To Boldly Go Where No Glass Has Gone Before

Queensland University of Technology‘s (QUT) first foray into space is bound to be a giant step for mankind.

Dr. Martin Castillo from QUT Science and Engineering Faculty, and researcher for the university’s micro-gravity drop tower, has partnered with the United States Air Force to fund world-first research into the development of ZBLAN glass.

Dr. Castillo said the special glass will be the first QUT project to be launched into space. Read More →

From Big Bang to Big Data

ASTRON, the Netherlands Institute for Radio Astronomy and IBM (NYSE: IBM) today announced an initial 32.9 million EURO, five-year collaboration to research extremely fast, but low-power exascale computer systems targeted for the international Square Kilometre Array (SKA). The SKA is an international project to build the world’s largest and most sensitive radio telescope. Scientists estimate that the processing power required to operate the telescope will be equal to several millions of today’s fastest computers.

ASTRON is one of the leading scientific partners in the international project that is developing the SKA. Upon completion in 2024, the telescope will be used to explore evolving galaxies, dark matter and even the very origins of the universe—dating back more than 13 billion years. Read More →

Clocking an Accelerating Universe

BOSS measures the three-dimensional clustering of galaxies at various redshifts, revealing their precise distance, the age of the universe at that redshift, and how fast the universe has expanded. The measurement uses a "standard ruler" based on the regular variations of the temperature of the cosmic microwave background (

Some six billion light years ago, almost halfway from now back to the big bang, the universe was undergoing an elemental change. Held back until then by the mutual gravitational attraction of all the matter it contained, the universe had been expanding ever more slowly. Then, as matter spread out and its density decreased, dark energy took over and expansion began to accelerate.

Today BOSS, the Baryon Oscillation Spectroscopic Survey, the largest component of the third Sloan Digital Sky Survey (SDSS-III), announced the most accurate measurement yet of the distance scale of the universe during the era when dark energy turned on.

“We’ve made precision measurements of the large-scale structure of the universe five to seven billion years ago – the best measure yet of the size of anything outside the Milky Way,” says David Schlegel of the Physics Division at the U.S. Department of Energy‘s Lawrence Berkeley National Laboratory (Berkeley Lab), BOSS’s principal investigator. “We’re pushing out to the distances when dark energy turned on, where we can start to do experiments to find out what’s causing accelerating expansion.”

How to measure expansion in an accelerating universe

Accelerating expansion was announced less than 14 years ago by both the Supernova Cosmology Project (SCP) based at Berkeley Lab and the competing High-z Supernova Search Team, a discovery that resulted in 2011 Nobel Prizes for the SCP’s Saul Perlmutter and High-z Team members Brian Schmidt and Adam Riess. Acceleration may result from an unknown something dubbed “dark energy” – or, dark energy may be just a way of saying we don’t understand how gravity really works.

The first step in finding out is to establish a detailed history of expansion. Unlike supernova searches, which depend on the brightness of exploding stars, BOSS uses a technique called baryon acoustic oscillation (BAO) to determine the distances to faraway galaxies.

Baryon acoustic oscillation measures the angle across the sky of structures of known size, the peaks where galaxies cluster most densely in the network of filaments and voids that fill the universe. Since these density peaks recur regularly, the angle between appropriate pairs of galaxies as precisely measured from Earth reveals their distance – the narrower the apparent angle, the farther away they are.

Knowing the distance to an object tells its age as well, since its light travels from there to here at known speed. And the redshift of the light reveals how the universe has expanded since that time, as expansion stretches space itself; the wavelength of light traveling through space toward Earth stretches proportionally, becoming redder and revealing the expansion of the universe since the light left its source.

“BOSS’s first major cosmological results establish the accurate three-dimensional positions of 327,349 massive galaxies across 3,275 square degrees of the sky, reaching as far back as redshift 0.7 – the largest sample of the universe ever surveyed at this high density,” says Martin White of Berkeley Lab’s Physics Division, a professor of physics and astronomy at the University of California at Berkeley and chair of the BOSS science survey teams. “BOSS’s average redshift is 0.57, equivalent to some six billion light-years away. BOSS gives that distance to within 1.7 percent – 2,094 megaparsecs plus or minus 34 megaparsecs – the most precise distance constraint ever obtained from a galaxy survey.”

