Saturday, July 23, 2016

X Marks the Spot for Milky Way Formation

Researchers used data from NASA's Wide-field Infrared Survey Explorer (WISE) mission to highlight the X-shaped structure in the bulge of the Milky Way. Credit: NASA/JPL-Caltech/D.Lang.   › Full image and caption


To reveal the X shape in the Milky Way's central bulge, researchers took WISE observations and subtracted a model of how stars would be distributed in a symmetrical bulge. Credit: NASA/JPL-Caltech/D.Lang.  › Larger image


A new understanding of our galaxy's structure began in an unlikely way: on Twitter. A research effort sparked by tweets led scientists to confirm that the Milky Way's central bulge of stars forms an "X" shape. The newly published study uses data from NASA's Wide-field Infrared Survey Explorer (WISE) mission.

The unconventional collaboration started in May 2015 when Dustin Lang, an astronomer at the Dunlap Institute of the University of Toronto, posted galaxy maps to Twitter, using data from WISE's two infrared surveys of the entire sky in 2010. Infrared light allows astronomers to see the structures of galaxies in spite of dust, which blocks crucial details in visible light. Lang was using the WISE data in a project to map the web of galaxies far outside our Milky Way, which he made available through an interactive website.

But it was the Milky Way's appearance in the tweets that got the attention of other astronomers. Some chimed in about the appearance of the bulge, a football-shaped central structure that is three-dimensional compared to the galaxy's flat disk. Within the bulge, the WISE data seemed to show a surprising X structure, which had never been as clearly demonstrated before in the Milky Way. Melissa Ness, a postdoctoral researcher at the Max Planck Institute for Astronomy in Heidelberg, Germany, recognized the significance of the X shape, and contacted Lang.

The two met a few weeks later at a conference in Michigan, and decided to collaborate on analyzing the bulge using Lang's WISE maps. Their work resulted in a new study published in the Astronomical Journal confirming an X-shaped distribution of stars in the bulge.

"The bulge is a key signature of formation of the Milky Way," said Ness, the study's lead author. "If we understand the bulge we will understand the key processes that have formed and shaped our galaxy."

The Milky Way is an example of a disk galaxy -- a collection of stars and gas in a rotating disk. In these kinds of galaxies, when the thin disk of gas and stars is sufficiently massive, a "stellar bar" may form, consisting of stars moving in a box-shaped orbit around the center. Our own Milky Way has a bar, as do nearly two-thirds of all nearby disk galaxies.

Over time, the bar may become unstable and buckle in the center. The resulting "bulge" would contain stars that move around the galactic center, perpendicular to the plane of the galaxy, and in and out radially. When viewed from the side, the stars would appear distributed in a box-like or peanut-like shape as they orbit. Within that structure, according to the new study, there is a giant X-shaped structure of stars crossing at the center of the galaxy.

A bulge can also form when galaxies merge, but the Milky Way has not merged with any large galaxy in at least 9 billion years.

"We see the boxy shape, and the X within it, clearly in the WISE image, which demonstrates that internal formation processes have driven the bulge formation," Ness said. "This also reinforces the idea that our galaxy has led a fairly quiet life, without major merging events since the bulge was formed, as this shape would have been disrupted if we had any major interactions with other galaxies."

The Milky Way's X-shaped bulge had been reported in previous studies. Images from the NASA Cosmic Background Explorer (COBE) satellite's Diffuse Infrared Background Experiment suggested a boxy structure for the bulge. In 2013, scientists at the Max Planck Institute for Extraterrestrial Physics published 3-D maps of the Milky Way that also included an X-shaped bulge, but these studies did not show an actual image of the X shape. Ness and Lang's study uses infrared data to show the clearest indication yet of the X shape.

Additional research is ongoing to analyze the dynamics and properties of the stars in the Milky Way's bulge.
Collaborating on this study was unusual for Lang -- his expertise is in using computer science to understand large-scale astronomical phenomena, not the dynamics and structure of the Milky Way. But he was able to enter a new field of research because he posted maps to social media and used openly accessible WISE data.

"To me, this study is an example of the interesting, serendipitous science that can come from large data sets that are publicly available," he said. "I'm very pleased to see my WISE sky maps being used to answer questions that I didn't even know existed."

NASA's Jet Propulsion Laboratory, Pasadena, California, manages and operates WISE for NASA's Science Mission Directorate in Washington. The spacecraft was put into hibernation mode in 2011, after it scanned the entire sky twice, thereby completing its main objectives. In September 2013, WISE was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify potentially hazardous near-Earth objects.


For more information on WISE, visit:  http://www.nasa.gov/wise


News Media Contact

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


Friday, July 22, 2016

Space... the final frontier

Abell S1063, the final frontier

PR Image heic1615b
Parallel field of Abell S1063 

PR Image heic1615c
Wide-field image of Abell S1063 (ground-based image)



Videos

Zoom into Abell S1063
Zoom into Abell S1063

Pan across the galaxy cluster Abell S1063

Pan across the galaxy cluster Abell S1063

Abell S1063 in fulldome
Abell S1063 in fulldome



Fifty years ago Captain Kirk and the crew of the starship Enterprise began their journey into space — the final frontier. Now, as the newest Star Trek film hits cinemas, the NASA/ESA Hubble space telescope is also exploring new frontiers, observing distant galaxies in the galaxy cluster Abell S1063 as part of the Frontier Fields programme.

Space... the final frontier. These are the stories of the Hubble Space Telescope. Its continuing mission, to explore strange new worlds and to boldly look where no telescope has looked before.

The newest target of Hubble’s mission is the distant galaxy cluster Abell S1063, potentially home to billions of strange new worlds.

This view of the cluster, which can be seen in the centre of the image, shows it as it was four billion years ago. But Abell S1063 allows us to explore a time even earlier than this, where no telescope has really looked before. The huge mass of the cluster distorts and magnifies the light from galaxies that lie behind it due to an effect called gravitational lensing. This allows Hubble to see galaxies that would otherwise be too faint to observe and makes it possible to search for, and study, the very first generation of galaxies in the Universe. “Fascinating”, as a famous Vulcan might say.

The first results from the data on Abell S1063 promise some remarkable new discoveries. Already, a galaxy has been found that is observed as it was just a billion years after the Big Bang.

