Infrared Astronomy Archives

March 3, 2014December 23, 2015 by Jason Major

SOFIA Gives Scientists a First-Class View of a Supernova

This Image of M82 including a supernova at near-infrared wavelengths J, H, and K (1.2, 1.65, and 2.2 microns), made Feb. 20 by the FLITECAM instrument on SOFIA. (NASA/SOFIA/FLITECAM team/S. Shenoy)

Astronomers wanting a closer look at the recent Type Ia supernova that erupted in M82 back in January are in luck. Thanks to NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) near-infrared observations have been made from 43,000 feet — 29,000 feet higher than some of the world’s loftiest ground-based telescopes.

(And, technically, that is closer to M82. If only just a little.)

All sarcasm aside, there really is a benefit from that extra 29,000 feet. Earth’s atmosphere absorbs a lot of wavelengths of the electromagnetic spectrum, especially in the infrared and sub-millimeter ranges. So in order to best see what’s going on in the Universe in these very active wavelengths, observational instruments have to be placed in very high, dry (and thus also very remote) locations, sent entirely out into space, or, in the case of SOFIA, mounted inside a modified 747 where they can simply be flown above 99% of the atmosphere’s absorptive water vapor.

NASA's airborne SOFIA observatory (SOFIA/USRA) — NASA’s airborne SOFIA observatory (SOFIA/USRA)

During a recent 10-hour flight over the Pacific, researchers aboard SOFIA turned their attention to SN2014J, one of the closest Type Ia “standard candle” supernovas that have ever been seen. It appeared suddenly in the relatively nearby Cigar Galaxy (M82) in mid-January and has since been an exciting target of observation for scientists and amateur skywatchers alike.

In addition to getting a bird’s-eye-view of a supernova, they used the opportunity to calibrate and test the FLITECAM (First Light Infrared Test Experiment CAMera) instrument, a near infrared camera with spectrographic capabilities mounted onto SOFIA’s 2.5-meter German-built main telescope.

What they’ve found are the light signatures of heavy metals being ejected by the exploding star. (Rock on, SN2014J.)

“When a Type Ia supernova explodes, the densest, hottest region within the core produces nickel 56,” said Howie Marion from the University of Texas at Austin, a co-investigator aboard the flight. “The radioactive decay of nickel-56 through cobalt-56 to iron-56 produces the light we are observing tonight. At this life phase of the supernova, about one month after we first saw the explosion, the H- and K-band spectra are dominated by lines of ionized cobalt. We plan to study the spectral features produced by these lines over a period of time and see how they change relative to each other. That will help us define the mass of the radioactive core of the supernova.”

Three images of M82 and the supernova SN2014J, including one from the FLITECAM instrument on SOFIA (right). Credit: NASA/SOFIA/FLITECAM team/S. Shenoy

Further observations from SOFIA will help researchers learn more about the evolution of Type Ia supernovas, which in addition to being part of the life cycles of certain binary-pair stars are also valuable tools used by astronomers to determine distances to far-off galaxies.

Researchers work at the FLITECAM instrument station on board SOFIA on Feb. 20 (NASA/SOFIA/N. Veronico)

“To be able to observe the supernova without having to make assumptions about the absorption of the Earth’s atmosphere is great,” said Ian McLean, professor at UCLA and developer of FLITECAM. “You could make these observations from space as well, if there was a suitable infrared spectrograph to make those measurements, but right now there isn’t one. So this observation is something SOFIA can do that is absolutely unique and extremely valuable to the astronomical community.”

Source: SOFIA Science Center, NASA Ames

UPDATE 4 March 2014: The FY 2015 budget request proposed by the White House will effectively shelf the SOFIA mission, redirecting its funding toward planetary missions like Cassini and an upcoming Europa mission. Unfortunately, SOFIA’s flying days are now numbered, unless German partner DLR increases its contribution. Read more here.

February 28, 2014December 23, 2015 by Jason Major

NEOWISE Spots a “Weirdo” Comet

Infrared image of comet NEOWISE (C/2014 C3). Credit: NASA/JPL-Caltech

NASA’s NEOWISE mission — formerly known as just WISE — has identified the first comet of its new near-Earth object hunting career… and, according to mission scientists, it’s a “weirdo.”

