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  • richardmitnick 4:59 pm on December 21, 2017 Permalink | Reply
    Tags: A century of galaxy discrimination revealed by giant European astronomy survey, , , , , , ESA Herschel   

    From Cardiff: “A century of galaxy discrimination revealed by giant European astronomy survey” Revised for science papers 

    Cardiff University

    Cardiff University

    21 December 2017

    A huge European astronomy survey, whose results are released today (21 December 2017), has revealed that the view of the Universe provided by traditional optical telescopes is seriously biased.

    ESA/Herschel spacecraft

    Why Herschel

    The Herschel ATLAS (H-ATLAS) was a survey carried out by an international team led by researchers at Cardiff University with European Herschel Space Observatory in the far-infrared waveband, which consists of electromagnetic waves with wavelengths 200 times greater than optical light.

    Science papers:

    Valiante et al. 2016 MNRAS
    The Herschel-ATLAS Data Release 1 Paper I: Maps, Catalogues and Number Counts

    Bourne et al. 2016 MNRAS
    The Herschel-ATLAS Data Release 1 Paper II: Multi-wavelength counterparts to submillimetre sources

    MNRAS
    The Herschel-ATLAS: a sample of 500 μm-selected lensed galaxies over 600 deg

    Science
    The Detection of a Population of Submillimeter-Bright, Strongly Lensed Galaxies

    ApJ
    HERSCHEL-ATLAS: A BINARY HyLIRG PINPOINTING A CLUSTER OF STARBURSTING PROTOELLIPTICALS

    MNRAS
    Revealing the complex nature of the strong gravitationally lensed system H-ATLAS J090311.6+003906 using ALMA

    Although Herschel stopped observing in 2013, the Herschel-ATLAS team has spent the last five years analysing their results, and today they released their final images and catalogues, which consist of half-a-million galaxies emitting far-infrared radiation. While the optical light from galaxies is starlight, the far-infrared radiation is from interstellar dust, tiny solid grains of material between the stars.

    Deeply mysterious

    Galaxies, assemblies of stars ranging from 40,000 to thousand billion stars (ours contains about one billion) are the basic building blocks of our Universe. Since they were discovered about a century ago, most of what we know about them has come from optical telescopes. However, when looked at in far-infrared light, the galaxy population looks very different.

    Initially, the team used their results to measure how much dust there is in galaxies today. Cardiff University PhD student Rosie Beeston who led this work said: “Before, astronomers were trying to understand how much dust there is billions of light years away but didn’t really have a handle on how much dust resides in our own astronomical backyard because only a couple of hundred measurements existed. Now we’ve created a census of dust in over 15,000 galaxies.”

    Puzzlingly, the team also found a mysterious class of galaxy with lots of gas and a bigger ratio of dust to star mass than any other type of galaxy. Dubbed BADGERS (Blue and Dusty Gas Rich Galaxies), these galaxies are deeply mysterious, since the huge amounts of dust should hide most of the optical light, and the dust is also very cold.

    Dr Loretta Dunne, a research fellow at the University’s School of Physics and Astronomy, was amazed to discover these odd new galaxies: “I remember checking the optical images of our brightest 300 galaxies and being amazed that they were mostly these really messy looking blue galaxies with no obvious signs of dust. It was totally not at all what I was expecting to see, and the funny thing was I having this eureka moment in Sydney airport on my way to an H-ATLAS meeting in Cardiff.”

    ‘Green valley’ galaxies

    Another discovery made by the team has overturned astronomers’ ideas about how galaxies evolve. All current theories of how galaxies evolve are based on the fundamental assumption that there are two classes of galaxy: galaxies in which stars are actively forming and ‘quiescent galaxies’ in which star formation has essentially stopped. This assumption is based on decades of optical surveys, which have found that most galaxies are either blue (star-forming) or red (quiescent). The existence of these two classes means that all theories need to include a catastrophic process that suddenly (in cosmic terms) converts a star-forming galaxy into a quiescent galaxy.

    Most of the galaxies detected in the Herschel ATLAS, however, fall in the ‘green valley’ between the red and the blue galaxies. According to Professor Steve Eales, of the University’s School of Physics and Astronomy: “This discovery has overturned all the current theories for how galaxies evolve. Our results show that there really is only a single galaxy class…”

    ________________________________________________________

    “There is no longer any need for a violent process that moves a galaxy rapidly from one class to the other.
    Herschel has shown that galaxy evolution is actually quite a gentle process.”

    Professor Stephen Eales,
    ________________________________________________________

    The catalogues and images released by the team today will be a treasure trove for the worldwide community of astronomers. Apart from revolutionising our view of galaxies, the catalogues contain galaxies ranging from ones nearby to ones being seen only a billion years after the big bang, tens of thousands of galaxies magnified by ‘gravitational lensing’, and even tiny clouds of dust in our own galaxy. Since there is no similar mission on the drawing board for either the European Space Agency or NASA, the results from the survey will be a fundamental resource for astronomers for decades to come.

    2
    One of the gravitationally lensed sources found in the survey. The ring is a map made with the Atacama Large Millimetre Array of one of the sources detected in the survey.

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

    The ring is an ‘Einstein ring’ made as the result of the bending of light from the distant Herschel source as the result of the gravitational field from a nearby galaxy (the galaxy in the centre, which was not detected by Herschel).

    Dr Elisabetta Valiante, also of the School, who led the team that produced the galaxy catalogues: “The H-ATLAS survey is a milestone in the history of far-infrared astronomy and I expect it to be a reference for the next generation of researchers studying the formation of stars and galaxies.”

    See the full article here .

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  • richardmitnick 12:22 pm on December 10, 2017 Permalink | Reply
    Tags: , , , , ESA Herschel, , The Chamaeleon I region   

    From ESA via Manu: “Star formation in the Chamaeleon” 


    Manu Garcia, a friend from IAC.

    The universe around us.
    Astronomy, everything you wanted to know about our local universe and never dared to ask.

    ESA Space For Europe Banner

    European Space Agency

    1

    27/11/2017

    ESA/Herschel spacecraft

    A dark cloud when observed with optical telescopes, the Chamaeleon I region reveals itself as an active hub of star formation in this far-infrared image from ESA’s Herschel space observatory. Only around 550 light-years away in the southern constellation of Chamaeleon, it is one of the closest areas where stars are bursting into life.

    Launched in 2009, Herschel observed the sky at far-infrared and submillimetre wavelengths until 2013. Sensitive to the heat from the small fraction of cold dust mixed in with the clouds of gas where stars form, it provided unprecedented views of the interstellar material that pervades our Milky Way galaxy.