Astronomers have also identified sixteen background galaxies whose light has been distorted by the cluster, causing multiple images of them to appear on the sky. This will help astronomers to improve their models of the distribution of both ordinary and dark matter in the galaxy cluster, as it is the gravity from these that causes the distorting effects. These models are key to understanding the mysterious nature of dark matter.

Abell S1063 is not alone in its ability to bend light from background galaxies, nor is it the only one of these huge cosmic lenses to be studied using Hubble. Three other clusters have already been observed as part of the Frontier Fields programme, and two more will be observed over the next few years, giving astronomers a remarkable picture of how they work and what lies both within and beyond them [1].

Data gathered from the previous galaxy clusters were studied by teams all over the world, enabling them to make important discoveries, among them galaxies that existed only hundreds of million years after the Big Bang (heic1523) and the first predicted appearance of a gravitationally lensed supernova (heic1525).

Such an extensive international collaboration would have made Gene Roddenberry, the father of Star Trek, proud. In the fictional world Roddenberry created, a diverse crew work together to peacefully explore the Universe. This dream is partially achieved by the Hubble programme in which the European Space Agency (ESA), supported by 22 member states, and NASA collaborate to operate one of the most sophisticated scientific instruments in the world. Not to mention the scores of other international science teams that cross state, country and continental borders to achieve their scientific aims.



Notes

[1] The Hubble Frontier Fields is a three-year, 840-orbit programme which will yield the deepest views of the Universe to date, combining the power of Hubble with the gravitational amplification of light around six different galaxy clusters to explore more distant regions of space than could otherwise be seen.



More Information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.
Image credit: NASA, ESA, and J. Lotz (STScI)


 
Links



Contacts

Mathias Jäger
ESA/Hubble Public Information Officer
Garching bei München, Germany
Tel: +49 176 62397500
Email: mjaeger@partner.eso.org


A galaxy fit to burst

Credit: ESA/Hubble & NASA
Acknowledgement: Judy Schmidt (Geckzilla)


This NASA/ESA Hubble Space Telescope image reveals the vibrant core of the galaxy NGC 3125. Discovered by John Herschel in 1835, NGC 3125 is a great example of a starburst galaxy — a galaxy in which unusually high numbers of new stars are forming, springing to life within intensely hot clouds of gas.
Located approximately 50 million light-years away in the constellation of Antlia (The Air Pump), NGC 3125 is similar to, but unfathomably brighter and more energetic than, one of the Magellanic Clouds.    Spanning 15 000 light-years, the galaxy displays massive and violent bursts of star formation, as shown by the hot, young, and blue stars scattered throughout the galaxy’s rose-tinted core. Some of these clumps of stars are notable — one of the most extreme Wolf–Rayet star clusters in the local Universe, NGC 3125-A1, resides within NGC 3125.

Despite their appearance, the fuzzy white blobs dotted around the edge of this galaxy are not stars, but globular clusters. Found within a galaxy’s halo, globular clusters are ancient collections of hundreds of thousands of stars. They orbit around galactic centres like satellites — the Milky Way, for example, hosts over 150 of them.



Thursday, July 21, 2016

1.2 Million Galaxies in 3D

This is one slice through the map of the large-scale structure of the Universe from the Sloan Digital Sky Survey and its Baryon Oscillation Spectroscopic Survey. Each dot in this picture indicates the position of a galaxy 6 billion years into the past. The image covers about 1/20th of the sky, a slice of the Universe 6 billion light-years wide, 4.5 billion light-years high, and 500 million light-years thick. Colour indicates distance from Earth, ranging from yellow on the near side of the slice to purple on the far side. Galaxies are highly clustered, revealing superclusters and voids whose presence is seeded in the first fraction of a second after the Big Bang. This image contains 48,741 galaxies, about 3% of the full survey dataset. Grey patches are small regions without survey data. Image credit: Daniel Eisenstein and SDSS-III. Hi-res image

This is a section of the three-dimensional map constructed by BOSS. The rectangle on the left shows a cut-out of 1000 sq. degrees in the sky containing nearly 120,000 galaxies, or roughly 10% of the total survey. The spectroscopic measurements of each galaxy - every dot in that cut-out - transform the two-dimensional picture into a three-dimensional map, extending our view out to 7 billion years in the past. The brighter regions in this map correspond to the regions of the Universe with more galaxies and therefore more dark matter. The extra matter in those regions creates an excess gravitational pull, which makes the map a test of Einstein’s theory of gravity. © Jeremy Tinker und SDSS-III. Hi-res image


What are the properties of Dark Energy? This question is one of the most intriguing ones in astronomy and scientists are one step closer in answering this question with the largest three-dimensional map of the universe so far: This map contains 1.2 million galaxies in a volume spanning 650 cubic billion light years. Hundreds of scientists from the Sloan Digital Sky Survey III (SDSS-III) – including researchers at the Max Planck Institutes for Extraterrestrial Physics and for Astrophyics - used this map to make one of the most precise measurements yet of dark energy. They found excellent agreement with the standard cosmological model and confirmed that dark energy is highly consistent with a cosmological constant.

"We have spent a decade collecting measurements of 1.2 million galaxies over one quarter of the sky to map out the structure of the Universe over a volume of 650 cubic billion light years,” says Jeremy Tinker of New York University, a co-leader of the scientific team that led this effort. Hundreds of scientists are part of the Sloan Digital Sky Survey III (SDSS-III) team.

These new measurements were carried out by the Baryon Oscillation Spectroscopic Survey (BOSS) programme of SDSS-III. Shaped by a continuous tug-of-war between dark matter and dark energy, the map revealed by BOSS allows astronomers to measure the expansion rate of the Universe by determining the size of the so-called baryonic acoustic oscillations (BAO) in the three-dimensional distribution of galaxies.

Pressure waves travelled through the young Universe up to when it was only 400,000 years old at which point they became frozen in the matter distribution of the Universe. The end result is that galaxies are preferentially separated by a characteristic distance, which astronomers call the BAO scale. The primordial size of the BAO scale is exquisitely determined from observations of the cosmic microwave background.

Ariel Sanchez of the Max-Planck Institute of Extraterrestrial Physics (MPE) led the effort to estimate the exact amount of dark matter and dark energy based on the BOSS data and explains: "Measuring the acoustic scale across cosmic history gives a direct ruler with which to measure the Universe’s expansion rate.  With BOSS, we have traced the BAO’s subtle imprint on the distribution of galaxies spanning a range of time from 2 to 7 billion years ago."