In its former life NASA’s WISE (Wide-field Infrared Survey Explorer) spacecraft scanned the entire sky in infrared wavelengths. It helped discover the galaxy’s coldest stars, the Universe’s brightest galaxies, and some of the darkest asteroids lurking in the main asteroid belt between Mars and Jupiter… as well as closer in to Earth’s neck of the woods.

After exhausting its supply of liquid coolant needed to shield itself from its own radiating heat, in 2011 WISE was put into a state of hibernation. It was awoken last year and rebranded NEOWISE, and set upon the task of locating unknown objects with orbits in the proximity of Earth’s.

Kevin Luhman discovered the brown dwarf pair in data from NASA's Wide-field Infrared Survey Explorer (WISE; artist's impression). Image: NASA/JPL-Caltech — Artist’s impression of the WISE satellite

To date several new asteroids have already been found by NEOWISE, and on February 14, 2014, it spotted its first comet.

“We are so pleased to have discovered this frozen visitor from the outermost reaches of our solar system,” said Amy Mainzer, NEOWISE principal investigator at JPL. “This comet is a weirdo — it is in a retrograde orbit, meaning that it orbits the sun in the opposite sense from Earth and the other planets.”

Designated “C/2014 C3 (NEOWISE),” the comet was 143 million miles (230 million km) away in the image above — a composite made from six infrared exposures. That’s 585 times the distance to the Moon, or about the average distance between the Earth and Mars.

The tail of the comet NEOWISE extends about 25,000 miles (40,000 km) to the right in the image.

Overall, C/2014 C3 (NEOWISE) was spotted six times before it moved out of range of the spacecraft’s view. The comet has a highly-eccentric 20-year orbit that takes it high above the plane of the Solar System and out past the orbit of Jupiter. Technically, with a perihelion distance greater than 1.3 AU, comet C/2014 C3 does not classify as a near-Earth object (and its orbit does not intersect Earth’s.) But it’s still good to know that NEOWISE is looking out for us.

Read more on JPL’s NEOWISE site here, and see details on the comet’s orbit on the Minor Planet Center’s website here and from JPL’s Small-Body Database here.

Source: NASA/JPL

February 25, 2014December 23, 2015 by Jason Major

New Technique Finds Water in Exoplanet Atmospheres

Artist's concept of a hot Jupiter exoplanet orbiting a star similar to tau Boötes (Image used with permission of David Aguilar, Harvard-Smithsonian Center for Astrophysics)

As more and more exoplanets are identified and confirmed by various observational methods, the still-elusive “holy grail” is the discovery of a truly Earthlike world… one of the hallmarks of which is the presence of liquid water. And while it’s true that water has been identified in the thick atmospheres of “hot Jupiter” exoplanets before, a new technique has now been used to spot its spectral signature in yet another giant world outside our solar system — potentially paving the way for even more such discoveries.

Researchers from Caltech, Penn State University, the Naval Research Laboratory, the University of Arizona, and the Harvard-Smithsonian Center for Astrophysics have teamed up in an NSF-funded project to develop a new way to identify the presence of water in exoplanet atmospheres.

Previous methods relied on specific instances such as when the exoplanets — at this point all “hot Jupiters,” gaseous planets that orbit closely to their host stars — were in the process of transiting their stars as viewed from Earth.

This, unfortunately, is not the case for many extrasolar planets… especially ones that were not (or will not be) discovered by the transiting method used by observatories like Kepler.

Watch: Kepler’s Universe: More Planets in Our Galaxy Than Stars

So the researchers turned to another method of detecting exoplanets: radial velocity, or RV. This technique uses visible light to watch the motion of a star for the ever-so-slight wobble created by the gravitational “tug” of an orbiting planet. Doppler shifts in the star’s light indicate motion one way or another, similar to how the Doppler effect raises and lowers the pitch of a car’s horn as it passes by.

The two Keck 10-meter domes atop Mauna Kea. (Rick Peterson/WMKO)

But instead of using visible wavelengths, the team dove into the infrared spectrum and, using the Near Infrared Echelle Spectrograph (NIRSPEC) at the W. M. Keck Observatory in Hawaii, determined the orbit of the relatively nearby hot Jupiter tau Boötis b… and in the process used its spectroscopy to identify water molecules in its sky.