    Herschel’s extraordinary scans uncovered a vast and intricate network of filamentary structures everywhere in the Galaxy, confirming that filaments are crucial elements in the process of star formation.

    After a filamentary web arises from turbulent motions of gas in the interstellar material, gravity takes over, but only in the densest filaments, which become unstable and fragment into compact objects – the seeds of future stars.

    Chamaeleon I is no exception, with several elongated structures weaving their way through the cloud. Most of the star-forming activity is taking place at the convergence of filaments – in the bright area towards the top right and in the vaster region just left of the image centre, sprinkled with newborn stars that are heating up the material in their surroundings.

    Analysing images like this, astronomers have identified more than 200 young stars in this two million year-old cloud. Most of these stars are still surrounded by a disc of leftover material from the formation process, which may evolve and later give rise to planets.

    Owing to its relative vicinity, Chamaeleon I is an ideal laboratory to explore protoplanetary discs and their properties using Herschel data.

    This image was first published in a paper by Á. Ribas et al. (2013) [Astronomy & Astrophysics], which presents a study of protoplanetary discs in this region. It was also shared as a #HerschelMoment during a public campaign on Twitter to celebrate the legacy of ESA’s observatory in September 2017.

    This three-colour image combines Herschel observations at 70 microns (blue), 160 microns (green) and 250 microns (red), and spans about 2.5º on the long side; north is to the right and east is up.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 1:35 pm on November 26, 2017 Permalink | Reply
    Tags: , , , , ESA Herschel, Herschel's Chronicles of Galaxy Evolution,   

    From Herschel at ESA via Manu: “Herschel’s Chronicles of Galaxy Evolution” 


    Manu Garcia, a friend from IAC.

    The universe around us.
    Astronomy, everything you wanted to know about our local universe and never dared to ask.

    ESA Space For Europe Banner

    European Space Agency

    September 20, 2017 [Thanks to Manu for digging out this gem of an article.]

    Göran Pilbratt
    Herschel Project Scientist
    Directorate of Science
    European Space Agency
    Email: gpilbratt@cosmos.esa.int
    Phone: +31-71-565-3621

    Philip Appleton
    Herschel Project Scientist and Task Lead at Caltech/IPAC-Herschel
    NASA Herschel Science Center
    Email: apple@ipac.caltech.edu
    Phone: +1-626-395-3119

    1

    Delving deep into the history of our cosmos, the Herschel Space Observatory scrutinised hundreds of thousands of star-forming galaxies, peering back in time to when the Universe was less than one billion years old.

    ESA/Herschel spacecraft

    These observations probed the peak epoch of stellar production, about ten billion years ago, when galaxies were forming stars roughly ten times faster than their present counterparts.

    Looking at the starry spectacle of the night sky, we might be tricked by its seemingly timeless beauty to think that the multitude of distant suns have been there since the beginning of time. But, if our eyes could peer back into cosmic history up to the first few seconds of our Universe, almost 14 billion years ago, they would be treated to a very different view.

    Shortly after the Big Bang – the hot and dense phase that sets our cosmic tale into motion – the Universe was very different from what we can observe nowadays, and it took a few hundred million years for stars and galaxies to start to emerge from the primordial ‘soup’ that filled the early cosmos.

    Piecing together how galaxies formed and evolved, giving birth to stars at different paces throughout the history of the Universe, is one of the most intriguing and challenging topics in present day astrophysics and cosmology research.

    Infrared is the key

    In their quest to investigate how galaxies differ at various cosmic epochs, astronomers have been collecting increasingly larger samples, searching for the light that was emitted by galaxies many billions of years ago and that has been travelling across the Universe ever since. These studies greatly benefit from combining observations at different wavelengths of light, with the infrared band being crucial to pinpoint galaxies that are fiercely forming stars.

    Star formation in galaxies takes place within dense clouds of gas that, for most of cosmic history, also contain small amounts of dust. Newborn stars shine brightly in ultraviolet and visible wavelengths, but only about half of this starlight, on average, leaves a galaxy unhindered; neighbouring dust grains absorb the other half, radiating it again but, this time, at longer wavelengths.

    As a result of the dust interspersed in the interstellar material, galaxies emit roughly 50 per cent of their total light at mid-infrared, far-infrared, and sub-millimetre wavelengths –between 8 micron and 1 mm – with a peak in the far-infrared, around 50-200 microns. For this reason, observations in this spectral range are fundamental for quantifying a galaxy’s star formation activity.

    In addition, the expansion of the Universe stretches the wavelengths of light emitted by distant objects. This effect, known as redshift, becomes increasingly more significant the farther a galaxy is from us.

    This causes the peak of dust emission to move from the far-infrared to sub-millimetre wavelengths. Therefore observations that cover these two portions of the electromagnetic spectrum complement each other, capturing dusty emission from star formation in both nearby and distant galaxies.

    Performing observations at infrared wavelengths with telescopes on the ground, however, is generally difficult – if not impossible – because of the presence of Earth’s atmosphere, so astronomers turned to space.

    In the early 1980s, the US-Dutch-British Infrared Astronomical Satellite (IRAS) was the first space mission to map the sky in the far-infrared, followed by ESA’s Infrared Space Observatory (ISO) in the late 1990s, NASA’s Spitzer Space Telescope, launched in 2003, and JAXA’s Akari, which operated between 2006 and 2011.

    NASA IRAS spacecraft

    2
    ISO spacecraft, ESA

    NASA/Spitzer Infrared Telescope

    JAXA AKARI spacecraft

    With mid-infrared observations from ISO and Spitzer, astronomers started to perceive the glow of warm dust from individual star-forming galaxies sprinkled across the Universe’s history. But it was only with ESA’s Herschel Space Observatory, launched in 2009 and operational until 2013, that these investigations unleashed their full potential.

    The observatory’s broad spectral coverage, including the far-infrared and sub-millimetre range, extended to longer wavelengths than those probed by Spitzer, ISO, and Akari. As a result, astronomers could sense cooler dust than that which had been detected by its predecessors.

    With its unprecedented angular resolution, Herschel could also spot galaxies that had been missed by these earlier observatories at the wavelengths they had in common.

    In addition, and perhaps most importantly, its particular spectral range made it possible to catch galaxies whose light had been redshifted to longer wavelengths than those probed by its predecessors, tracing out star formation to greater distances and thus earlier times in cosmic history.

    With a 3.5-metre primary mirror, Herschel sported the largest infrared telescope flown to date, granting astronomers unprecedented sensitivity that was crucial to observe star-forming galaxies across the Universe.