For the very precise measurements, however, the data had to be painstakingly analysed. Especially the determination of distances to the galaxies posed a big challenge. This is inferred from the galaxy spectra, which show that a galaxy’s light is shifted to the red part of the spectrum because it moves away from us. This so-called redshift is correlated with a galaxy’s distance: The farther a galaxy is away from us, the faster it moves.

“However, galaxies also have peculiar motions and the peculiar velocity component along the line-of-sight leads to the so-called redshift space distortion,” explains Shun Saito from the Max Planck Institute for Astrophysics (MPA), who contributed sophisticated models to the BOSS data analysis. “This makes the galaxy distribution anisotropic because the line-of-sight direction is now special – only along this direction the distance is measured through a redshift, which is contaminated by peculiar velocity. In other words, the characteristic anisotropic pattern allows us to measure the peculiar velocity of galaxies – and because the motion of galaxies is governed by gravity, we can use this measurement to constrain to what level Einstein’s general relativity is correct at cosmological scales. In order to properly interpret the data, we have developed a refined model to describe the galaxy distribution.”

Another approach, used by a junior MPE researcher for his PhD thesis, is to use the angular positions of galaxies on the sky instead of physical 3D positions. “This method uses only observables,” explains Salvador Salazar. “We make no prior assumptions about the cosmological model.”

Around the world, other groups all used slightly different models and methodologies to analyse the huge BOSS data set. “We now have seven measurements, which are slightly different, but highly correlated,” Ariel Sanchez points out. “To extract the most information about the cosmological parameters, we had to find not only the best methods and models for data analysis but also the optimal combination of these measurements.”

This analysis has now born fruit: the BOSS data show that dark energy, which is driving the cosmological expansion, is consistent with a cosmological constant within an error of only 5%. This constant, called Lambda, was introduced by Albert Einstein to counter the attractive force of matter, i.e. it has a repellent effect. Moreover, all results are fully consistent with the standard cosmological model, giving further strength to this still relatively young theory.

In particular, the map also reveals the distinctive signature of the coherent movement of galaxies toward regions of the Universe with more matter, due to the attractive force of gravity. Crucially, the observed amount of infall matches well to the predictions of general relativity. This supports the idea that the acceleration of the expansion rate is driven by a phenomenon at the largest cosmic scales, such as dark energy, rather than a breakdown of our gravitational theory.



Contact:

Saito, Shun
Phone: 2225
Email: ssaito@mpa-garching.mpg.de

Hämmerle, Hannelore
Hämmerle, Hannelore
Press officer
Phone: 3980
Email: hanne@mpa-garching.mpg.de



Original Publication 

1. Jan Niklas Grieb, Ariel G. Sánchez, Salvador Salazar-Albornoz et al. (the BOSS collaboration)
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Cosmological implications of the Fourier space wedges of the final sample
submitted to MNRAS
Source

2. Salvador Salazar-Albornoz, Ariel G. Sanchez, Jan Niklas Grieb et al.
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Angular clustering tomography and its cosmological implications
submitted to MNRAS
Source

3. Ariel G. Sanchez, Jan Niklas Grieb, Salvador Salazar-Albornoz et al.
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: combining correlated Gaussian posterior distributions
submitted to MNRAS
Source

4. Ariel G. Sanchez, Roman Scoccimarro, Martin Crocce et al.
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological implications of the configuration-space clustering wedges
submitted to MNRAS
Source

5. Florian Beutler, Hee-Jong Seo, Shun Saito et al.
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Anisotropic galaxy clustering The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in Fourier-space
submitted to MNRAS
Source

Wednesday, July 20, 2016

NASA's Hubble Telescope Makes First Atmospheric Study of Earth-Sized Exoplanets

Artist's View of Planets Transiting Red Dwarf Star in TRAPPIST-1 System  
Illustration Credit: NASA, ESA, and G. Bacon (STScI)
Science Credit: NASA, ESA, and J. de Wit (MIT)


Using NASA's Hubble Space Telescope, astronomers have conducted the first search for atmospheres around temperate, Earth-sized planets beyond our solar system and found indications that increase the chances of habitability on two exoplanets.

Specifically, they discovered that the exoplanets TRAPPIST-1b and TRAPPIST-1c, approximately 40 light-years away, are unlikely to have puffy, hydrogen-dominated atmospheres usually found on gaseous worlds.

"The lack of a smothering hydrogen-helium envelope increases the chances for habitability on these planets," said team member Nikole Lewis of the Space Telescope Science Institute (STScI) in Baltimore, Maryland. "If they had a significant hydrogen-helium envelope, there is no chance that either one of them could potentially support life because the dense atmosphere would act like a greenhouse."

Julien de Wit of the Massachusetts Institute of Technology in Cambridge, Massachusetts, led a team of scientists to observe the planets in near-infrared light using Hubble's Wide Field Camera 3. They used spectroscopy to decode the light and reveal clues to the chemical makeup of an atmosphere. While the content of the atmospheres is unknown and will have to await further observations, the low concentration of hydrogen and helium has scientists excited about the implications.

"These initial Hubble observations are a promising first step in learning more about these nearby worlds, whether they could be rocky like Earth, and whether they could sustain life," said Geoff Yoder, acting associate administrator for NASA's Science Mission Directorate in Washington, D.C. "This is an exciting time for NASA and exoplanet research."

The planets orbit a red dwarf star at least 500 million years old, in the constellation of Aquarius. They were discovered in late 2015 through a series of observations by the TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST), a Belgian robotic telescope located at the European Southern Observatory’s (ESO’s) La Silla Observatory in Chile.

TRAPPIST-1b completes a circuit around its red dwarf star in 1.5 days and TRAPPIST-1c in 2.4 days. The planets are between 20 and 100 times closer to their star than Earth is to the sun. Because their star is so much fainter than our sun, researchers think that at least one of the planets, or possibly both, may be within the star's habitable zone, where moderate temperatures could allow for liquid water to pool.

On May 4, astronomers took advantage of a rare simultaneous transit, when both planets crossed the face of their star within minutes of each other, to measure starlight as it filtered through any existing atmosphere. This double-transit, which occurs only every two years, provided a combined signal that offered simultaneous indicators of the atmospheric characteristics of the planets.

The researchers hope to use Hubble to conduct follow-up observations to search for thinner atmospheres, composed of elements heavier than hydrogen, like those of Earth and Venus.