The origin of BAO, the regular clustering of ordinary matter (called “baryons” by astronomical convention), was the pressure of sound waves (“acoustic”) moving through the universe when it was still so hot that light and matter were mixed together in a kind of soup, in which the sound waves created areas of regularly varying density (“oscillation”). By 380,000 years after the big bang, expansion had cooled the soup enough for ordinary matter to condense into hydrogen atoms (invisible dark matter was also part of the soup) and for light to go its separate way.

At that moment variations in density were preserved as variations in the temperature of the cosmic microwave background (CMB), a phenomenon first measured by Berkeley Lab astrophysicist George Smoot, for which he shared the 2006 Nobel Prize. The warmer regions of the CMB signal areas where the density of matter was greater; these regions seeded the galaxies and clusters of galaxies that form the large-scale structure of the universe today. Thus the cosmic microwave background establishes the basic scale of baryon acoustic oscillation used to measure the expansion history of the universe.

BOSS’s data on galaxy clustering and redshifts can be applied not only to BAO but also to a separate technique called “redshift space distortions” – a direct test of gravity that measures how fast neighboring galaxies are moving together to form galaxy clusters.

What if dark energy isn’t an unknown force or substance, but instead a shortcoming of Albert Einstein’s General Theory of Relativity, our best-yet theory of gravity? General Relativity predicts how fast galaxies should be moving toward one another in galaxy clusters, and, in the aggregate, how fast the structure of the universe should be growing. Any departure from its predictions would mean the theory is flawed.

“We depend on redshift to know expansion rates and how structure was growing at different times in the past,” says Beth Reid, a Hubble Fellow at Lawrence Berkeley National Laboratory who directed the BOSS study of redshift space distortions. “But redshifts aren’t uniform. Galaxies are carried along in the Hubble flow as the universe expands, but they also have their own velocities. They tend to fall toward denser regions, for example. Because the ones on the far side of a dense region are coming toward us, their redshift makes them look closer than they really are; the opposite is true for the galaxies on the near side, which are falling away from us – they look farther away.”

Statistical analysis of the redshifts of the hundreds of thousands of galaxies in the BOSS dataset can take into account the peculiarities of local variation and still produce a dependable measure of distance, the Hubble expansion rate, and the growth rate of structure in the universe. With these techniques, Reid and her colleagues have measured gravity on a scale of 100 million light years, far larger than the most accurate gravity measure yet, which is based on the distance from Earth to the moon.

The right tools to do the job

BOSS obtained these best-yet measures with the wide-field Sloan Telescope at the Apache Point Observatory in New Mexico, designed especially for galaxy surveys but mounting a spectrograph far more sophisticated than was available to earlier SDSS surveys.

“The 2.5-meter Sloan Telescope remains the world’s premier facility for wide-field spectroscopy because it uses fiber-fed spectrographs, which offer a huge numerical advantage,” says Natalie Roe, director of Berkeley Lab’s Physics Division and instrument scientist for BOSS, who directed construction of the new spectrographs.

For each 15-minute exposure, covering three degrees of the sky, a thousand optical fibers are inserted by hand into aluminum “plug plates” and positioned at the telescope’s focal plane; each fiber is targeted on a specific distant bright galaxy, selected from earlier SDSS imaging. The BOSS instrument uses 50 percent more fibers than earlier SDSS runs, each with finer diameter; for more coverage and finer resolution the new spectrograph incorporates two red cameras using the thick, red-sensitive astronomical CCDs invented and fabricated at Berkeley Lab, as well as two new blue cameras.