    Scrutinising the evolution of galaxies was the focus of various Key Programmes that dedicated over 2000 hours to these observations – among them, the Herschel Multi-tiered Extragalactic Survey, the PACS Evolutionary Probe, and the Herschel Thousand Degree Survey.

    Following in the footsteps of previous studies based on Spitzer data, Herschel allowed astronomers to resolve the diffuse ‘fog’ known as the cosmic infrared background radiation into hundreds of thousands of individual, actively star-forming galaxies, seen as they were at a variety of past epochs. Herschel’s contribution was crucial to push the observations up to the time when the Universe was less than one billion years old, probing the full period when star formation peaked and even beyond.

    This result, which has opened new avenues to study the evolution of galaxies, is somewhat suggestive of the revolutionary observations by Galileo who, just over four centuries before, had pointed the newly invented telescope at the diffuse white glow of the Milky Way, breaking it down into a myriad of individual stars.

    The heyday of star formation

    With its deep surveys of several regions of the sky, Herschel revealed a Universe teeming with star-forming galaxies, their presence uncovered by the glow of dust heated by the stars in the making.

    Measuring how bright a galaxy shines in the far-infrared can inform astronomers about how much dust is there and how cool it is, which can be used, in turn, to determine the pace of the galaxy’s star formation activity.

    In the present Universe, galaxies produce stars at a rather leisurely pace, with our Milky Way giving birth to only a few Sun-like stars every year. However, galaxies have been far more prolific in the past, and Herschel has been instrumental in estimating just how much so.

    Stars and galaxies have been bursting into life since the Universe was about half a billion years old, and astronomers now agree that this activity peaked a few billion years later. At that glorious epoch, Herschel confirmed that galaxies were forming stars roughly ten times faster, on average, than they are nowadays.

    Shortly after, the average rate of star formation in galaxies began to decline, and it has been consistently doing so over the past ten billion years of cosmic history.

    With such a marked difference in the star-forming activity of present and past galaxies, it is legitimate to wonder whether the physical processes that regulate the stellar production also underwent any substantial change over the eons.

    Most galaxies in today’s Universe are making stars in a steady, gentle fashion, and only rarely do dynamical interactions of galaxies, or mergers, trigger the occasional, intense burst of stellar birth.

    Astronomers suspected that galactic mergers might have been responsible for the higher pace of star formation at its peak, ten billion years ago, but hints from Spitzer and, later, more robust evidence from Herschel surprisingly revealed that this was not the case.

    In spite of their higher production rates, most galaxies at earlier cosmic epochs seem to be quite ‘ordinary’: their greater productivity is likely an effect of cold gas – the raw material to make stars – being more plentiful at those times.

    Within this scenario, earlier galaxies are not concealing any mysterious mechanism that boosts their star-making efficiency, but are most likely just scaled-up versions of the galaxies we observe at the present time.

    This result relegates merger-triggered starbursts to a minor role in the total history of star formation; the decisive ingredient seems to be a steady supply of cold gas, which could well be provided by intergalactic streams – as suggested by numerical simulation of cosmic structure formation.

    In addition, Herschel demonstrated that, at any given time in the Universe, the vast majority of star-forming galaxies seem to obey a very simple rule: the greater the mass of stars hosted in a galaxy, the faster this galaxy is forming new stars. This relation, called the Galaxy Main Sequence, had already been identified using Spitzer observations of galaxies in more recent epochs, but Herschel confirmed that it applies also to earlier times.

    That such a relation seems to be true across most of cosmic history is remarkable, suggesting that relatively simple mechanisms must be regulating the complex process of a galaxy turning its interstellar material into stars.

    Only a small fraction of extremely prolific starburst galaxies appear to break this rule, in the earlier and later Universe alike. Herschel did find that such behemoths were slightly more abundant at earlier times, but demonstrated that they were never the primary channel of star formation at any epoch. Indeed, the fierce activity of stellar production observed in starburst galaxies seems not to be sustainable over long periods of time, causing them to rapidly quench their star formation.

    More recently, new analyses of Herschel observations have shown that the situation may not be so clear-cut after all. These studies indicate that the Galaxy Main Sequence might break down also in the case of very massive galaxies, suggesting that, as galaxies grow more massive by accreting cold gas, they could reach a point where they stop forming stars very efficiently. The reasons for this change in behaviour are still being investigated.

    The role of feedback

    What caused the drop in star formation rate, ten billion years ago, and its overall declining trend ever since?

    While it is evident that, in the past, galaxies had at their disposal a much larger supply of raw material from which to form stars than they do at present, the physical processes that drained them of their reservoirs of interstellar gas (and dust) are still not fully understood. Similarly, astronomers are still probing the possible mechanisms underlying the Galaxy Main Sequence.

    Another open issue concerns a striking similarity observed between the long-term history of two apparently disparate processes that take place in galaxies: the formation of stars and the accretion of matter onto the supermassive black holes that are lurking at their cores: both processes appear to peak around ten billion years ago. How can the evolution of black holes, which are relatively small-sized and confined at the centre of their host galaxies, be linked to the star-forming activity that takes place on much larger scales?

    The answer to some – or perhaps all – of these questions might lie in the ‘feedback’ effects exerted on the interstellar material that pervades a galaxy by stellar radiation and winds, supernova explosions, and outflows possibly triggered by the activity of its central black hole.

    Astronomers have long been studying the role of feedback on galaxy evolution using a variety of observations across the spectrum. Looking at nearby galaxies that are forming stars more briskly than most of their neighbours, Herschel brought important input to this quest.

    Using Herschel data, astronomers discovered massive outflows of molecular gas streaming away from the cores of several star-forming galaxies in the local Universe. While outflowing gas in neutral and ionised form had been observed in earlier studies, this was the first detection of massive outflows of molecular gas – crucial in the making of stars – being pushed away from a galaxy. The strongest outflows were seen in galaxies that host actively accreting supermassive black holes at their centre, hinting at a role for black-hole feedback in draining a galaxy’s reservoir of star-forming material.

    Further clues were found in nearby radio galaxies, which exhibit symmetric jets of plasma flying out, at the speed of light, from the central black hole. These jets definitely have the power to affect the gas on much larger scales and perhaps even to impede the host galaxy’s star formation.

    Herschel observations were also key to proving a crucial aspect in these feedback matters, uncovering for the first time the causal link between the black hole activity at the centre of a galaxy and the gas outflows seen on much larger scales. This was made possible by comparing a galactic-wide outflow of molecular gas, detected by Herschel, with X-ray data probing a powerful wind of ionised gas driven by the black hole at the core of the galaxy. Observing these two phenomena in the same galaxy for the first time, astronomers further demonstrated the role played by black holes in regulating the formation of stars in their host galaxies.