"With more data, we could perhaps detect methane or see water features in the atmospheres, which would give us estimates of the depth of the atmospheres," said Hannah Wakeford, the paper's second author, at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Observations from future telescopes, including NASA's James Webb Space Telescope, will help determine the full composition of these atmospheres and hunt for potential biosignatures, such as carbon dioxide and ozone, in addition to water vapor and methane. Webb also will analyze a planet's temperature and surface pressure — key factors in assessing its habitability.

These planets are the first Earth-sized worlds found in the Search for habitable Planets EClipsing ULtra-cOOl Stars (SPECULOOS) survey, which will search more than 1,000 nearby red dwarf stars for Earth-sized worlds. So far, the survey has analyzed only 15 of those stars.

"These Earth-sized planets are the first worlds that astronomers can study in detail with current and planned telescopes to determine whether they are suitable for life," said de Wit. "Hubble has the ability to play the central atmospheric pre-screening role to tell astronomers which of these Earth-sized planets are prime candidates for more detailed study with the Webb telescope."

The results of the study appear in the July 20 issue of the journal Nature.

Contact

Felicia Chou
NASA Headquarters, Washington, D.C
202-358-0257
felicia.chou@nasa.gov

Donna Weaver / Ray Villard
Space Telescope Science Institute, Baltimore, Maryland
410-338-4493 / 410-338-4514
dweaver@stsci.edu / villard@stsci.edu

Julien de Wit
Massachusetts Institute of Technology, Cambridge, Massachusetts
jdewitt@mit.edu

Hannah Wakeford
NASA Goddard Spaceflight Center, Greenbelt, Maryland
301-286-7975
hannah.wakeford@nasa.gov

Nikole Lewis
Space Telescope Science Institute, Baltimore, Maryland
410-338-4820
nlewis@stsci.edu

Source: HubbleSite

Beyond the Kuiper Belt Edge

Kuiper Belt objects (KBOs) - 2014 FZ7 and 2015 FJ345
Image Credit: Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute (JHUAPL/SwRI) & S. Sheppard, et. al.

Animation of Kuiper Belt Object 2014 FZ71 created from the discovery images. 
Each image in the sequence was taken approximately three hours apart. Image 
Credit: Scott S. Sheppard/Chad Trujillo/DECam


Two new Kuiper Belt objects, 2014 FZ71 and 2015 FJ345, are among the most distant bodies in the Solar System. They are always further than 50AU from the Sun, and only Sedna and 2012 VP113 have larger perihelia. The discovery was made using data from DECam on the Blanco 4-m telescope at CTIO.

The new trans-Neptunian objects were discovered by Scott Sheppard, Chad Trujillo, and David Tholen in their search for objects beyond the outer edge of the Kuiper Belt (at about 50 AU). Unlike the more extreme Sedna and 2012 VP113, the new objects have moderate eccentricities. All the new moderately eccentric objects beyond the Kuiper Belt edge are near strong Neptune mean motion resonances. These new moderately eccentric objects likely obtained their unusual orbits through a combined interaction between Neptune’s mean motion resonance and the Kozai resonance. The discovery images for 2014 FZ71, shown at right, were obtained on 24 March 2014. An arrow indicates the approximate position of 2014 FZ71, which moves relative to the background stars and galaxies in this sequence of 3 images taken approximately 3 hours apart. 



Tuesday, July 19, 2016

Gemini Observatory Instrumental in Exoplanet Harvest

Image montage showing the Maunakea Observatories, Kepler Space Telescope, and night sky with K2 Fields and discovered planetary systems (dots) overlaid. An international team of scientists discovered more than 100 planets based on images from Kepler operating in the ‘K2 Mission’. The team confirmed and characterized the planets using a suite of telescopes worldwide, including four on Maunakea (the twin telescopes of Keck Observatory, the Gemini­North Telescope, and the Infrared Telescope Facility). The planet image on the right is an artist’s impression of a representative planet.  Image Credit: Art by Karen Teramura (UHIfA) based on night sky image of the ecliptic plane by Miloslav Druckmüller and Shadia Habbal, and Kepler Telescope and planet images by NASA. Full resolution JPEG


Gemini Observatory plays a key role in the latest harvest of over 100 confirmed exoplanets from NASA’s K2 mission, the repurposed Kepler spacecraft. Three instruments on the Gemini North telescope delivered precise images verifying many of the candidate stars as planetary system hosts. Researchers note that these systems could contain a considerable number of rocky, potentially earthlike exoplanets.

The Gemini North telescope on Hawaii’s Maunakea helped verify many of the over 100 new worlds announced in the initial crop of discoveries from the NASA K2 mission, according to Ian Crossfield of the University of Arizona. Crossfield led the international team of scientists who announced the findings, which are published online in The Astrophysical Journal Supplement Series. A preprint of the paper is available here.

“Gemini North was instrumental because it delivered extremely high-resolution images of over 70 of the almost 200 potential planetary systems that K2 uncovered,” says Crossfield. ”In total we used three instruments, or cameras, on Gemini to complete our studies – so you could say that Gemini was instrumental in that way too!”

Once K2’s data are analyzed to identify potential exoplanet candidates, many of the world’s most powerful telescopes, like Gemini, are set into motion. This is so astronomers can rule out other explanations that can produce the signature of a planet orbiting a star. “This is where the discovery happens,” says astronomer Christopher Davis of the US National Science Foundation, which funds over 70% of Gemini. “Once other possibilities are eliminated, like nearby background stars, the team can say with extreme certainty that we have a new exoplanet system.”

One of the instruments used at Gemini is a visiting instrument called the Differential Speckle Survey Instrument (DSSI) which is led by Steve Howell of NASA’s Ames Research Center. “These observations are a critical part of the exoplanet validation process,” says Howell. “It’s essentially the only way to validate small, earth-sized planets orbiting around other stars.” Howell’s DSSI instrument uses many extremely short (typically about 60 millisecond) exposures of a star to capture fine detail by combining the images and subtracting momentary distortions caused by the Earth’s atmosphere. With this technique astronomers can see details at, or very near, the theoretical limit of the 8-meter Gemini mirror which is like being able to resolve two automobile headlights at a distance of about 2000 miles.

In its initial mission, Kepler surveyed just one patch of sky in the northern hemisphere, measuring the frequency with which planets whose size and temperature are similar to Earth occur around stars like our Sun. But when the satellite lost its ability to precisely stare at its original target area in 2013, a brilliant fix created a second life for the telescope that is proving remarkably fruitful.