“All the data collected by BOSS flows through a data-processing pipeline at Berkeley Lab,” says Stephen Bailey of the Physics Division, who describes himself as the “baby sitter of the pipeline.” Working with Schlegel at Berkeley Lab and Adam Bolton at the University of Utah, Bailey “turns the data into something we can use – catalogues of the hundreds of thousands galaxies, eventually well over a million, each identified by their two-dimensional positions in the sky and their redshifts.” The data are processed and stored on the Riemann computer cluster, operated by Berkeley Lab’s High-Performance Computing Services group.

The current crop of BOSS papers is based on less than a quarter of the data BOSS will continue to collect until the survey ends in 2014. So far, all lines of inquiry point toward the so-called “concordance model” of the universe: a “flat” (Euclidean) universe that bloomed from the big bang 13.7 billion years ago, a quarter of which is cold dark matter – plus a few percent visible, ordinary, baryonic matter (the stuff we’re made of). All the rest is thought to be dark energy in the form of Einstein’s cosmological constant: a small but irreducible energy of puzzling origin that’s continually stretching space itself.

But it’s way too soon to think that’s the end of the story, says Schlegel. “Based on the limited observations of dark energy we’ve made so far, the cosmological constant may be the simplest explanation, but in truth, the cosmological constant has not been tested at all. It’s consistent with the data, but we really have only a little bit of data. We’re just beginning to explore the times when dark energy turned on. If there are surprises lurking there, we expect to find them.”

Source: Lawrence Berkley National Laboratory


Lauren Anderson, Eric Aubourg, Stephen Bailey, & et al. (2012). The clustering of galaxies in the SDSS-III Baryon Oscillation
Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 9
Spectroscopic Galaxy Sample Monthly Notices of the Royal Astronomical Society arXiv: 1203.6594v1

Beth A. Reid, Lado Samushia, Martin White, & et al. (2012). The clustering of galaxies in the SDSS-III Baryon Oscillation
Spectroscopic Survey: measurements of the growth of structure and expansion
rate at z=0.57 from anisotropic clustering Monthly Notices of the Royal Astronomical Society arXiv: 1203.6641v1

[Awesome Alert] Deflecting Asteroids with Lasers

Who remembers the game Asteroids? What if that were reality?

Pioneering engineers at the University of Strathclyde in Glasgow are developing an innovative technique based on lasers that could radically change asteroid deflection technology. This sounds like something straight out of a sci-fi film but the research has merit (and is just really cool!).

The research has unearthed the possibility of using a swarm of relatively small satellites flying in formation and cooperatively firing solar-powered lasers onto an asteroid – this would overcome the difficulties associated with current methods that are focused on large unwieldy spacecraft.

Dr. Massimiliano Vasile, of Strathclyde’s Department of Mechanical and Aerospace Engineering, is leading the research. He said: “The approach we are developing would involve sending small satellites, capable of flying in formation with the asteroid and firing their lasers targeting the asteroid at close range.

“The use of high power lasers in space for civil and commercial applications is in its infancy and one of the main challenges is to have high power, high-efficiency and high beam quality all at the same time.

“The additional problem with asteroid deflection is that when the laser begins to break down the surface of the object, the plume of gas and debris impinges the spacecraft and contaminates the laser. However, our laboratory tests have proven that the level of contamination is less than expected and the laser could continue to function for longer than anticipated.”

Just over 100 years ago a 2000-kilometer area of vegetation was destroyed when an object believed to be 30-50 meters in diameter exploded in the skies above Tunguska, Siberia. While the likelihood of an immediate threat from a similar asteroid strike remains low, it is widely recognized that researching preventative measures is of significant importance.

Dr. Vasile added: “The Tunguska class of events are expected to occur within a period of a few centuries. Smaller asteroids collide with Earth more frequently and generally burn in the atmosphere although some of them reach the ground or explode at low altitude potentially causing damage to buildings and people.

“We could reduce the threat posed by the potential collision with small to medium size objects using a flotilla of small agile spacecraft each equipped with a highly efficient laser which is much more feasible than a single large spacecraft carrying a multi mega watt. Our system is scalable, a larger asteroid would require adding one or more spacecraft to the flotilla, and intrinsically redundant – if one spacecraft fails the others can continue.”