“The information we get from the spectrograph is like listening to an orchestra performance; you hear all of the music together, but if you listen carefully, you can pick out a trumpet or a violin or a cello, and you know that those instruments are present,” said Alexandra Lockwood, graduate student at Caltech and first author of the study. “With the telescope, you see all of the light together, but the spectrograph allows you to pick out different pieces; like this wavelength of light means that there is sodium, or this one means that there’s water.”

Previous observations of tau Boötis b with the VLT in Chile had identified carbon monoxide as well as cooler high-altitude temperatures in its atmosphere.

Now, with this proven IR RV technique, the atmospheres of exoplanets that don’t happen to cross in front of their stars from our point of view can also be scrutinized for the presence of water, as well as other interesting compounds.

“We now are applying our effective new infrared technique to several other non-transiting planets orbiting stars near the Sun,” said Chad Bender, a research associate in the Penn State Department of Astronomy and Astrophysics and a co-author of the paper. “These planets are much closer to us than the nearest transiting planets, but largely have been ignored by astronomers because directly measuring their atmospheres with previously existing techniques was difficult or impossible.”

Once the next generation of high-powered telescopes are up and running — like the James Webb Space Telescope, slated to launch in 2018 — even smaller and more distant exoplanets can be observed with the IR method… perhaps helping to make the groundbreaking discovery of a planet like ours.

“While the current state of the technique cannot detect earthlike planets around stars like the Sun, with Keck it should soon be possible to study the atmospheres of the so-called ‘super-Earth’ planets being discovered around nearby low-mass stars, many of which do not transit,” said Caltech professor of cosmochemistry and planetary sciences Geoffrey Blake. “Future telescopes such as the James Webb Space Telescope and the Thirty Meter Telescope (TMT) will enable us to examine much cooler planets that are more distant from their host stars and where liquid water is more likely to exist.”

The findings are described in a paper published in the February 24, 2014 online version of The Astrophysical Journal Letters.

Sources: Caltech and EurekAlert press releases.

February 21, 2014December 23, 2015 by Jason Major

Runaway Star Shocks the Galaxy!

The speeding rogue star Kappa Cassiopeiae sets up a glowing bow shock in this Spitzer image (NASA/JPL-Caltech)

That might seem like a sensational headline worthy of a supermarket tabloid but, taken in context, it’s exactly what’s happening here!

The bright blue star at the center of this image is a B-type supergiant named Kappa Cassiopeiae, 4,000 light-years away. As stars in our galaxy go it’s pretty big — over 57 million kilometers wide, about 41 times the radius of the Sun. But its size isn’t what makes K Cas stand out — it’s the infrared-bright bow shock it’s creating as it speeds past its stellar neighbors at a breakneck 1,100 kilometers per second.

K Cas is what’s called a runway star. It’s traveling very fast in relation to the stars around it, possibly due to the supernova explosion of a previous nearby stellar neighbor or companion, or perhaps kicked into high gear during a close encounter with a massive object like a black hole.

As it speeds through the galaxy it creates a curved bow shock in front of it, like water rising up in front of the bow of a ship. This is the ionized glow of interstellar material compressed and heated by K Cas’ stellar wind. Although it looks like it surrounds the star pretty closely in the image above, the glowing shockwave is actually about 4 light-years out from K Cas… slightly less than the distance from the Sun to Proxima Centauri.

The bow shock of Zeta Ophiuchi, another runaway star observed by Spitzer (NASA/JPL-Caltech)

Although K Cas is visible to the naked eye, its bow shock isn’t. It’s only made apparent in infrared wavelengths, which NASA’s Spitzer Space Telescope is specifically designed to detect. Some other runaway stars have brighter bow shocks — like Zeta Ophiuchi at right — which can be seen in optical wavelengths (as long as they’re not obscured by dust, which Zeta Oph is.)

The bright wisps seen crossing K Cas’ bow shock may be magnetic filaments that run throughout the galaxy, made visible through interaction with the ionized gas. In fact bow shocks are of particular interest to astronomers precisely because they help reveal otherwise invisible features and allow deeper investigation into the chemical composition of stars and the regions of the galaxy they are traveling through. Like a speeding car on a dark country road, runaway stars’ bow shocks are — to scientists — like high-beam headlamps lighting up the space ahead.

Runaway stars are not to be confused with rogue stars, which, although also feel the need for speed, have been flung completely out of their home galaxies.