The new K2 mission provides fields of view within the ecliptic which presents greater opportunities for Earth-based observatories in both the northern and southern hemispheres. Additionally, the new mission opened up the observations to the entire scientific community, not just specific targets picked by science team members. K2 now looks at new types of populations, including a larger fraction of cooler, smaller, red dwarf-type stars, which are much more common in our Milky Way than Sun-like stars. The space observatory discovers new planets by measuring the subtle dip in a star's brightness caused by a planet passing in front of its star.

The Gemini followup observations were made as part of what is called a Large and Long program intended to provide access to Gemini for studies requiring more observing time, or extended periods of observations to yield high-impact results. In addition to observations with DSSI, Gemini’s Near-InfraRed Imager (NIRI) with the Altair adaptive optics system, and the Gemini Near-InfraRed Spectrograph (GNIRS) were used to make the verification observations.

In addition to Gemini, follow-up ground-based observations were made by W. M. Keck Observatory also on Maunakea in Hawai‘i, the Automated Planet Finder of the University of California Observatories, and the Large Binocular Telescope operated by the University of Arizona.


Institute for Astronomy, University of Hawaii press release.

W. M. Keck Observatory press release.


Media Contacts:

Peter Michaud
Public Information and Outreach
Gemini Observatory, Hilo, HI
Email:
pmichaud@gemini.edu
Cell: (808) 936-6643

 
Alexis-Ann Acohido
Public Information and Outreach
Gemini Observatory, Hilo, HI
Email:
aacohido@gemini.edu
Phone: (808) 974-2528

 
Doug Carroll
Director of Media Relations and Communications
University of Arizona
Email:
dougcarroll@email.arizona.edu
Phone: (520) 621-9017


Science Contacts:

Ian Crossfield
University of Arizona & UC Santa Cruz
Email:
ianc@ucsc.edu
Phone: (949) 923-0578

Steve Howell
Project Scientist, Kepler and K2 Mission
NASA Ames Research Center
Moffett Field, CA 94035
Email: steve.b.howell@nasa.gov
Desk: (650) 604-4238

Three Supernova Shells Around a Young Star Cluster

Expansion maps of the three detected bubbles, which show the detected expansion velocity in each pixel, all in the same velocity scale. Overlaid are contours of the region's Hydrogen alpha emission; it can be seen that the bubbles are roughly concentric with each other and the region. Figure extracted from Camps Fariña et al. (2016). Large format: JPEG


A group of astronomers, led by researchers at the Instituto de Astrofísica de Canarias (IAC), has found the first known case of three supernova remnants one inside the other. Using a method developed within the group for detecting huge expanding bubbles of gas in interstellar space, they were observing the galaxy M33 in our Local Group of galaxies and found an example of a triple-bubble. The results help to understand the feedback phenomenon, a fundamental process controlling star formation and the dissemination of metals produced in massive stars. 

The group has been building up a database of these superbubbles with observations of a number of galaxies and, using the very high resolution 2D spectrograph GHaFaS (Galaxy Halpha Fabry-Perot System) on the William Herschel Telescope (WHT), has been able to detect and measure some tens of them in different galaxies, which range in size from a few light years to as big as a thousand light years across. 

Superbubbles around large young star clusters are known to have a complex structure due to the effects of powerful stellar winds and supernova explosions of individual stars, whose separate bubbles may end up merging into a superbubble, but this is the first time that they, or any other observers, have found three concentric expanding supernova shells. They are concentric because the supernovae which produced them exploded at intervals of only 10,000 years, close to simultaneously on astronomical timescales, so they are still relatively spherical and surround their parent star cluster. 

"This phenomenon—says John Beckman, one of the co-authors on the paper—allows us to explore the interstellar medium in a unique way, we can measure how much matter there is in a shell, approximately a couple of hundred times the mass of the sun in each of the shells". However, if it is known that a supernova expels only around ten times the mass of the sun, where do the second and third shells get their gas from if the first supernova sweeps up all the gas? 

The answer to that must come from the structure of the surrounding gas: the inhomogeneous interstellar medium. "It must be—says Artemi Camps Fariña, who is first author on the paper—that the interstellar medium is not at all uniform, there must be dense clumps of gas, surrounded by space with gas at a much lower density. A supernova does not just sweep up gas, it evaporates the outsides of the clumps, leaving some dense gas behind which can make the second and the third shells". 

"The presence of the bubbles—adds Artemi— explains why star formation on cosmological timescales has been much slower than simple models of galaxy evolution predicted. These bubbles are part of a widespread feedback process in galaxy discs and if it were not for feedback, spiral galaxies would have very short lives, and our own existence would be improbable", concludes. The idea of an inhomogeneous interstellar medium is not new, but the triple bubble gives a much clearer and quantitative view of the structure and the feedback process. The results will help theorists working on feedback to a better understanding of how this process works in all galaxy discs. 

More Information:

A. Camps Fariña, J. E. Beckman, J. Font, A. Borlaff, J. Zaragoza, P. Amram, 2016, "Three supernova shells around a young star cluster in M33", MNRAS, 461, L87. DOI: 10.1093/mnrasl/slw106. Paper on MNRAS | arXiv


Contact:  

Javier Méndez   
(Public Relations Officer)



Monday, July 18, 2016

Black Hole Makes Material Wobble Around It News Media Contact

This artist's impression depicts the accretion disc surrounding a black hole, in which the inner region of the disc precesses.
› Full image and caption


The European Space Agency's orbiting X-ray observatory, XMM-Newton, has proved the existence of a "gravitational vortex" around a black hole. The discovery, aided by NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) mission, solves a mystery that has eluded astronomers for more than 30 years, and will allow them to map the behavior of matter very close to black holes. It could also open the door to future investigations of Albert Einstein's general relativity.

Matter falling into a black hole heats up as it plunges to its doom. Before it passes into the black hole and is lost from view forever, it can reach millions of degrees. At that temperature it shines X-rays into space.

In the 1980s, pioneering astronomers using early X-ray telescopes discovered that the X-rays coming from stellar-mass black holes in our galaxy flicker. The changes follow a set pattern. When the flickering begins, the dimming and re-brightening can take 10 seconds to complete. As the days, weeks and then months progress, the period shortens until the oscillation takes place 10 times every second. Then, the flickering suddenly stops altogether.