Dr. Vasile is now investigating the use of the same concept to remove space debris. The number of objects in orbit classified as debris is ever-increasing and with no widely accepted solution for their removal. Researchers at the University of Strathclyde believe the space-borne lasers could be used to lower the original orbit of the space debris and reduce the congestion.

Dr. Vasile said: “The amount of debris in orbit is such that we might experience a so called Kessler syndrome – this is when the density becomes so high that collisions between objects could cause an exponentially increasing cascade of other collisions.

“While there is significant monitoring in place to keep track of these objects, there is no specific system in place to remove them and our research could be a possible solution.

“A major advantage of using our technique is that the laser does not have to be fired from the ground. Obviously there are severe restrictions with that process as it has to travel through the atmosphere, has a constrained range of action and can hit the debris only for short arcs.”

The research was carried out in collaboration with the University of Strathclyde’s Institute of Photonics and was presented to the Planetary Society at the end of February.

What are your thoughts on this research? Do you believe it can be developed to the scale required to deflect a real asteroid?

Source: University of Strathclyde

NASA Measures Impact of Solar Flare on Earth’s Atmosphere

A key NASA instrument that can directly measure the impact of solar events on the Earth’s upper atmosphere has weighed in on the huge flare that impacted Earth last week.

The flare was considered one of the largest solar events in years even though its impact on the power grid and communications was minimal due to the angle it hit Earth.

Its direct interaction with the upper atmosphere was measured by NASA’s SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument orbiting on the TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics) satellite.

The upper atmosphere heated up, and huge spikes occurred in infrared emission from nitric oxide and carbon dioxide, said Marty Mlynczak, SABER’s associate-principal investigator at NASA’s Langley Research Center in Hampton, Va.

Sol ‘waking up’

“It’s been seven years since we’ve had a storm like that,” he said. “This is the first major storm event since the deep solar minimum of 2008-2009. We are finally seeing the Sun ‘wake up’ as it proceeds to the next solar maximum.”

A solar maximum is a period of increased activity on the Sun, and minimum-to-maximum-to-minimum cycles generally last 11 years each. Solar activity began to pick up in 2010, is steadily increasing and should peak in late 2014.

As the Sun becomes more active, Mlynczak said, it emits more ultraviolet radiation and produces more solar flares – coronal mass ejections (CMEs) – which are absorbed in the atmosphere. “More heating results, and the atmosphere gets warmer, and the infrared emission increases,” he said.

“We don’t know yet how these affect weather or climate — likely there is not any direct effect,” he said, “but there may be, over time, influences on ozone that affect climate.”

“These results are very timely,” said James Russell, SABER’s principal investigator at Hampton University in Hampton, Va. “SABER is cataloging the atmospheric response to solar forcing and is providing a solid baseline for examining long-term changes in the climatology of the upper atmosphere.”

“The data set is a vital resource for study of atmospheric trends, for validating atmospheric models of the region, and for evaluating our understanding of solar/atmosphere coupling, he said.

Unique Record

SABER is one of four instruments on the TIMED spacecraft launched in December 2001. TIMED studies the Earth’s mesosphere and lower thermosphere, the least explored and least understood region of our atmosphere.

“SABER has a unique, continuous record of over 3,700 days observation of the climate and energy balance of the Earth’s upper and outer atmosphere,” Mlynczak said.

“From this, we are learning with each event how sensitive this region of the Earth’s atmosphere is to short- and long-term variability of the Sun,” he said. “We have documented the decline of the prior solar cycle, the deep minimum and the ‘ground state’ of the atmosphere during that time, and are now seeing the uptick.”

TIMED was designed to operate for two years but has operated flawlessly for more than 10 years. Another NASA review is planned in 2013 to determine if SABER will continue operating for at least three more years.

“This is well before the predicted solar maximum,” Mlynczak said. There are no other measurements like it, and the entire SABER science team is working hard to make the scientific case to keep the mission operating.”

