that are the building blocks of stars, planets, and even humans? These are questions astronomers will address in some of the first observations made by NASA’s James Webb Space Telescope, slated to launch in March 2021. Astronomers hope the answers will lead to a better understanding of the origins and evolution of the universe. 

Through the combined power of NASA’s James Webb Space Telescope and gravity creating “natural telescopes” in space, astronomers hope to answer two science questions that are fundamental to understanding the origins and evolution of the universe:

- How did the first galaxies in the universe form, and did they make the universe transparent to light?

- How did later galaxies produce and disperse into the universe the heavier elements that are the building blocks of stars, planets, and even humans?

These questions will be addressed in some of the first observations made by the Webb telescope, slated to launch in March 2021. These observations will be part of the Director’s Discretionary-Early Release Science program, which provides time to selected projects early in the telescope’s mission. This program allows the astronomical community to quickly learn how best to use Webb’s capabilities, while also yielding robust science.

An international team led by Tommaso Treu of the University of California, Los Angeles, has been investigating how Webb can tackle these two key questions about the universe in the Early Release Science program.

Treu and his team will study the earliest, most distant galaxies to investigate their origins. After the big bang, the universe cooled down. As it cooled, protons and electrons combined to form neutral hydrogen atoms, until the universe became filled with hydrogen and opaque to light. Then at some point, the first galaxies formed, and scientists think these first galaxies emitted enough ultraviolet light to destroy the neutral hydrogen atoms and make the universe transparent to light. This is called the end of the “dark ages.”

“We’re not exactly sure when this happens, and we think it’s galaxies making the universe transparent, but we are not totally sure,” Treu said. “One of the things our proposal will try to do is establish whether indeed galaxies are the ones that are making the universe transparent — ending the cosmic dark ages — and what kind of galaxies they are, what are their properties, and when this happens.”

Using Gravity as a “Natural Telescope”

To see the faintest, farthest galaxies, the team will combine the power of Webb with the magnification of a “natural telescope” in space. The phenomenon, called gravitational lensing, occurs when a huge amount of matter, such as a cluster of galaxies, creates a gravitational field that distorts and magnifies the light from distant galaxies that are behind it, but in the same line of sight. The effect allows researchers to study the details of early galaxies too far away to be seen with current technology and telescopes.

One gravitational lens is Abell 2744, an enormous cluster of four smaller galaxy clusters. Also known as Pandora’s Cluster, this giant collection of galaxies has been well studied, including by NASA’s Hubble Space Telescope. Abell 2744 is one of many clusters that scientists can use in combination with Webb to peer back into the universe’s distant past.

“It’s a cluster that we know very well,” Treu said. “The fact that we know it so well means that we can calculate very precisely the properties of the lens. Using our models, we can compute very accurately how the background images have been distorted. Then we can invert that to figure out the intrinsic properties of the objects as they would look without the lens in front."

Simultaneously, the team will take deep images in the near and medium infrared of two fields offset from the cluster. “We will use those to count galaxies in the very early universe and figure out how many there are,” explained Treu. “Those are the sources that are suspected to eventually produce the ionizing photons that end the dark ages.”

Forming the Universe’s Heavier Elements

The big bang only formed hydrogen, helium, and traces of other light elements. Heavier elements like iron, oxygen, and carbon, which are made in stars, eventually ended up in the universe — but scientists don’t know exactly how this process happened.

“In astronomy, we think of hydrogen and helium as the light elements, and everything else we call a ‘metal,’” explained team member Alaina Henry of the Space Telescope Science Institute in Baltimore, Maryland. “We want to measure the metals that are produced by the first stars in the first supernovae. This tells us how the stars evolve, and how many end their lives as supernovae, where the heaviest elements — such as iron — are made.”

Identifying the “Fingerprints” of Elements in the Light

Answering both questions requires the unique spectroscopic capabilities of the Webb telescope. Spectroscopy separates an object’s light into its component colors, allowing scientists to see the “fingerprints” of different elements. By analyzing these spectral fingerprints, astronomers can determine the physical properties of that object, including its temperature, mass, luminosity, and composition.