Source: NASA

January 24, 2014December 23, 2015 by Elizabeth Howell

After A Long Nap, NEOWISE Springs Into Action With Asteroid Discoveries

Dots (circled) in this image show the first asteroid spotted by NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) after the mission came out of hibernation. Credit: NASA

If anything, NASA’s asteroid-hunting spacecraft seems to be refreshed after going into forced hibernation for 2.5 years. In the first 25 days since it started seeking small solar system bodies in earnest again, the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) found three new objects and detected an additional 854, NASA said Thursday (Jan. 23).

Luckily for people interested in this field, Amy Mainzer (the principal investigator for this mission) has been tweeting out discoveries as they come — and other observations besides. “Just passed our @WISE_Mission post-restart review. I believe the technical term is “Yee haw!!” she wrote Jan. 21. Below are a couple of illustrated examples of discoveries from her Twitter feed. Click on the pictures for larger versions.

In a release, NASA added that NEOWISE is “observing and characterizing” one NEO a day, which means not only looking at the object, but probing its size and composition. Astronomers know of about 10,500 NEOs, but of those only 10% (or about 1,500) have physical measurements cataloged as well. NEOWISE investigators aim to make hundreds of more of these measurements.

The mission (originally called WISE) launched in December 2009 to examine the universe in infrared light. After completely mapping the sky, it ran out of coolant it needed to do this work in 2010. It then shifted to examining comets and asteroids before being put into hibernation in February 2011. Read more about its mission history in this past Universe Today article.

December 12, 2013December 23, 2015 by Tammy Plotner

Argon – The First Noble Gas Molecules Discovered In Space

Messier 1 Hubble Image: Credit - NASA, ESA, J. Hester and A. Loll (Arizona State University)

There are only six of them: radon, helium, neon, krypton, xenon and the first molecules to be discovered in space – argon. They are all odorless, colorless, monatomic gases with very low chemical reactivity. So where did a team of astronomers using ESA’s Herschel Space Observatory make their rather unusual discovery? Try Messier 1… The “Crab” Nebula!

In a study led by Professor Mike Barlow (UCL Department of Physics & Astronomy), a UCL research team was taking measurements of cold gas and dust regions of this famous supernova remnant in infrared light when they stumbled upon the chemical signature of argon hydrogen ions. By observing in longer wavelengths of light than can be detected by the human eye, the scientists gave credence to current theories of how argon occurs naturally.

“We were doing a survey of the dust in several bright supernova remnants using Herschel, one of which was the Crab Nebula. Discovering argon hydride ions here was unexpected because you don’t expect an atom like argon, a noble gas, to form molecules, and you wouldn’t expect to find them in the harsh environment of a supernova remnant,” said Barlow.

When it comes to a star, they are hot and ignite the visible spectrum. Cold objects like nebular dust are better seen in infrared, but there’s only one problem – Earth’s atmosphere interferes with the detection of that end of the electromagnetic spectrum. Even though we can see nebulae in visible light, what shows is the product of hot, excited gases, not the cold and dusty regions. These invisible regions are the specialty of Herschel’s SPIRE instruments. They map the dust in far-infrared with their spectroscopic observations. In this instance, the researchers were somewhat astounded when they found some very unusual data which required time to fully understand.

“Looking at infrared spectra is useful as it gives us the signatures of molecules, in particular their rotational signatures,” Barlow said. “Where you have, for instance, two atoms joined together, they rotate around their shared center of mass. The speed at which they can spin comes out at very specific, quantized, frequencies, which we can detect in the form of infrared light with our telescope.”

According to the news release, elements can exist in varying forms known as isotopes. These have different numbers of neutrons in the atomic nuclei. When it comes to properties, isotopes can be somewhat alike to each other, but they have different masses. Because of this, the rotational speed is dependent on which isotopes are present in a molecule. “The light coming from certain regions of the Crab Nebula showed extremely strong and unexplained peaks in intensity around 618 gigahertz and 1235 GHz.” By comparing data of known properties of different molecules, the science team came to the conclusion the mystery emission was the product of spinning molecular ions of argon hydride. What’s more, it could be isolated. The only argon isotope which could spin like that was argon-36! It would appear the energy released from the central neutron star in the Crab Nebula ionized the argon, which then combined with hydrogen molecules to form the molecular ion ArH+.