The phenomenon was dubbed the Quasi Periodic Oscillation (QPO). "It was immediately recognized to be something fascinating because it is coming from something very close to a black hole," said Adam Ingram, University of Amsterdam, the Netherlands, who began working to understand QPOs for his doctoral thesis in 2009.

During the 1990s, astronomers had begun to suspect that the QPOs were associated with a gravitational effect predicted by Einstein's general relativity: that a spinning object will create a kind of gravitational vortex.
"It is a bit like twisting a spoon in honey. Imagine that the honey is space and anything embedded in the honey will be "dragged" around by the twisting spoon," explained Ingram.  "In reality, this means that anything orbiting a spinning object will have its motion affected." In the case of an inclined orbit, it will "precess." This means that the whole orbit will change orientation around the central object. The time for the orbit to return to its initial condition is known as a precession cycle.

In 2004, NASA launched Gravity Probe B to measure this so-called Lense-Thirring effect around Earth. After painstaking analysis, scientists confirmed that the spacecraft would turn through a complete precession cycle once every 33 million years.

Around a black hole, however, the effect would be much more noticeable because of the stronger gravitational field. The precession cycle would take just a matter of seconds or less to complete. This is so close to the periods of the QPOs that astronomers began to suspect a link.

Ingram began working on the problem by looking at what happened in the flat disc of matter surrounding a black hole. Known as an accretion disc, it is the place where material gradually spirals inwards towards the black hole. Scientists had already suggested that, close to the black hole, the flat accretion disc puffs up into a hot plasma, in which electrons are stripped from their host atoms. Termed the hot inner flow, it shrinks in size over weeks and months as it is eaten by the black hole. Together with colleagues, Ingram published a paper in 2009 suggesting that the QPO is driven by the Lense-Thirring precession of this hot flow. This is because the smaller the inner flow becomes, the closer to the black hole it would approach and so the faster its Lense-Thirring precession cycle would be. The question was: how to prove it?

"We have spent a lot of time trying to find smoking gun evidence for this behavior," said Ingram.

The answer is that the inner flow is releasing high-energy radiation that strikes the matter in the surrounding accretion disc, making the iron atoms in the disc shine like a fluorescent light tube. The iron releases X-rays of a single wavelength -- referred to as "a spectral line."

Because the accretion disc is rotating, the iron line has its wavelength distorted by the Doppler effect. Line emission from the approaching side of the disc is squashed -- blue shifted -- and line emission from the receding disc material is stretched -- red shifted. If the inner flow really is precessing, it will sometimes shine on the approaching disc material and sometimes on the receding material, making the line wobble back and forth over the course of a precession cycle.

Seeing this wobbling is where XMM-Newton came in. Ingram and colleagues from Amsterdam, Cambridge, Southampton and Tokyo applied for a long-duration observation that would allow them to watch the QPO repeatedly. They chose black hole H 1743-322, which was exhibiting a four-second QPO at the time. They watched it for 260,000 seconds with XMM-Newton. They also observed it for 70,000 seconds with NASA's NuSTAR X-ray observatory.

"The high-energy capability of NuSTAR was very important," Ingram said. "NuSTAR confirmed the wobbling of the iron line, and additionally saw a feature in the spectrum called a 'reflection hump' that added evidence for precession."

After a rigorous analysis process of adding all the observational data together, they saw that the iron line was wobbling in accordance with the predictions of general relativity. "We are directly measuring the motion of matter in a strong gravitational field near to a black hole," says Ingram.

This is the first time that the Lense-Thirring effect has been measured in a strong gravitational field. The technique will allow astronomers to map matter in the inner regions of accretion discs around black holes. It also hints at a powerful new tool with which to test general relativity.

Einstein's theory is largely untested in such strong gravitational fields. So if astronomers can understand the physics of the matter that is flowing into the black hole, they can use it to test the predictions of general relativity as never before - but only if the movement of the matter in the accretion disc can be completely understood.

"If you can get to the bottom of the astrophysics, then you can really test the general relativity," says Ingram. A deviation from the predictions of general relativity would be welcomed by a lot of astronomers and physicists. It would be a concrete signal that a deeper theory of gravity exists.

Larger X-ray telescopes in the future could help in the search because they are more powerful and could more efficiently collect X-rays. This would allow astronomers to investigate the QPO phenomenon in more detail. But for now, astronomers can be content with having seen Einstein's gravity at play around a black hole.

"This is a major breakthrough since the study combines information about the timing and energy of X-ray photons to settle the 30-year debate around the origin of QPOs. The photon-collecting capability of XMM-Newton was instrumental in this work," said Norbert Schartel, ESA Project Scientist for XMM-Newton.


More Information

The results reported in this article are published in the Monthly Notices of the Royal Astronomical Society.

The European Space Agency's X-ray Multi-Mirror Mission, XMM-Newton, was launched in December 1999. The largest scientific satellite to have been built in Europe, it is also one of the most sensitive X-ray observatories ever flown. More than 170 wafer-thin, cylindrical mirrors direct incoming radiation into three high-throughput X-ray telescopes. XMM-Newton's orbit takes it almost a third of the way to the moon, allowing for long, uninterrupted views of celestial objects.

NuSTAR is a Small Explorer mission led by Caltech in Pasadena and managed by NASA's Jet Propulsion Laboratory, also in Pasadena, for NASA's Science Mission Directorate in Washington.


For more information about NuSTAR, visit: http://www.nasa.gov/nustar -  http://www.nustar.caltech.edu




News Media Contact

Elizabeth Landau
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-6425

elizabeth.landau@jpl.nasa.gov

Adam Ingram
Anton Pannekoek Institute for Astronomy
University of Amsterdam
The Netherlands

a.r.ingram@uva.nl

Norbert Schartel
ESA XMM-Newton Project Scientist
Directorate of Science
European Space Agency
+34-91-8131-184

Norbert.Schartel@esa.int


Written by Karen O'Flaherty
European Space Agency


Source: JPL- Caltech

Friday, July 15, 2016

GRB 140903A: Chandra Finds Evidence for Violent Stellar Merger

GRB 140903A
Credit  X-ray: NASA/CXC/Univ. of Maryland/E. Troja et al, 
Optical: Lowell Observatory's Discovery Channel Telescope/E.Troja et al. 
Illustration: NASA/CXC/M.Weiss 

JPEG (732.8 kb) - Large JPEG (7.1 MB)  - Tiff (65.1 MB) - More Images 

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Tour of GRB 140903A

animation



Gamma-ray bursts, or GRBs, are some of the most violent and energetic events in the Universe. Although these events are the most luminous explosions in the universe, a new study using NASA's Chandra X-ray Observatory, NASA's Swift satellite and other telescopes suggests that scientists may be missing a majority of these powerful cosmic detonations.