Treu and his team will use two different spectrographs on Webb, each with different strengths and functions. Comparing and contrasting these capabilities is an important technical goal of their program.

Webb’s Near Infrared Imager and Slitless Spectrograph (NIRISS) gives observers spatial information, so they can determine how a spectrum changes across the sky. However, it has relatively low spectral resolution, meaning it is harder to differentiate between very similar colors.

The telescope’s Near Infrared Spectrograph (NIRSpec) has a quarter of a million tiny microshutters, each as wide as a human hair. These shutters can be opened or closed individually to isolate the light from a particular object. “In exchange for that, you lose spatial information,” said Treu, “but you get much higher spectral information. You can see the motion of the gas, both within galaxies and flowing in and out of them.”

“Webb will effectively be a much more capable spectrograph than we have ever had in space,” Treu added. “It will have multiple instruments to disperse the light. We need to understand the strengths of each one and how they complement each other.”

Expectations

Looking deep into the cosmos, Treu and his team expect to get a very good idea of the opacity of the universe, and also learn how ionizing photons — particles of light — escaped from the very early galaxies. They will also observe nearer galaxies at later times, when the galaxies are forming stars very vigorously. “We will get the best view ever of this process of gas flowing in, forming stars, and then being blown out by super-winds,” Treu said.

“It would be really fun if we found spectral features that we hadn’t seen very often, or maybe not at all before,” added Henry.

The James Webb Space Telescope will be the world’s premier space science observatory when it launches in 2021. Webb will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

Source: NASA's James Webb Space Telescope/News

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Galactic Center Visualization Delivers Star Power

Galactic Center 360-degree Visualization

 JPEG (287.6 kb) - Large JPEG (3 MB) - Tiff (41.7 MB) - More Images

 A Tour of the Galactic Center - More Animations

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Want to take a trip to the center of the Milky Way? Check out a new immersive, ultra-high-definition visualization. This 360-movie offers an unparalleled opportunity to look around the center of the galaxy, from the vantage point of the central supermassive black hole, in any direction the user chooses.

By combining NASA Ames supercomputer simulations with data from NASA's Chandra X-ray Observatory, this visualization provides a new perspective of what is happening in and around the center of the Milky Way. It shows the effects of dozens of massive stellar giants with fierce winds blowing off their surfaces in the region a few light years away from the supermassive black hole known as Sagittarius A* (Sgr A* for short).

These winds provide a buffet of material for the supermassive black hole to potentially feed upon. As in a previous visualization, the viewer can observe dense clumps of material streaming toward Sgr A*. These clumps formed when winds from the massive stars near Sgr A* collide. Along with watching the motion of these clumps, viewers can watch as relatively low-density gas falls toward Sgr A*. In this new visualization, the blue and cyan colors represent X-ray emission from hot gas, with temperatures of tens of millions of degrees; red shows moderately dense regions of cooler gas, with temperatures of tens of thousands of degrees; and yellow shows of the cooler gas with the highest densities.

A collection of X-ray-emitting gas is seen to move slowly when it is far away from Sgr A*, and then pick up speed and whip around the viewer as it comes inwards. Sometimes clumps of gas will collide with gas ejected by other stars, resulting in a flash of X-rays when the gas is heated up, and then it quickly cools down. Farther away from the viewer, the movie also shows collisions of fast stellar winds producing X-rays. These collisions are thought to provide the dominant source of hot gas that is seen by Chandra.

When an outburst occurs from gas very near the black hole, the ejected gas collides with material flowing away from the massive stars in winds, pushing this material backwards and causing it to glow in X-rays. When the outburst dies down the winds return to normal and the X-rays fade.

The 360-degree video of the Galactic Center is ideally viewed through virtual reality (VR) goggles, such as Samsung Gear VR or Google Cardboard. The video can also be viewed on smartphones using the YouTube app. Moving the phone around reveals a different portion of the movie, mimicking the effect in the VR goggles. Finally, most browsers on a computer also allow 360-degree videos to be shown on YouTube. To look around, either click and drag the video, or click the direction pad in the corner.