    Making sense of it all

    To get to the bottom of how differently galaxies evolved across the history of the Universe, observations are compared with the predictions from computer simulations, which attempt to reproduce the build-up of cosmic structures on very large scales. Many new simulations have also embraced the very challenging task of including a number of small-scale processes to account for the feedback effects caused by star formation or the activity of supermassive black holes.

    As for Herschel’s survey of over 12 billion years of star formation, a comparison with the simulated cosmos showed that some processes underlying galaxy evolution seem to be well understood, but many details remain unclear. Simulations are still far from reproducing the complex and diverse properties recorded by surveys of galaxies, especially concerning the link between feedback and star formation, and there is still much work to do before all pieces of this cosmic puzzle fall into place.

    Nevertheless, Herschel’s unprecedented observations are greatly helping astronomers in their ambitious endeavour of assembling the complex history of how stars and galaxies formed and evolved in the cosmos. Pushing the experimental boundaries farther than any of its predecessors, the mission has revealed a number of previously hidden gems, near and far, that have been crucial to piecing together this intriguing tale, while at the same time it also uncovered new mysteries that will keep astronomers busy for the foreseeable future.

    Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA’s Herschel Project Office is based at JPL. JPL contributed mission-enabling technology for two of Herschel’s three science instruments. The NASA Herschel Science Center, part of IPAC at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 11:20 am on November 13, 2017 Permalink | Reply
    Tags: , , , , , Duo of Titanic Galaxies Captured in Extreme Starbursting Merger, ESA Herschel, , ,   

    From ALMA: “Duo of Titanic Galaxies Captured in Extreme Starbursting Merger” 

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

    ALMA

    13 November, 2017

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

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

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

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

    1
    Composite image of ADFS-27 galaxy pair. The background image is from ESA’s Herschel Space Observatory. The object was then detected by ESO’s Atacama Pathfinder Experiment (APEX) telescope (middle image). ALMA (right) was able to identify two galaxies: ADFS-27N (for North) and ADFS-27S (for South). The starbursting galaxies are about 12.8 billion light-years from Earth and destined to merge into a single, massive galaxy. Credit: NRAO/AUI/NSF, B. Saxton; ESA Herschel; ESO APEX; ALMA (ESO/NAOJ/NRAO); D. Riechers

    ESA/Herschel spacecraft

    ESO/APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft)

    New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) have uncovered the never-before-seen close encounter between two astoundingly bright and spectacularly massive galaxies in the early Universe. These so-called hyper-luminous starburst galaxies are exceedingly rare at this epoch of cosmic history — near the time when galaxies first formed — and may represent one of the most-extreme examples of violent star formation ever observed.

    Astronomers captured these two interacting galaxies, collectively known as ADFS-27, as they began the gradual process of merging into a single, massive elliptical galaxy. An earlier sideswiping encounter between the two helped to trigger their astounding bursts of star formation. Astronomers speculate that this merger may eventually form the core of an entire galaxy cluster. Galaxy clusters are among the most massive structures in the Universe.

    “Finding just one hyper-luminous starburst galaxy is remarkable in itself. Finding two of these rare galaxies in such close proximity is truly astounding,” said Dominik Riechers, an astronomer at Cornell University in Ithaca, New York, and lead author on a paper appearing in The Astrophysical Journal. “Considering their extreme distance from Earth and the frenetic star-forming activity inside each, it’s possible we may be witnessing the most intense galaxy merger known to date.”

    The ADFS-27 galaxy pair is located approximately 12.7 billion light-years from Earth in the direction of the Dorado constellation. At this distance, astronomers are viewing this system as it appeared when the Universe was only about one billion years old.

    Astronomers first detected this system with the European Space Agency’s Herschel Space Observatory. It appeared as a single red dot in the telescope’s survey of the southern sky. These initial observations suggested that the apparently faint object was in fact both extremely bright and extremely distant. Follow-up observations with the European Southern Observatory’s Atacama Pathfinder Experiment (APEX) telescope confirmed these initial interpretations and paved the way for the more detailed ALMA observations.

    2
    Artist impression of two starbursting galaxies beginning to merge in the early Universe. Credit: NRAO/AUI/NSF

    With its higher resolution and greater sensitivity, ALMA precisely measured the distance to this object and revealed that it was in fact two distinct galaxies. The pairing of otherwise phenomenally rare galaxies suggests that they reside within a particularly dense region of the Universe at that period in its history, the astronomers said.

    The new ALMA observations also indicate that the ADFS-27 system has approximately 50 times the amount of star-forming gas as the Milky Way. “Much of this gas will be converted into new stars very quickly,” said Riechers. “Our current observations indicate that these two galaxies are indeed producing stars at a breakneck pace, about one thousand times faster than our home galaxy.”

    The galaxies — which would appear as flat, rotating disks — are brimming with extremely bright and massive blue stars. Most of this intense starlight, however, never makes it out of the galaxies themselves; there is simply too much obscuring interstellar dust in each.

    This dust absorbs the brilliant starlight, heating up until it glows brightly in infrared light. As this light travels the vast cosmic distances to Earth, the ongoing expansion of the Universe shifts the once infrared light into longer millimeter and submillimeter wavelengths, all thanks to the Doppler effect.

    ALMA was specially designed to detect and study light of this nature, which enabled the astronomers to resolve the source of the light into two distinct objects. The observations also show the basic structures of the galaxies, revealing tail-like features that were spun-off during their initial encounter.

    The new observations also indicate that the two galaxies are about 30,000 light-years apart, moving at roughly several hundred kilometers per second relative to each other. As they continue to interact gravitationally, each galaxy will eventually slow and fall toward the other, likely leading to several more close encounters before merging into one massive, elliptical galaxy. The astronomers expect this process to take a few hundred million years.

    “Due to their great distance and dustiness, these galaxies remain completely undetected at visible wavelengths,” noted Riechers. “Eventually, we hope to combine the exquisite ALMA data with future infrared observations with NASA’s James Webb Space Telescope.

    NASA/ESA/CSA Webb Telescope annotated

    These two telescopes will form an astronomer’s ‘dream team’ to better understand the nature of this and other such exceptionally rare, extreme systems.”