Astronomers think that some GRBs are the product of the collision and merger of two neutron stars or a neutron star and a black hole. The new research gives the best evidence to date that such collisions will generate a very narrow beam, or jet, of gamma rays. If such a narrow jet is not pointed toward Earth, the GRB produced by the collision will not be detected.

Collisions between two neutron stars or a neutron star and black hole are expected to be strong sources of gravitational waves that could be detected whether or not the jet is pointed towards the Earth. Therefore, this result has important implications for the number of events that will be detectable by the Laser Interferometry Gravitational-Wave Observatory (LIGO) and other gravitational wave observatories.

On September 3, 2014, NASA's Swift observatory picked up a GRB - dubbed GRB 140903A due to the date it was detected. Scientists used optical observations with the Gemini Observatory telescope in Hawaii to determine that GRB 140903A was located in a galaxy about 3.9 billion light years away, relatively nearby for a GRB.

The large panel in the graphic is an illustration showing the aftermath of a neutron star merger, including the generation of a GRB. In the center is a compact object - either a black hole or a massive neutron star - and in red is a disk of material left over from the merger, containing material falling towards the compact object. Energy from this infalling material drives the GRB jet shown in yellow. In orange is a wind of particles blowing away from the disk and in blue is material ejected from the compact object and expanding at very high speeds of about one tenth the speed of light.

The image on the left of the two smaller panels shows an optical view from the Discovery Channel Telescope (DCT) with GRB 140903A in the middle of the square and a close-up X-ray view from Chandra on the right. The bright star in the optical image is unrelated to the GRB.

The gamma-ray blast lasted less than two seconds. This placed it into the "short GRB" category, which astronomers think are the output from neutron star-neutron star or black hole-neutron star collisions eventually forming either a black hole or a neutron star with a strong magnetic field. (The scientific consensus is that GRBs that last longer than two seconds result from the collapse of a massive star.)

About three weeks after the Swift discovery of GRB 140903A, a team of researchers led by Eleonora Troja of the University of Maryland, College Park (UMD), observed the aftermath of the GRB in X-rays with Chandra. Chandra observations of how the X-ray emission from this GRB decreases over time provide important information about the properties of the jet.

Specifically, the researchers found that the jet is beamed into an angle of only about five degrees based on the X-ray observations, plus optical observations with the Gemini Observatory and the DCT and radio observations with the National Science Foundation's Karl G. Jansky Very Large Array. This is roughly equivalent to a circle with the diameter of your three middle fingers held at arms length. This means that astronomers are detecting only about 0.4% of this type of GRB when it goes off, since in most cases the jet will not be pointed directly at us.

Previous studies by other astronomers had suggested that these mergers could produce narrow jets. However, the evidence in those cases was not as strong because the rapid decline in light was not observed at multiple wavelengths, allowing for explanations not involving jets.

Several pieces of evidence link this event to the merger of two neutron stars, or between a neutron star and black hole. These include the properties of the gamma ray emission, the old age and the low rate of stars forming in the GRB's host galaxy and the lack of a bright supernova. In some previous cases strong evidence for this connection was not found.

New studies have suggested that such mergers could be the production site of elements heavier than iron, such as gold. Therefore, the rate of these events is also important to estimate the total amount of heavy elements produced by these mergers and compare it with the amounts observed in the Milky Way galaxy.

A paper describing these results was recently accepted for publication in The Astrophysical Journal and is available online. The first author of this paper is Eleonora Troja and the co-authors are T. Sakamoto (Aoyama Gakuin University, Japan), S.Cenko (GSFC), A. Lien (University of Maryland, Baltimore), N. Gehrels (GSFC), A. Castro-Tirado (IAA-CSIC, Spain), R. Ricci (INAF-Istituto di Radioastronomia, Italy), J. Capone, V. Toy, & A. Kutyrev (UMD), N. Kawai (Tokyo Institute of Technology, Japan), A. Cucchiara (GSFC), A. Fruchter (STScI), J.Gorosabel (UMD), S. Jeong (IAA-CSIC), A. Levan (University of Warwick, UK), D. Perley (University of Copenhagen, Denmark), R.Sanchez-Ramirez (Instituto de Astrof ́ısica de Andaluc ́ıa, Spain), N.Tanvir (University of Leicester, UK), S. Veilleux (UMD).

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.



Fast Facts for GRB 140903A:

Scale: X-ray image is 15 arcsec across (about 244,00 light years)
Category: Miscellaneous Objects, Black Holes
Coordinates (J2000): RA 15h 52m 03.27s | Dec +27° 36' 09.30"
Constellation: Corona Borealis
Observation Date: 06 Sep and 18 Sep 2014
Observation Time: 22 hours 13 min.
Obs. ID: 15873, 15986
Instrument: ACIS
References: Troja, E. et al, 2016, ApJ (accepted); arXiv:1605.03573
Color Code: X-ray (Blue), Optical (Yellow)
Distance Estimate: About 3.9 billion light years (z=0.351)



A lonely birthplace

Credit: ESA/Hubble & NASA and N. Grogin (STScI)


This image was taken by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS), and shows a starburst galaxy named MCG+07-33-027. This galaxy lies some 300 million light-years away from us, and is currently experiencing an extraordinarily high rate of star formation — a starburst. Normal galaxies produce only a couple of new stars per year, but starburst galaxies can produce a hundred times more than that! As MCG+07-33-027 is seen face-on, the galaxy’s spiral arms and the bright star-forming regions within them are clearly visible and easy for astronomers to study. 

In order to form newborn stars, the parent galaxy has to hold a large reservoir of gas, which is slowly depleted to spawn stars over time. For galaxies in a state of starburst, this intense period of star formation has to be triggered somehow — often this happens due to a collision with another galaxy. 

MCG+07-33-027, however, is special; while many galaxies are located within a large cluster of galaxies, MCG+07-33-027 is a field galaxy, which means it is rather isolated. Thus, the triggering of the starburst was most likely not due to a collision with a neighbouring or passing galaxy and astronomers are still speculating about the cause.