Dr. Christopher Russell of the Pontificia Universidad Católica de Chile (Pontifical Catholic University) presented the new visualization at the 17th meeting of the High-Energy Astrophysics (HEAD) of the American Astronomical Society held in Monterey, Calif. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

A Quick Look at the Galactic Center Visualization

Fast Facts for PSS 0133+0400:

Credit: NASA/CXC/Pontifical Catholic Univ. of Chile /C.Russell et al.

Category: Normal Galaxies & Starburst Galaxies, Milky Way Galaxy & Black Holes
Coordinates (J2000): RA 17h 45m 40s | Dec -29° 00´ 28.00"
Constellation: Sagittarius
Instrument: ACIS
References: Russell, C. et al. 2017, MNRAS, 464, 4958, arXiv:1607.01562
Distance Estimate: About 26,000 light years

Source: NASA’s Chandra X-ray Observatory

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Giant chimneys vent X-rays from Milky Way's core

XMM-Newton discovers galactic ‘chimneys’

Copyright: ESA/XMM-Newton/G. Ponti et al. 2019; ESA/Gaia/DPAC (Milky Way map), CC BY-SA 3.0 IGO. Hi-res image

By surveying the centre of our Galaxy, ESA’s XMM-Newton has discovered two colossal ‘chimneys’ funneling material from the vicinity of the Milky Way’s supermassive black hole into two huge cosmic bubbles.

The giant bubbles were discovered in 2010 by NASA’s Fermi Gamma-ray Space Telescope: one stretches above the plane of the Milky Way galaxy and the other below, forming a shape akin to a colossal hourglass that spans about 50 000 light years – around half the diameter of the entire Galaxy. They can be thought of as giant ‘burps’ of material from the central regions of our Milky Way, where its central black hole, known as Sagittarius A*, resides.

Now, XMM-Newton has discovered two channels of hot, X-ray emitting material streaming outwards from Sagittarius A*, finally linking the immediate surroundings of the black hole and the bubbles together.

“We know that outflows and winds of material and energy emanating from a galaxy are crucial in sculpting and altering that galaxy’s shape over time – they are key players in how galaxies and other structures form and evolve throughout the cosmos,” says lead author Gabriele Ponti of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, and the National Institute for Astrophysics in Italy.

“Luckily, our Galaxy gives us a nearby laboratory to explore this in detail, and probe how material flows out into the space around us. We used data gathered by XMM-Newton between 2016 and 2018 to form the most extensive X-ray map ever made of the Milky Way’s core.”

XMM-Newton’s view of the Galactic centre – annotated

Copyright: ESA/XMM-Newton/G. Ponti et al. 2019, Nature. Hi-res image

This map revealed long channels of super-heated gas, each extending for hundreds of light years, streaming above and below the plane of the Milky Way. 

Scientists think that these act as a set of exhaust pipes through which energy and mass are transported from our Galaxy’s heart out to the base of the bubbles, replenishing them with new material. 

This finding clarifies how the activity occurring at the core of our home Galaxy, both present and past, is connected to the existence of larger structures around it. 

The outflow might be a remnant from our Galaxy’s past, from a period when activity was far more prevalent and powerful, or it may prove that even ‘quiescent’ galaxies – those that host a relatively quiet supermassive black hole and moderate levels of star formation like the Milky Way – can boast huge, energetic outflows of material. 

“The Milky Way is seen as a kind of prototype for a standard spiral galaxy,” says co-author Mark Morris of the University of California, Los Angeles, USA. 

“In a sense, this finding sheds light on how all typical spiral galaxies – and their contents – may behave across the cosmos.”

XMM-Newton discovers galactic ‘chimneys’ – annotated
Copyright: ESA/XMM-Newton/G. Ponti et al. 2019; ESA/Gaia/DPAC (Milky Way map), CC BY-SA 3.0 IGO. Hi-res image

Despite its categorisation as quiescent on the cosmic scale of galactic activity, previous data from XMM-Newton have revealed that our Galaxy’s core is still quite tumultuous and chaotic. Dying stars explode violently, throwing their material out into space; binary stars whirl around one another; and Sagittarius A*, a black hole as massive as four million Suns, lies in wait for incoming material to devour, later belching out radiation and energetic particles as it does so.