Professor Bruce Swinyard (UCL Department of Physics & Astronomy and Rutherford Appleton Laboratory), a member of the team, added: “Our discovery was unexpected in another way — because normally when you find a new molecule in space, its signature is weak and you have to work hard to find it. In this case it just jumped out of our spectra.”

Is this instance of argon-36 in a supernova remnant natural? You bet. Even though the discovery was the first of its kind, it is doubtless not the last time it will be detected. Now astronomers can solidify their theories of how argon forms. Current predictions allow for argon-36 and no argon-40 to also be part of supernova structure. However, here on Earth, argon-40 is a dominant isotope, one which is created through the radioactive decay of potassium in rocks.

Noble gas research will continue to be a focus of scientists at UCL. As an amazing coincidence, argon, along with other noble gases, was discovered at UCL by William Ramsay at the end of the 19th century! I wonder what he would have thought had he known just how very far those discoveries would take us?

Original Story Source: University College London (UCL) Press Release

December 5, 2013December 23, 2015 by Tammy Plotner

Subaru Telescope Reveals Orderly Massive Galaxy Evolution

FMOS spectra in the J-band (left panel) and H-band (right panel), each of which filters light so that only specific wavelengths can pass through. The horizontal axis refers to the wavelength direction while the vertical axis indicates individual spectra observed through each fiber. Small blue circles indicate the detection of emission lines (left: H? and [OIII]; right: H?, [NII]). The inset box shows the intensity of the emission lines for one galaxy. The vertical bands indicate the masked regions where bright sky (OH) emissions are prevented from entering science fibers placed on high-redshift galaxies. (Credit: FMOS-COSMOS)

Nobody likes a sloppy COSMOS (Cosmological Evolution Survey) and astronomers utilizing the Fiber-Multi-Object Spectrograph (FMOS) mounted on the Subaru Telescope have put order into chaos through their studies. The survey has found that some nine billion years ago galaxies were capable of producing new stars in a fashion as orderly as game of checkers. Despite their young cosmological age, the galaxies show signs containing high amounts of dust enriched by heavier elements – a mature state.

“These findings center on a major question: What was the universe like when it was maximally forming its stars?” says John Silverman, the principal investigator of the FMOS-COSMOS project at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU).

These “universal” questions are just what the COSMOS team seeks to answer. Their research goals are to enlighten the scales of cosmic time in relationship with the environment, formation and evolution of massive galactic structures. When studying individual galaxies, they may be able to tell if their rate of growth can be attributed to large-scale environments. Information of this type can clarify what factors the early Universe structure may have contributed to the current form of local galaxies. One of the data sets the team is focusing on is using the FMOS on the Subaru Telescope to chart out the distribution of more than a thousand galaxies which formed over nine billion years ago – a time when the Universe was hitting its star-formation peak.

“One key to generating fruitful results is collaboration between COSMOS researchers to maximize optimal use of FMOS.” Silverman continues, “In this project, researchers from Kavli IPMU in Japan and the Institute for Astronomy at the University of Hawaii (principal investigator: David Sanders) formed an effective collaboration to implement their goal.” The observations spanned 10 clear nights starting in March 2012.

Why choose spectroscopy? This advanced fiber optics technology speaks for itself, collecting light over an area of sky equal in size to that of the Moon. The FMOS focuses on the near-infrared, filtering out unwanted emissions caused by warm temperatures and can acquire spectra from 400 galaxies simultaneously with a wide field of coverage of 30 arc minutes at prime-focus. By employing such a wide field of view, astronomers can squeeze in a wide range of objects in their local environments. This enables researchers to maximize information on star-forming regions, cluster formation, and cosmology.

As David Sanders, the principal investigator of the FMOS-COSMOS project at IfA, puts it, “FMOS has clearly revolutionized our ability to study how galaxies form and evolve across cosmic time. It is currently the most powerful instrument we have to study the large numbers of objects needed to understand galaxies of all sizes, shapes and masses — from the largest ellipticals to the smallest dwarfs. We are extremely fortunate that the Kavli IPMU-IfA collaboration is giving us this unique opportunity to study the distant universe in such exquisite detail.”