Thursday, July 14, 2016

Stellar Outburst Brings Water Snow Line Into View

Artist’s impression of the water snowline around the young star V883 Orionis

ALMA image of the protoplanetary disc around V883 Orionis

The star V883 Orionis in the constellation of Orion

Shifting water snowline in V883 Orionis

PR Image eso1626e
ALMA image of the protoplanetary disc around V883 Orionis (annotated)



Videos

ALMA image of the protoplanetary disc around V883 Orionis
ALMA image of the protoplanetary disc around V883 Orionis

Zooming on the protoplanetary disc around V883 Orionis
Zooming on the protoplanetary disc around V883 Orionis

The protoplanetary disc around V883 Orionis (artist's impression)
The protoplanetary disc around V883 Orionis (artist's impression) 




The Atacama Large Millimeter/submillimeter Array (ALMA) has made the first ever resolved observation of a water snow line within a protoplanetary disc. This line marks where the temperature in the disc surrounding a young star drops sufficiently low for snow to form. A dramatic increase in the brightness of the young star V883 Orionis flash heated the inner portion of the disc, pushing the water snow line out to a far greater distance than is normal for a protostar, and making it possible to observe it for the first time. The results are published in the journal Nature on 14 July 2016.

Young stars are often surrounded by dense, rotating discs of gas and dust, known as protoplanetary discs, from which planets are born. The heat from a typical young solar-type star means that the water within a protoplanetary disc is gaseous up to distances of around 3 au from the star [1] — less than 3 times the average distance between the Earth and the Sun — or around 450 million kilometres [2]. Further out, due to the extremely low pressure, the water molecules transition directly from a gaseous state to form a patina of ice on dust grains and other particles. The region in the protoplanetary disc where water transitions between the gas and solid phases is known as the water snow line [3].

But the star V883 Orionis is unusual. A dramatic increase in its brightness has pushed the water snow line out to a distance of around 40 au (about 6 billion kilometres or roughly the size of the orbit of the dwarf planet Pluto in our Solar System). This huge increase, combined with the resolution of ALMA at long baselines [4], has allowed a team led by Lucas Cieza (Millennium ALMA Disk Nucleus and Universidad Diego Portales, Santiago, Chile) to make the first ever resolved observations of a water snow line in a protoplanetary disc.

The sudden brightening that V883 Orionis experienced is an example of what occurs when large amounts of material from the disc surrounding a young star fall onto its surface. V883 Orionis is only 30% more massive than the Sun, but thanks to the outburst it is experiencing, it is currently a staggering 400 times more luminous — and much hotter [5].

Lead author Lucas Cieza explains: “The ALMA observations came as a surprise to us. Our observations were designed to look for disc fragmentation leading to planet formation. We saw none of that; instead, we found what looks like a ring at 40 au. This illustrates well the transformational power of ALMA, which delivers exciting results even if they are not the ones we were looking for.”

The bizarre idea of snow orbiting in space is fundamental to planet formation. The presence of water ice regulates the efficiency of the coagulation of dust grains — the first step in planet formation. Within the snow line, where water is vapourised, smaller, rocky planets like our own are believed to form. Outside the water snow line, the presence of water ice allows the rapid formation of cosmic snowballs, which eventually go on to form massive gaseous planets such as Jupiter.

The discovery that these outbursts may blast the water snow line to about 10 times its typical radius is very significant for the development of good planetary formation models. Such outbursts are believed to be a stage in the evolution of most planetary systems, so this may be the first observation of a common occurrence. In that case, this observation from ALMA could contribute significantly to a better understanding of how planets throughout the Universe formed and evolved.



Notes

[1] ] 1 au, or one astronomical unit, is the mean distance between the Earth and the Sun, around 149.6 million kilometres.This unit is typically used to describe distances measured within the Solar System and planetary systems around other stars.

[2] This line was between the orbits of Mars and Jupiter during the formation of the Solar System, hence the rocky planets Mercury, Venus, Earth and Mars formed within the line, and the gaseous planets Jupiter, Saturn, Uranus and Neptune formed outside.

[3] The snow lines for other molecules, such as carbon monoxide and methane, have been observed previously with ALMA, at distances of greater than 30 au from the protostar within other protoplanetary discs. Water freezes at a relatively high temperature and this means that the water snow line is usually much too close to the protostar to observe directly.

[4] Resolution is the ability to discern that objects are separate. To the human eye, several bright torches at a distance would seem like a single glowing spot, and only at closer quarters would each torch be distinguishable. The same principle applies to telescopes, and these new observations have exploited the exquisite resolution of ALMA in its long baseline modes. The resolution of ALMA at the distance of V883 Orionis is about 12 au — enough to resolve the water snow line at 40 au in this outbursting system, but not for a typical young star.

[5] Stars like V883 Orionis are classed as FU Orionis stars, after the original star that was found to have this behaviour. The outbursts may last for hundreds of years.



More Information


This research was presented in a paper entitled “Imaging the water snow-line during a protostellar outburst”, by L. Cieza et al., to appear in Nature on 14 July 2016.

The team is composed of Lucas A. Cieza (Millennium ALMA Disk Nucleus; Universidad Diego Portales, Santiago, Chile), Simon Casassus (Universidad de Chile, Santiago, Chile), John Tobin (Leiden Observatory, Leiden University, The Netherlands), Steven Bos (Leiden Observatory, Leiden University, The Netherlands), Jonathan P. Williams (University of Hawaii at Manoa, Honolulu, Hawai`i, USA), Sebastian Perez (Universidad de Chile, Santiago, Chile), Zhaohuan Zhu (Princeton University, Princeton, New Jersey, USA), Claudio Cáceres (Universidad Valparaiso, Valparaiso, Chile), Hector Canovas (Universidad Valparaiso, Valparaiso, Chile), Michael M. Dunham (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), Antonio Hales (Joint ALMA Observatory, Santiago, Chile), Jose L. Prieto (Universidad Diego Portales, Santiago, Chile), David A. Principe (Universidad Diego Portales, Santiago, Chile), Matthias R. Schreiber (Universidad Valparaiso, Valparaiso, Chile), Dary Ruiz-Rodriguez (Australian National University, Mount Stromlo Observatory, Canberra, Australia) and Alice Zurlo (Universidad Diego Portales & Universidad de Chile, Santiago, Chile).
v The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

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

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



Links



Contacts

Lucas Cieza
Universidad Diego Portales
Santiago, Chile
Tel: +56 22 676 8154
Cell: +56 95 000 6541
Email: lucas.cieza@mail.udp.cl

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


Source: ESO