Partners in the SABER mission include Hampton University in Hampton, Va.; Science Systems and Applications, Inc.; GATS Inc.; NASA’s Goddard Spaceflight Center in Greenbelt, Md.; and Johns Hopkins University Applied Physics Laboratory in Laurel, Md. Utah State University Space Dynamics Laboratory built SABER.

Michael Finneran
NASA Langley Research Center

For more information about Langley go to http :// www . nasa . gov / langley

Source: NASA

Image Credit: Credit: NASA/JHU/APL

Researchers Set New Record in Magnetic Field Production

Researchers at Los Alamos National Laboratory‘s biggest magnet facility today met the grand challenge of producing magnetic fields in excess of 100 tesla while conducting six different experiments. The hundred-tesla level is roughly equivalent to 2 million times Earth’s magnetic field. Read More →

Astronomers discover rare ’emerald-cut’ galaxy

An international team of astronomers has discovered a rare square galaxy with a striking resemblance to an emerald cut diamond.

The astronomers – from Australia, Germany, Switzerland and Finland – discovered the rectangular shaped galaxy within a group of 250 galaxies some 70 million light years away.

“In the Universe around us, most galaxies exist in one of three forms: spheroidal, disc-like, or lumpy and irregular in appearance,” said Associate Professor Alister Graham from Swinburne University of Technology.

He said the rare rectangular-shaped galaxy was a very unusual object. “It’s one of those things that just makes you smile because it shouldn’t exist, or rather you don’t expect it to exist.

“It’s a little like the precarious Leaning Tower of Pisa or the discovery of some exotic new species which at first glance appears to defy the laws of nature.”
The unusually shaped galaxy was detected in a wide field-of-view image taken with the Japanese Subaru Telescope for an unrelated program by Swinburne astrophysicist Dr Lee Spitler.

The astronomers suspect it is unlikely that this galaxy is shaped like a cube. Instead, they believe that it may resemble an inflated disc seen side on, like a short cylinder.

Support for this scenario comes from observations with the giant Keck Telescope in Hawaii, which revealed a rapidly spinning, thin disc with a side on orientation lurking at the centre of the galaxy. The outermost measured edge of this galactic disc is rotating at a speed in excess of 100,000 kilometres per hour.

“One possibility is that the galaxy may have formed out of the collision of two spiral galaxies,” said Swinburne’s Professor Duncan Forbes, co author of the research.

“While the pre-existing stars from the initial galaxies were strewn to large orbits creating the emerald cut shape, the gas sank to the mid plane where it condensed to form new stars and the disc that we have observed.”

Despite its apparent uniqueness, partly due to its chance orientation, the astronomers have managed to glean useful information for modelling other galaxies.

While the outer boxy shape is somewhat reminiscent of galaxy merger simulations which don’t involve the production of new stars, the disc-like structure is comparable with merger simulations involving star formation.

“This highlights the importance of combining lessons learned from both types of past simulation for better understanding galaxy evolution in the future,” said Associate Professor Graham.

“One of the reasons this emerald cut galaxy was hard to find is due to its dwarf-like status: it has 50 times less stars than our own Milky Way galaxy, plus its distance from us is equivalent to that spanned by 700 Milky Way galaxies placed end-to-end.

“Curiously, if the orientation was just right, when our own disc-shaped galaxy collides with the disc-shaped Andromeda galaxy about three billion years from now we may find ourselves the inhabitants of a square looking galaxy.”

Source: Swinburne University of Technology


Alister W. Graham, Lee R. Spitler, & Duncan A. Forbes (2012). LEDA 074886: A REMARKABLE RECTANGULAR-LOOKING GALAXY The Astrophysical Journal arXiv:1203.3608v1

NuSTAR Mission Update and Overview

Image credit: NASA

On Friday NASA announced that the launch of its newest spacecraft from California will unfortunately be delayed a bit longer. Regardless, I thought I’d post about the mission as this is a project I’m eagerly awaiting. The mission, known as NuSTAR, will map areas of the Milky Way Galaxy. This particular project is one of the least expensive NASA has ever deployed. NASA has announced that launch will hopefully occur within the next two months.