FMOS will soon be famous by revealing its true potential. It has been collecting copious amounts of data in a high spectral resolution mode and at a very successful rate. So far it has accomplished nearly half of its goal – to examine over a thousand galaxies with redshifts to map the large-scale structure. The current survey consists of mapping an area of sky which spans a square degree in high-resolution mode and future plans for FMOS will involve enlarging the area. This expanded coverage will complement other instruments on alternative telescopes which have a wider spectral imaging system or a higher resolution which is limited to a smaller area. These combined findings may one day result in showing us some of the very first structures that eventually evolved into the massive galaxy clusters we see today!

Original Story Source: Kavli Institute for the Physics and Mathematics of the Universe News Release.

November 20, 2013December 23, 2015 by Tammy Plotner

Exploring Our Galaxy’s Ancient Brown Dwarfs

A brown dwarf from the thick-disk or halo is shown. Although astronomers observe these objects as they pass near to the solar system, they spend much of their time away from the busiest part of the Galaxy, and the Milky Way's disk can be seen in the background. Credit: John Pinfield

As the name implies, a brown dwarf is small… only about 7% the size of the Sun. As far as stellar senior citizens go, they’re cool. Zipping along through space at speeds of 100 to 200 kilometers per second, they may have formed back when our galaxy was young – perhaps 10 billion years ago. Now a team of astronomers headed by Dr. David Pinfield at the University of Hertfordshire has identified a pair of the oldest brown dwarfs known… a set of orbs which could be the harbinger of a huge amount of new, unseen objects.

Although we sometimes refer to them as stars, brown dwarfs are in a class of their own. Because they didn’t ignite in nuclear fusion, they don’t generate internal heat like an ordinary star. After they are formed, they continue to cool and fade as time passes. This process makes them very difficult to observe and the discovery of two very old brown dwarfs, with temperatures of 250-600 C is cause for astronomical excitement.

Just how did Pinfield’s team pick such tiny objects out of the vastness of space? The discovery was facilitated thanks to a survey made by the Wide-field Infrared Survey Explorer (WISE), a NASA observatory that scanned the mid-infrared sky from orbit in 2010 and 2011. The ancient objects are cataloged as WISE 0013+0634 and WISE 0833+0052, and they are located in the constellations of Pisces and Hydra. Because they are so elusive, they were also confirmed by large ground-based telescopes (Magellan, Gemini, VISTA and UKIRT).

However, identifying the pair wasn’t easy. Seeing through the eyes of infrared reveals a crowded space – one populated with reddened stars, distant background galaxies and pockets of nebulous gas and dust. Picking out such a small character from a stellar cast would be like finding one tiny pearl in the vastness of an ocean. But Pinfield’s researchers employed a new method which utilizes WISE’s capabilities. As it scanned the sky over and over again, it revealed the cool, brown dwarfs – picking up the faint signature that other searches had missed.

These two particular brown dwarfs are different from the other slow movers of their type. By studying their spectra, the astronomers have identified atmospheres almost entirely comprised of hydrogen. This sets them apart from younger stars which have an abundance of heavier elements. Does being lighter make them speedier? According to Pinfield, “Unlike in other walks of life, the galaxy’s oldest members move much faster than its younger population.”

Stars near to Sun are considered the “local volume” and are created with three overlapping populations – the thin disk, the thick disk and the halo. Each of these layers has a certain amount of age associated with it: the oldest being the thickest and its member stars move up and down at a higher rate of speed. The halo contains both disks, along with the initial materials which formed the very first stars. Thin disk objects abound in the local volume and account for about 97% of the local stars, while thick disk and halo objects are a meager 3%. Chances are, brown dwarfs belong to that smaller percentage which explains why these fast-moving thick-disk/halo objects are only now being revealed.

Just how many may await discovery? Scientists surmise there may be as many as 70 billion brown dwarfs in the galaxy’s thin disk, and the thick disk and halo take up significantly larger galactic volumes. Even at a tiny 3%, this means there could be an army of ancient brown dwarfs in the galaxy. “These two brown dwarfs may be the tip of an iceberg and are an intriguing piece of astronomical archaeology,” said Pinfield. “We have only been able to find these objects by searching for the faintest and coolest things possible with WISE. And by finding more of them we will gain insight into the earliest epoch of the history of the galaxy.”

Original Story Source: Royal Astronomical Society News Release. For further study: “A deep WISE search for very late type objects and the discovery of two halo/thick-disk T dwarfs: WISE 0013+0634 and WISE 0833+0052”, D. J. Pinfield et al, Monthly Notices of the Royal Astronomical Society, in press.