    The team is composed of Dominik A.Riechers (Cornell University, USA); T.K. Daysy Leung (Cornell University, USA); Rob J.Ivison (European Southern Observatory, Germany, and University of Edinburgh, UK) Ismael Pérez-Fournon (Instituto de Astrofisica de Canarias, y Universidad de La Laguna, Spain); Alexander J.R.Lewis (University of Edinburgh, UK); Rui Marques-Chaves (Instituto de Astrofisica de Canarias, y Universidad de La Laguna, Spain); Ivan Oteo (European Southern Observatory, Germany, and University of Edinburgh, UK); Dave L.Clements (Imperial College London, UK); Asantha Cooray (University of California, Irvine, USA); Josh Greenslade (Imperial College London, UK); Paloma Martínez-Navajas (Instituto de Astrofisica de Canarias, y Universidad de La Laguna, Spain); Seb Oliver (University of Sussex, UK); Dimitra Rigopoulou (University of Oxford, UK, and Rutherford Appleton Laboratory, UK); Douglas Scott (University of British Columbia, Canada), and Axel Weiss (Max-Planck-Institut für Radioastronomie, Germany).

    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.

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  • richardmitnick 8:07 am on February 21, 2017 Permalink | Reply
    Tags: , , , , , ESA Herschel, The thread of star birth   

    From ESA: “The thread of star birth” 

    ESA Space For Europe Banner

    European Space Agency

    1
    Title Star formation on filaments in RCW106
    Released 20/02/2017 9:30 am
    Copyright ESA/Herschel/PACS, SPIRE/Hi-GAL Project. Acknowledgement: UNIMAP / L. Piazzo, La Sapienza – Università di Roma; E. Schisano / G. Li Causi, IAPS/INAF, Italy
    Description

    ESA/Herschel spacecraft
    “ESA/Herschel spacecraft

    Stars are bursting into life all over this image from ESA’s Herschel space observatory. It depicts the giant molecular cloud RCW106, a massive billow of gas and dust almost 12 000 light-years away in the southern constellation of Norma, the Carpenter’s Square.

    Cosmic dust, a minor but crucial ingredient in the interstellar material that pervades our Milky Way galaxy, shines brightly at infrared wavelengths. By tracing the glow of dust with the infrared eye of Herschel, astronomers can explore stellar nurseries in great detail.

    Sprinkled across the image are dense concentrations of the interstellar mixture of gas and dust where stars are being born. The brightest portions, with a blue hue, are being heated by the powerful light from newborn stars within them, while the redder regions are cooler.

    The delicate shapes visible throughout the image are the result of radiation and mighty winds from the young stars carving bubbles and other cavities in the surrounding interstellar material.

    Out of the various bright, blue regions, the one furthest to the left is known as G333.6-0.2 and is one of the most luminous portions of the infrared sky. It owes its brightness to a stellar cluster, home to at least a dozen young and very bright stars that are heating up the gas and dust around them.

    Elongated and thin structures, or filaments, stand out in the tangle of gas and dust, tracing the densest portions of this star-forming cloud. It is largely along these filaments, dotted with many bright, compact cores, that new stars are taking shape.

    Launched in 2009, Herschel observed the sky at far-infrared and submillimetre wavelengths for almost four years. Scanning the Milky Way with its infrared eye, Herschel has revealed an enormous number of filamentary structures, highlighting their universal presence throughout the Galaxy and their role as preferred locations for stellar birth.

    This three-colour image combines Herschel observations at 70 microns (blue), 160 microns (green) and 250 microns (red), and spans over 1º on the long side; north is up and east to the left. The image was obtained as part of Herschel’s Hi-GAL key-project, which imaged the entire plane of the Milky Way in five different infrared bands. A video panorama compiling all Hi-GAL observations was published in April 2016.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 11:03 am on January 29, 2017 Permalink | Reply
    Tags: , , , Dwarf Planet 2007 OR10, ESA Herschel, , ,   

    From JPL-Caltech: “2007 OR10: Largest Unnamed World in the Solar System” 

    NASA JPL Banner

    JPL-Caltech

    May 11, 2016 [Just found this]
    Michele Johnson
    NASA Ames Research Center, Moffett Field, Calif.
    650-604-6982
    michele.johnson@nasa.gov

    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    Elizabeth.landau@jpl.nasa.gov

    Written by Preston Dyches
    Jet Propulsion Laboratory

    1
    New K2 results peg 2007 OR10 as the largest unnamed body in our solar system and the third largest of the current roster of about half a dozen dwarf planets. The dwarf planet Haumea has an oblong shape that is wider on its long axis than 2007 OR10, but its overall volume is smaller. Credits: Konkoly Observatory/András Pál, Hungarian Astronomical Association/Iván Éder, NASA/JHUAPL/SwRI

    Dwarf planets tend to be a mysterious bunch. With the exception of Ceres, which resides in the main asteroid belt between Mars and Jupiter, all members of this class of minor planets in our solar system lurk in the depths beyond Neptune. They are far from Earth – small and cold – which makes them difficult to observe, even with large telescopes. So it’s little wonder astronomers only discovered most of them in the past decade or so.

    Pluto is a prime example of this elusiveness. Before NASA’s New Horizons spacecraft visited it in 2015, the largest of the dwarf planets had appeared as little more than a fuzzy blob, even to the keen-eyed Hubble Space Telescope.

    NASA/New Horizons spacecraft
    NASA/New Horizons spacecraft

    NASA/ESA Hubble Telescope
    NASA/ESA Hubble Telescope

    Given the inherent challenges in trying to observe these far-flung worlds, astronomers often need to combine data from a variety of sources in order to tease out basic details about their properties.

    Recently, a group of astronomers did just that by combining data from two space observatories to reveal something surprising: a dwarf planet named 2007 OR10 is significantly larger than previously thought.


    Access mp4 video here .
    NASA’s Kepler spacecraft observed dwarf planet 2007 OR10 for 19 days in late 2014. The object’s apparent movement (indicated by the arrow) against the stars is caused by Kepler’s changing position as it orbits the sun. The diffuse light at right is from Mars, which was near the field of view. Credits: Konkoly Observatory/László Molnár and András Pál

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    The results peg 2007 OR10 as the largest unnamed world in our solar system and the third largest of the current roster of about half a dozen dwarf planets. The study also found that the object is quite dark and rotating more slowly than almost any other body orbiting our sun, taking close to 45 hours to complete its daily spin.

    For their research, the scientists used NASA’s repurposed planet-hunting Kepler space telescope — its mission now known as K2 — along with the archival data from the infrared Herschel Space Observatory. Herschel was a mission of the European Space Agency with NASA participation. The research paper reporting these results is published in The Astronomical Journal.

    “K2 has made yet another important contribution in revising the size estimate of 2007 OR10. But what’s really powerful is how combining K2 and Herschel data yields such a wealth of information about the object’s physical properties,” said Geert Barentsen, Kepler/K2 research scientist at NASA’s Ames Research Center in Moffett Field, California.