NuStar Mission Overview

One mission objective is to count collapsed stars and black holes near the center of the Milky Way. Scientists also hope to get a closer look at young supernova to understand the formation process as well as  how the different elements of supernovas are created. Furthermore, the mission team hopes to develop a deeper understanding of what powers the jets of particles streaming from the largest black holes. Scientists also hope the mission will encounter a few gamma ray bursts leading to a deeper understanding of them as well.

This will be the first time the new NuSTAR telescope will be used. The folding telescope is at least 10 times stronger than previous telescopes employed on the Chandra and XMM projects. The telescope will be folded until the rocket reaches low earth orbit where it will proceed to unfold. Mission specialists say that the time the telescope takes to unfold will be the scariest aspect of the launch. This will be one of the first times that a folding telescope has been deployed in an unmanned spacecraft.

NuSTAR is a Small Explorer mission led by the California Institute of Technology and managed by NASA’s Jet Propulsion Laboratory, both in Pasadena, Calif., for NASA’s Science Mission Directorate. The spacecraft was built by Orbital Sciences Corporation, Dulles, Va. Its instrument was built by a consortium including Caltech; JPL; the University of California, Berkeley; Columbia University, New York; NASA’s Goddard Space Flight Center in Greenbelt, Md.; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory, Calif.; and ATK Aerospace Systems, Goleta, Calif. NuSTAR will be operated by UC Berkeley, with the Italian Space Agency providing its equatorial ground station located at Malindi, Kenya. The mission’s outreach program is based at Sonoma State University, Calif. NASA’s Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

The mission is expected to last two years and results will be published as they become available from this exciting project.

Right now I just hope NASA get things worked out and gets this up in the sky sooner rather than later.

Astrobiologists Discover Life Components in Meteorites…Maybe

New NASA research suggests that creating the building blocks of life might not necessary be as hard as previously assumed. This research means that certain components of those building blocks could have been delivered to Earth in the form of comets and meteorites. The research also advocates the idea that these building blocks could be produced in different manners. This means that certain compounds can be made in either cold or hot environments.

While similar research has been published in years past with inconclusive results, time will tell if this team has gotten it right this time around. I have no doubt these findings will be heavily scrutinized (especially in terms of contamination) as with previous studies – the early Murchison meteorite research comes immediately to mind. For the time being, I’m hopeful but not yet convinced. Either way, this study has merit and is worthy of further examination.

Meteorites contain a large variety of nucleobases, an essential building block of DNA. Artist concept credit: NASA

The Findings:

The NASA Goddard Space Flight’s Astrobiology Analytical Laboratory analyzed a number of meteorite samples that had experienced high temperatures. These particular objects had compounds that were similar to amino acids. These acids are used to make proteins. Previously, it was understood that these compounds could only form at relatively low temperatures. Interestingly enough, the new class of reaction is similar to the type of chemical reaction that was used to process coal into gasoline to overcome fuel shortages during the Second World War.

The original experiments that showed a connection between Fischer Tropsch type reactions and amino acids were preformed a long time ago. Meteorites contain several types of nucleobases and the team eventually wants to search for amino acids in all of the known carbon-rich meteorite groups. They have actually expressed feelings that suggest it would be strange if they didn’t find any further amino acids.

“Although we’ve found amino acids in carbon-rich meteorites before, we weren’t expecting to find them in these specific groups, since the high temperatures they experienced tend to destroy amino acids,” said Dr. Aaron Burton, a researcher in NASA’s Postdoctoral Program stationed at NASA Goddard. “However, the kind of amino acids we discovered in these meteorites indicates that they were produced by a different, high-temperature process as their parent asteroids gradually cooled down.” Burton is lead author of a paper on this discovery that appeared March 9 in Meteoritics and Planetary Science (reference below).