Cosmic behemoths such as Sagittarius A* – and those even more massive – hosted by galaxies across the cosmos will be explored in depth by upcoming X-ray observatories like ESA’s Athena, the Advanced Telescope for High-Energy Astrophysics, scheduled for launch in 2031. Another future ESA mission, Lisa, the Laser Interferometer Space Antenna, will search for gravitational waves released by the merger of supermassive black holes at the core of distant, merging galaxies.

“There’s still a great deal to be done with XMM-Newton – the telescope could scan a significantly larger region of the Milky Way’s core, which would help us to map the bubbles and hot gas surrounding our Galaxy as well as their connections to the other components of the Milky Way, and hopefully figure out how all of this is linked together,” adds Gabriele.

“Of course, we’re also looking forward to Athena and the breakthrough it will enable.”

Athena will combine extremely high-resolution X-ray spectroscopy with excellent imaging capabilities over wide areas of the sky, allowing scientists to probe the nature and movement of hot cosmic gas like never before.

“This outstanding result from XMM-Newton gives us an unprecedented view of what’s really happening at the core of the Milky Way, and presents the most extensive X-ray map ever created of the entire central region,” says ESA XMM-Newton project scientist Norbert Schartel.

“This is especially exciting in the context of our upcoming missions. XMM-Newton is paving the way for the future generation of X-ray observatories, opening up abundant opportunities for these powerful spacecraft to make substantial new discoveries about our Universe.”

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Notes for editors
 

“An X-ray Chimney extending hundreds of parsecs above and below the Galactic Centre” by G. Ponti et al. is published in the journal Nature.

XMM-Newton data were used in conjunction with archival data from NASA’s Chandra X-Ray Observatory.

The bubbles stretching above and below the Milky Way’s disc are known as Fermi bubbles, and were discovered in gamma-ray data gathered by NASA's Fermi Gamma-ray Space Telescope in 2010.

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For more information, please contact:
 
Gabriele Ponti
Max Planck Institute for Extraterrestrial Physics, Germany
and INAF Brera Astronomical Observatory, Italy
Tel: +39 0272320425
Email: gabriele.ponti@inaf.it

Mark Morris
University of California, Los Angeles, USA
Tel:  +1 310 825 3320
Email: morris@astro.ucla.edu

Norbert Schartel
XMM-Newton project scientist
European Space Agency
Email: norbert.schartel@sciops.esa.int

Markus Bauer
ESA Science Programme Communication Officer
Tel: +31 71 565 6799
Mob: +31 61 594 3 954
Email: markus.bauer@esa.int

Source: ESA/Space Science

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The Rise and Fall of Ziggy Star Formation and the Rich Dust from Ancient Stars

ALMA and Hubble Space Telescope (HST) image of the distant galaxy MACS0416_Y1. Distribution of dust and oxygen gas traced by ALMA are shown in red and green, respectively, while the distribution of stars captured by HST is shown in blue. Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, Tamura, et al.  Hi-res image

Artist’s impression of the distant galaxy MACS0416_Y1. Based on the observations with ALMA and HST, researchers assume that this galaxy contains stellar clusters with a mix of old and young stars. The clouds of gas and dust are illuminated by starlight. Credit: National Astronomical Observatory of Japan. Hi-res image

Researchers have detected a radio signal from abundant interstellar dust in MACS0416_Y1, a galaxy 13.2 billion light-years away in the constellation Eridanus. Standard models can’t explain this much dust in a galaxy this young, forcing us to rethink the history of star formation. Researchers now think MACS0416_Y1 experienced staggered star formation with two intense starburst periods 300 million and 600 million years after the Big Bang with a quiet phase in between. Hi-res image

Stars are the main players in the Universe, but they are supported by the unseen backstage stagehands: stardust and gas. Cosmic clouds of dust and gas are the sites of star formation and masterful storytellers of the cosmic history.