    ESA/Herschel spacecraft
    ESA/Herschel spacecraft

    The revised measurement of the planet’s diameter, 955 miles (1,535 kilometers), is about 60 miles (100 kilometers) greater than the next largest dwarf planet, Makemake, or about one-third smaller than Pluto. Another dwarf planet, named Haumea, has an oblong shape that is wider on its long axis than 2007 OR10, but its overall volume is smaller.

    Like its predecessor mission, K2 searches for the change in brightness of distant objects. The tiny, telltale dip in the brightness of a star can be the signature of a planet passing, or transiting, in front. But, closer to home, K2 also looks out into our solar system to observe small bodies such as comets, asteroids, moons and dwarf planets. Because of its exquisite sensitivity to small changes in brightness, Kepler is an excellent instrument for observing the brightness of distant solar system objects and how that changes as they rotate.

    Figuring out the size of small, faint objects far from Earth is tricky business. Since they appear as mere points of light, it can be a challenge to determine whether the light they emit represents a smaller, brighter object, or a larger, darker one. This is what makes it so difficult to observe 2007 OR10 — although its elliptical orbit brings it nearly as close to the sun as Neptune, it is currently twice as far from the sun as Pluto.

    Enter the dynamic duo of Kepler and Herschel.

    Previous estimates based on Herschel data alone suggested a diameter of roughly 795 miles (1,280 kilometers) for 2007 OR10. However, without a handle on the object’s rotation period, those studies were limited in their ability to estimate its overall brightness, and hence its size. The discovery of the very slow rotation by K2 was essential for the team to construct more detailed models that revealed the peculiarities of this dwarf planet. The rotation measurements even included hints of variations in brightness across its surface.

    Together, the two space telescopes allowed the team to measure the fraction of sunlight reflected by 2007 OR10 (using Kepler) and the fraction absorbed and later radiated back as heat (using Herschel). Putting these two data sets together provided an unambiguous estimation of the dwarf planet’s size and how reflective it is.

    According to the new measurements, the diameter of 2007 OR10 is some 155 miles (250 kilometers) larger than previously thought. The larger size also implies higher gravity and a very dark surface — the latter because the same amount of light is being reflected by a larger body. This dark nature is different from most dwarf planets, which are much brighter. Previous ground-based observations found 2007 OR10 has a characteristic red color, and other researchers have suggested this might be due to methane ices on its surface.

    “Our revised larger size for 2007 OR10 makes it increasingly likely the planet is covered in volatile ices of methane, carbon monoxide and nitrogen, which would be easily lost to space by a smaller object,” said András Pál at Konkoly Observatory in Budapest, Hungary, who led the research. “It’s thrilling to tease out details like this about a distant, new world — especially since it has such an exceptionally dark and reddish surface for its size.”

    As for when 2007 OR10 will finally get a name, that honor belongs to the object’s discoverers. Astronomers Meg Schwamb, Mike Brown and David Rabinowitz spotted it in 2007 as part of a survey to search for distant solar system bodies using the Samuel Oschin Telescope at Palomar Observatory near San Diego.

    Caltech Palomar  Samuel Oschin 48 inch Telescope
    Caltech Palomar  Samuel Oschin 48 inch Telescope Interior with Edwin Hubble
    Caltech Palomar Samuel Oschin 48 inch Telescope

    “The names of Pluto-sized bodies each tell a story about the characteristics of their respective objects. In the past, we haven’t known enough about 2007 OR10 to give it a name that would do it justice,” said Schwamb. “I think we’re coming to a point where we can give 2007 OR10 its rightful name.”

    Ames manages the Kepler and K2 missions for NASA’s Science Mission Directorate. NASA’s Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

    For more information about the Kepler and K2 missions, visit:

    http://www.nasa.gov/kepler

    More information about Herschel is online at:

    http://www.nasa.gov/herschel

    See the full article here .

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    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 1:08 pm on August 29, 2016 Permalink | Reply
    Tags: , ESA Herschel, IRAS 19312+1950, ,   

    From JPL: “NASA Team Probes Peculiar Age-Defying Star” 

    NASA JPL Banner

    JPL-Caltech

    August 29, 2016
    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    elizabeth.landau@jpl.nasa.gov

    Written by Elizabeth Zubritsky
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    1
    An age-defying star called IRAS 19312+1950 exhibits features characteristic of a very young star and a very old star. The object stands out as extremely bright inside a large, chemically rich cloud of material, as shown in this image from NASA’s Spitzer Space Telescope. IRAS 19312+1950 is the bright red star in the center of this image. Image credit: NASA/JPL-Caltech

    A NASA-led team of scientists thinks the star — which is about 10 times as massive as our sun and emits about 20,000 times as much energy — is a newly forming protostar. That was a big surprise, because the region had not been known as a stellar nursery before. But the presence of a nearby interstellar bubble, which indicates the presence of a recently formed massive star, also supports this idea.

    For years, astronomers have puzzled over a massive star lodged deep in the Milky Way that shows conflicting signs of being extremely old and extremely young.

    Researchers initially classified the star as elderly, perhaps a red supergiant. But a new study by a NASA-led team of researchers suggests that the object, labeled IRAS 19312+1950, might be something quite different — a protostar, a star still in the making.

    “Astronomers recognized this object as noteworthy around the year 2000 and have been trying ever since to decide how far along its development is,” said Martin Cordiner, an astrochemist working at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. He is the lead author of a paper in the Astrophysical Journal describing the team’s findings, from observations made using NASA’s Spitzer Space Telescope and ESA’s Herschel Space Observatory.

    NASA/Spitzer Telescope
    NASA/Spitzer Telescope

    ESA/Herschel
    ESA/Herschel

    Located more than 12,000 light-years from Earth, the object first stood out as peculiar when it was observed at particular radio frequencies. Several teams of astronomers studied it using ground-based telescopes and concluded that it is an oxygen-rich star about 10 times as massive as the sun. The question was: What kind of star?

    Some researchers favor the idea that the star is evolved — past the peak of its life cycle and on the decline. For most of their lives, stars obtain their energy by fusing hydrogen in their cores, as the sun does now. But older stars have used up most of their hydrogen and must rely on heavier fuels that don’t last as long, leading to rapid deterioration.

    Two early clues — intense radio sources called masers — suggested the star was old. In astronomy, masers occur when the molecules in certain kinds of gases get revved up and emit a lot of radiation over a very limited range of frequencies. The result is a powerful radio beacon — the microwave equivalent of a laser.

    One maser observed with IRAS 19312+1950 is almost exclusively associated with late-stage stars. This is the silicon oxide maser, produced by molecules made of one silicon atom and one oxygen atom. Researchers don’t know why this maser is nearly always restricted to elderly stars, but of thousands of known silicon oxide masers, only a few exceptions to this rule have been noted.