The team believes the majority of the amino acids they found in the 14 meteorites were truly created in space, and not the result of contamination from terrestrial life, for a few reasons. First, the amino acids in life (and in contamination from industrial products) are frequently linked together in long chains, either as proteins in biology or polymers in industrial products. Most of the amino the amino acids discovered in the new research were not bound up in proteins or polymers. In addition, the most abundant amino acids found in biology are those that are found in proteins, but such “proteinogenic” amino acids represent only a small percentage of the amino acids found in the meteorites. Finally, the team analyzed a sample of ice taken from underneath one of the meteorites. This ice had only trace levels of amino acids suggesting the meteorites are relatively pristine.

The experiments showing FTT reactions produce amino acids were performed over 40 years ago. The products have not been analyzed with modern techniques, so the exact distributions of amino acid products have not been determined. The team wants to test FTT reactions in the laboratory using a variety of ingredients and conditions to see if any produce the types of amino acids with the abundances they found in the 14 meteorites.

What are your thoughts? Is it possible that life came about as a result of a meteorite bringing “alien compounds” to Earth?


BURTON, A., ELSILA, J., CALLAHAN, M., MARTIN, M., GLAVIN, D., JOHNSON, N., & DWORKIN, J. (2012). A propensity for n-ω-amino acids in thermally altered Antarctic meteorites Meteoritics & Planetary Science DOI: 10.1111/j.1945-5100.2012.01341.x

NASA – National Aeronautics and Space Administration. (2012, March 9). NASA. Retrieved March 15, 2012, from

Future MeerKAT Installation Completes Spectral Analysis of NGC 3109

The KAT-7 radio telescope is probably the largest found in the southern hemisphere. Eventually, it will be expanded to include technology that makes up an even larger system called the MeerKAT. It should remain the largest unit down south until the Square Kilometer Array is finished around 2024. Though one could argue that KAT-7 is still under construction, it is already yielding some pretty amazing results. The device has observed radio emissions from neutral hydrogen gas in the NGC 3109 galaxy.

NGC 3109

NGC 3109 is classified as a Magellanic type irregular galaxy, but it may in fact be a small spiral galaxy. If it is a spiral galaxy, it would be the smallest in the Local Group (dwarf galaxy). NGC 3109 has a mass of about 2.3×109 times the mass of the Sun, of which 20% is in the form of neutral hydrogen. It is oriented edge-on from our point of view, and may contain a disk and a halo. The disk appears to be composed of stars of all ages, whereas the halo contains only very old and metal-poor stars. NGC 3109 does not appear to possess a galactic nucleus.It is about 4.3 million light-years from Earth and is located in the constellation of Hydra. In areas where the gas is moving in a relative direction towards the point of observation, the spectral lines are Doppler shifted upward. In areas where the opposite is true, the spectral lines are downshifted. This means that astronomers can ultimately map the direction in which the gas in the galaxy is moving.

Mapping the universe with neutral hydrogen substances is one of the primary missions for the SKA and MeerKAT installations. The universe is constantly expanding, and this means that distant galaxies are moving away from one another. Spectral analysis should help to calculate just how far away these galaxies are.

NGC 3109

Image Credit: NGC 3109 by GALEX


G. Pietrzynski, W. Gieren, A. Udalski, I. Soszynski, F. Bresolin, R. P. Kudritzki, R. Mennickent, & M. Szymanski (2006). The Araucaria Project. A Wide-Field Photometric Survey for Cepheid
Variables in NGC 3109 Astrophys.J.648:366-374,2006 arXiv: astro-ph/0605226v1

Lee, M. (1993). The distance to nearby galaxy NGC 3109 based on the tip of the red giant branch The Astrophysical Journal, 408 DOI: 10.1086/172598

Musella, I., Piotto, G., & Capaccioli, M. (1997). On the cepheid variables of nearby galaxies. III. NGC 3109. The Astronomical Journal, 114 DOI: 10.1086/118528

Barnes, D., & de Blok, W. (2001). On the Neutral Gas Content and Environment of NGC 3109 and the Antlia Dwarf Galaxy The Astronomical Journal, 122 (2), 825-829 DOI: 10.1086/321170

KAT-7. (n.d.). Square Kilometre Array (SKA) Africa. Retrieved March 16, 2012, from