“Dust and relatively heavy elements such as oxygen are disseminated by the deaths of stars,” said Yoichi Tamura, an associate professor at Nagoya University and the lead author of the research paper, “Therefore, a detection of dust at some point in time indicates that a number of stars have already formed and died well before that point.”

Using ALMA (Atacama Large Millimeter/submillimeter Array), Tamura and his team observed the distant galaxy MACS0416_Y1. Because of the finite speed of light, the radio waves we observe from this galaxy today had to travel for 13.2 billion years to reach us. In other words, they provide an image of what the galaxy looked like 13.2 billion years ago, which is only 600 million years after the Big Bang.

The astronomers detected a weak but telltale signal of radio emissions from dust particles in MACS0416_Y1 [1]. The Hubble Space Telescope, the Spitzer Space Telescope, and the European Southern Observatory’s Very Large Telescope have observed the light from stars in the galaxy; and from its color they estimate the stellar age to be 4 million years.

“It ain’t easy,” said Tamura half-lost in a moonage daydream. “The dust is too abundant to have been formed in 4 million years. It is surprising, but we need to hang onto ourselves. Older stars might be hiding in the galaxy, or they may have died out and disappeared already.”

“There have been several ideas proposed to overcome this dust budget crisis,” said Ken Mawatari, a researcher at the University of Tokyo. “However, no one is conclusive. We made a new model which doesn’t need any extreme assumptions diverging far from our knowledge of the life of stars in today’s Universe. The model well explains both the color of the galaxy and the amount of dust.” In this model, the first burst of star formation started at 300 million years and lasted 100 million years. After that, the star formation activity went quiet for a  and then restarted at 600 million years. The researchers think ALMA observed this galaxy at the beginning of its second generation of star formation.

“Dust is a crucial material for planets like Earth,” explains Tamura. “Our result is an important step forward for understanding the early history of the Universe and the origin of dust.”

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Notes

[1] ALMA marginally detected dust emissions in a galaxy A2744_YD1 with a similar age MACS0416_Y1. The detection of dust in the present research has a better signal-to-noise ratio.

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Additional Information

These observation results were published as Tamura et al. “Detection of the Far-infrared [O III] and Dust Emission in a Galaxy at Redshift 8.312: Early Metal Enrichment in the Heart of the Reionization Era” in the Astrophysical Journal in March 2019.

The research team members are:

Yoichi Tamura (Nagoya University), Ken Mawatari (Osaka Sangyo University/The University of Tokyo), Takuya Hashimoto (Osaka Sangyo University/National Astronomical Observatory of Japan), Akio K. Inoue (Osaka Sangyo University), Erik Zackrisson (Uppsala University), Lise Christensen (University of Copenhagen), Christian Binggeli (University of Copenhagen), Yuichi Matsuda (National Astronomical Observatory of Japan/SOKENDAI), Hiroshi Matsuo (National Astronomical Observatory of Japan/SOKENDAI),Tsutomu T. Takeuchi (Nagoya University), Ryosuke S. Asano (Nagoya University), Kaho Sunaga (Nagoya University), Ikkoh Shimizu (Osaka University), Takashi Okamoto (Hokkaido University), Naoki Yoshida (The University of Tokyo), Minju Lee (Nagoya University/National Astronomical Observatory of Japan), Takatoshi Shibuya (Kitami Institute of Technology), Yoshiaki Taniguchi (The Open University of Japan), Hideki Umehata (The Open University of Japan/RIKEN/The University of Tokyo), Bunyo Hatsukade (The University of Tokyo), Kotaro Kohno (The University of Tokyo), and Kazuaki Ota (University of Cambridge/Kyoto University).

This research was supported by JSPS/MEXT KAKENHI (Nos. 17H06130, 17H04831, 17KK0098, 17H01110, 18H04333, and 17K14252) and the Swedish National Space Board.

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 Ministry of Science and Technology (MOST) 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.

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Contacts

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

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

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

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

Source: Atacama Large Millimeter/submillimeter Array (ALMA) /Press Release

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