    Also spotted with the star was a hydroxyl maser, produced by molecules comprised of one oxygen atom and one hydrogen atom. Hydroxyl masers can occur in various kinds of astronomical objects, but when one occurs with an elderly star, the radio signal has a distinctive pattern — it’s especially strong at a frequency of 1612 megahertz. That’s the pattern researchers found in this case.

    Even so, the object didn’t entirely fit with evolved stars. Especially puzzling was the smorgasbord of chemicals found in the large cloud of material surrounding the star. A chemical-rich cloud like this is typical of the regions where new stars are born, but no such stellar nursery had been identified near this star.

    Scientists initially proposed that the object was an old star surrounded by a surprising cloud typical of the kind that usually accompanies young stars. Another idea was that the observations might somehow be capturing two objects: a very old star and an embryonic cloud of star-making material in the same field.

    Cordiner and his colleagues began to reconsider the object, conducting observations using ESA’s Herschel Space Observatory and analyzing data gathered earlier with NASA’s Spitzer Space Telescope. Both telescopes operate at infrared wavelengths, which gave the team new insight into the gases, dust and ices in the cloud surrounding the star.

    The additional information leads Cordiner and colleagues to think the star is in a very early stage of formation. The object is much brighter than it first appeared, they say, emitting about 20,000 times the energy of our sun. The team found large quantities of ices made from water and carbon dioxide in the cloud around the object. These ices are located on dust grains relatively close to the star, and all this dust and ice blocks out starlight making the star seem dimmer than it really is.

    In addition, the dense cloud around the object appears to be collapsing, which happens when a growing star pulls in material. In contrast, the material around an evolved star is expanding and is in the process of escaping to the interstellar medium. The entire envelope of material has an estimated mass of 500 to 700 suns, which is much more than could have been produced by an elderly or dying star.

    “We think the star is probably in an embryonic stage, getting near the end of its accretion stage — the period when it pulls in new material to fuel its growth,” said Cordiner.

    Also supporting the idea of a young star are the very fast wind speeds measured in two jets of gas streaming away from opposite poles of the star. Such jets of material, known as a bipolar outflow, can be seen emanating from young or old stars. However, fast, narrowly focused jets are rarely observed in evolved stars. In this case, the team measured winds at the breakneck speed of at least 200,000 miles per hour (90 kilometers per second) — a common characteristic of a protostar.

    Still, the researchers acknowledge that the object is not a typical protostar. For reasons they can’t explain yet, the star has spectacular features of both a very young and a very old star.

    “No matter how one looks at this object, it’s fascinating, and it has something new to tell us about the life cycles of stars,” said Steven Charnley, a Goddard astrochemist and co-author of the paper.

    NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission, whose science operations are conducted at the Spitzer Science Center. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado.

    Herschel is an ESA space observatory with science instruments provided by European-led principal investigator consortia and with important participation from NASA.

    For more information, visit:

    http://www.nasa.gov/spitzer

    See the full article here .

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    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 12:06 pm on May 23, 2016 Permalink | Reply
    Tags: , , ESA Herschel, ESA Hi-Gal   

    From ESA: “The Little Fox and the Giant Stars” 

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    European Space Agency

    23/05/2016
    No writer credit found

    1

    New stars are the lifeblood of our Galaxy, and there is enough material revealed by this Herschel infrared image to build stars for millions of years to come.

    ESA/Herschel
    ESA/Herschel

    Situated 8000 light-years away in the constellation Vulpecula – latin for little fox – the region in the image is known as Vulpecula OB1. It is a ‘stellar association’ in which a batch of truly giant ‘OB’ stars is being born.

    The vast quantities of ultraviolet and other radiation emitted by these stars is compressing the surrounding cloud, causing nearby regions of dust and gas to begin the collapse into more new stars. In time, this process will ‘eat’ its way through the cloud, transforming some of the raw material into shining new stars.

    The image was obtained as part of Herschel’s Hi-GAL key-project. This used the infrared space observatory’s instruments to image the entire galactic plane in five different infrared wavelengths.

    3
    This fantastic picture is a 70-170-350um composite image of the Galactic Plane at the longitude of 59° in the Vulpecula region. Most remarkable features that can be seen are shock fronts from HII regions, bubbles, Interstellar medium structured at all scales, and remarkable filamentary structures with on-going star formation.

    These wavelengths reveal cold material, most of it between -220ºC and -260ºC. None of it can be seen at ordinary optical wavelengths, but this infrared view shows astronomers a surprising amount of structure in the cloud’s interior.

    The surprise is that the Hi-GAL survey has revealed a spider’s web of filaments that stretches across the star-forming regions of our Galaxy. Part of this vast network can be seen in this image as a filigree of red and orange threads.

    At visual wavelengths, the OB association is linked to a star cluster catalogued as NGC 6823. It was discovered by William Herschel in 1785 and contains 50–100 stars. A nebula emitting visible light, catalogued as NGC 6820, is also part of this multi-faceted star-forming region.

    The giant stars at the heart of Vulpecula OB1 are some of the biggest in the Galaxy. Containing dozens of times the mass of the Sun, they have short lives, astronomically speaking, because they burn their fuel so quickly.

    At an estimated age of two million years, they are already well through their lifespans. When their fuel runs out, they will collapse and explode as supernovas. The shock this will send through the surrounding cloud will trigger the birth of even more stars, and the cycle will begin again.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 2:27 pm on May 11, 2016 Permalink | Reply
    Tags: 2007 OR10 largest unnamed body in our solar system, , , ESA Herschel,   

    From JPL-Caltech: “2007 OR10: Largest Unnamed World in the Solar System” 

    NASA JPL Banner

    JPL-Caltech

    May 11, 2016
    Michele Johnson
    NASA Ames Research Center, Moffett Field, Calif.
    650-604-6982
    michele.johnson@nasa.gov

    Elizabeth Landau
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-6425
    Elizabeth.landau@jpl.nasa.gov

    Written by Preston Dyches
    Jet Propulsion Laboratory

    1
    New K2 results peg 2007 OR10 as the largest unnamed body in our solar system and the third largest of the current roster of about half a dozen dwarf planets. The dwarf planet Haumea has an oblong shape that is wider on its long axis than 2007 OR10, but its overall volume is smaller. Credits: Konkoly Observatory/András Pál, Hungarian Astronomical Association/Iván Éder, NASA/JHUAPL/SwRI

    Konkoly Observatory at Piszkesteto Mountain Station, Hungary
    Konkoly Observatory Budapest Hungary
    Konkoly Observatory at Piszkesteto Mountain Station, Hungary

    Dwarf planets tend to be a mysterious bunch. With the exception of Ceres, which resides in the main asteroid belt between Mars and Jupiter, all members of this class of minor planets in our solar system lurk in the depths beyond Neptune. They are far from Earth – small and cold – which makes them difficult to observe, even with large telescopes. So it’s little wonder astronomers only discovered most of them in the past decade or so.