October 23, 2013December 23, 2015 by Matthew Francis

Taking Measure: A ‘New’ Most Distant Galaxy

Galaxy z8_GND_5296 (seen in the inset) is the earliest galaxy that astronomers have measured the distance to accurately. It formed approximately 700 million years after the Big Bang, and is forming stars at an incredibly rapid rate. [Credit: V. Tilvi (Texas A&M), S. Finkelstein (UT Austin), the CANDELS team, and HST/NASA]

“The farthest galaxy yet seen!” Haven’t we heard that one before? (See here and here, for example.) While it’s true that astronomers keep pushing farther back in time with better instruments, there are fundamental challenges both in observing and measuring the distances to the earliest galaxies in the cosmos.

That’s why this new observation of a galaxy that formed about 700 million years after the Big Bang is significant. While scores of galaxies have been identified that formed in that era, astronomers have only measured accurate distances for five of them. This galaxy marks the sixth, and it is the farthest of the bunch. Perhaps even more important than the distance measurement, researchers determined that this galaxy gave birth to new stars at more than 100 times the rate the Milky Way does today. That indicates early galaxies may have been more aggressive with star-formation than previously believed. Continue reading “Taking Measure: A ‘New’ Most Distant Galaxy”

September 25, 2013December 23, 2015 by Tammy Plotner

New Camera Aboard APEX Gets First Light

This image of the star formation region NGC 6334 is one of the first scientific images from the ArTeMiS instrument on APEX. The picture shows the glow detected at a wavelength of 0.35 millimetres coming from dense clouds of interstellar dust grains. The new observations from ArTeMiS show up in orange and have been superimposed on a view of the same region taken in near-infrared light by ESO’s VISTA telescope at Paranal. Credit: ArTeMiS team/Ph. André, M. Hennemann, V. Revéret et al./ESO/J. Emerson/VISTA Acknowledgment: Cambridge Astronomical Survey Unit

And the “Cat’s Paw” was waiting to strike! In this exceptionally detailed image of star-forming region NGC 6334 we can get a sense of just how important new instrumentation can be. In this case it’s a new camera called ArTeMiS and it has just been installed on a 12-meter diameter telescope located high in the Atacama Desert. The Atacama Pathfinder Experiment – or APEX for short – operates at millimeter and submillimeter wavelengths, providing us with observations ranging between radio wavelengths and infrared light. These images give astronomers powerful new data to help them further understand the construction of the Universe.

Exactly what is ArTeMiS? The camera provides wide field views at submillimeter wavelengths. When added to APEX’s arsenal, it will substantially increase the amount of details a particular object has to offer. It has a detector array similar to a CCD camera – a new technology which will enable it to create wide-field maps of target areas with a greater amount of speed and a larger amount of pixels.

Like almost all new telescope projects, both personal and professional, the APEX team met up with “first light” problems. Although the ArTeMiS Camera was ready to go, the weather simply wouldn’t cooperate. According to the news release, very heavy snow on the Chajnantor Plateau had almost buried the building in which the scope operations are housed! However, the team was determined. Using a makeshift road and dodging snow drifts, the team and the staff at the ALMA Operations Support Facility and APEX somehow managed to get the camera to its location safely. Undaunted, they installed the ArTeMiS camera, worked the cryostat into position and locked the instrumentation down in its final position.

However, digging their way out of the snow wasn’t all the team had to contend with. To get ArTeMis on-line, they then had to wait for very dry weather since submillimeter wavelengths of light are highly absorbed by atmospheric moisture. Do good things come to those who wait? You bet. When the “magic moment” arrived, the APEX team was ready and the initial test observations were a resounding success. ArTeMiS quickly became the focus tool for a variety of scientific projects and commissioned observations. One of these projects was to image star-forming region NGC 6334 – the Cat’s Paw Nebula – in the southern constellation of Scorpius. Thanks to the new technology, the ArTeMiS image shows a superior amount of detail over earlier photographic observations taken with APEX.

What’s next for ArTeMiS? Now that the camera has been tested, it will be returned to Saclay in France to have even more detectors installed. According to the researchers: ” The whole team is already very excited by the results from these initial observations, which are a wonderful reward for many years of hard work and could not have been achieved without the help and support of the APEX staff.”

Original Story Source: ESO Public News Release.