    Pluto is a prime example of this elusiveness. Before NASA’s New Horizons spacecraft visited it in 2015, the largest of the dwarf planets had appeared as little more than a fuzzy blob, even to the keen-eyed Hubble Space Telescope. Given the inherent challenges in trying to observe these far-flung worlds, astronomers often need to combine data from a variety of sources in order to tease out basic details about their properties.

    Recently, a group of astronomers did just that by combining data from two space observatories to reveal something surprising: a dwarf planet named 2007 OR10 is significantly larger than previously thought.

    The results peg 2007 OR10 as the largest unnamed world in our solar system and the third largest of the current roster of about half a dozen dwarf planets. The study also found that the object is quite dark and rotating more slowly than almost any other body orbiting our sun, taking close to 45 hours to complete its daily spin.

    For their research, the scientists used NASA’s repurposed planet-hunting Kepler space telescope — its mission now known as K2 — along with the archival data from the infrared Herschel Space Observatory. Herschel was a mission of the European Space Agency with NASA participation. The research paper* reporting these results is published in The Astronomical Journal.

    ESA Herschel
    ESA Herschel

    “K2 has made yet another important contribution in revising the size estimate of 2007 OR10. But what’s really powerful is how combining K2 and Herschel data yields such a wealth of information about the object’s physical properties,” said Geert Barentsen, Kepler/K2 research scientist at NASA’s Ames Research Center in Moffett Field, California.

    The revised measurement of the planet’s diameter, 955 miles (1,535 kilometers), is about 60 miles (100 kilometers) greater than the next largest dwarf planet, Makemake, or about one-third smaller than Pluto. Another dwarf planet, named Haumea, has an oblong shape that is wider on its long axis than 2007 OR10, but its overall volume is smaller.

    Like its predecessor mission, K2 searches for the change in brightness of distant objects. The tiny, telltale dip in the brightness of a star can be the signature of a planet passing, or transiting, in front.

    Planet transit. NASA
    Planet transit. NASA

    But, closer to home, K2 also looks out into our solar system to observe small bodies such as comets, asteroids, moons and dwarf planets. Because of its exquisite sensitivity to small changes in brightness, Kepler is an excellent instrument for observing the brightness of distant solar system objects and how that changes as they rotate.

    Figuring out the size of small, faint objects far from Earth is tricky business. Since they appear as mere points of light, it can be a challenge to determine whether the light they emit represents a smaller, brighter object, or a larger, darker one. This is what makes it so difficult to observe 2007 OR10 — although its elliptical orbit brings it nearly as close to the sun as Neptune, it is currently twice as far from the sun as Pluto.

    Enter the dynamic duo of Kepler and Herschel.

    Previous estimates based on Herschel data alone suggested a diameter of roughly 795 miles (1,280 kilometers) for 2007 OR10. However, without a handle on the object’s rotation period, those studies were limited in their ability to estimate its overall brightness, and hence its size. The discovery of the very slow rotation by K2 was essential for the team to construct more detailed models that revealed the peculiarities of this dwarf planet. The rotation measurements even included hints of variations in brightness across its surface.

    Together, the two space telescopes allowed the team to measure the fraction of sunlight reflected by 2007 OR10 (using Kepler) and the fraction absorbed and later radiated back as heat (using Herschel). Putting these two data sets together provided an unambiguous estimation of the dwarf planet’s size and how reflective it is.

    According to the new measurements, the diameter of 2007 OR10 is some 155 miles (250 kilometers) larger than previously thought. The larger size also implies higher gravity and a very dark surface — the latter because the same amount of light is being reflected by a larger body. This dark nature is different from most dwarf planets, which are much brighter. Previous ground-based observations found 2007 OR10 has a characteristic red color, and other researchers have suggested this might be due to methane ices on its surface.

    “Our revised larger size for 2007 OR10 makes it increasingly likely the planet is covered in volatile ices of methane, carbon monoxide and nitrogen, which would be easily lost to space by a smaller object,” said András Pál at Konkoly Observatory in Budapest, Hungary, who led the research. “It’s thrilling to tease out details like this about a distant, new world — especially since it has such an exceptionally dark and reddish surface for its size.”

    As for when 2007 OR10 will finally get a name, that honor belongs to the object’s discoverers. Astronomers Meg Schwamb, Mike Brown and David Rabinowitz spotted it in 2007 as part of a survey to search for distant solar system bodies using the Samuel Oschin Telescope at Palomar Observatory near San Diego.

    “The names of Pluto-sized bodies each tell a story about the characteristics of their respective objects. In the past, we haven’t known enough about 2007 OR10 to give it a name that would do it justice,” said Schwamb. “I think we’re coming to a point where we can give 2007 OR10 its rightful name.”

    Ames manages the Kepler and K2 missions for NASA’s Science Mission Directorate. NASA’s Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

    For more information about the Kepler and K2 missions, visit:

    http://www.nasa.gov/kepler

    More information about Herschel is online at:

    http://www.nasa.gov/herschel

    *Science paper:
    LARGE SIZE AND SLOW ROTATION OF THE TRANS-NEPTUNIAN OBJECT (225088) 2007 OR10 DISCOVERED FROM HERSCHEL AND K2 OBSERVATIONS

    See the full article here .

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    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 4:24 pm on April 22, 2016 Permalink | Reply
    Tags: , , ESA Herschel, Herschel’s view of the Eagle Nebula   

    From ESA: “Herschel’s view of the Eagle Nebula” 

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    European Space Agency

    4.22.16

    Temp 1

    The Eagle Nebula, also known as M 16, seen by ESA’s Herschel space observatory. The nebula lies about 6500 light-years away.

    ESA/Herschel
    ESA/Herschel

    A group of young, bright stars, not visible at these infrared wavelengths, are located near the centre of the image. The powerful light emitted by these stars is setting the surrounding gas ablaze, causing it to shine; the stars also drive mighty winds that are carving the giant cavities in the cloud.

    At the borders of these cavities, the interstellar mixture of gas and dust becomes denser, eventually collapsing and giving rise to a new generation of stars.

    The image is a composite of the wavelengths of 70 microns (blue), 160 microns (green) and 350 microns (red).

    Acknowledgement: G. Li Causi, IAPS/INAF, Italy
    Credits: ESA/Herschel/PACS, SPIRE/Hi-GAL Project

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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