Tag Archives: Spitzer space telescope

A 12-year study of massive stars has reaffirmed that our Galaxy has four spiral arms, following years of debate sparked by images taken by NASA’s Spitzer Space Telescope that only showed two arms. (c) University of Leeds

The Milky Way grows back two spiral arms

There has been a debate over the number of spiral arms the Milky Way galaxies has, due to mixed results in the past. For years, it was believed the Milky Way had four spiral arms, but in 2008 readings from the Spitzer Space Telescope suggested it actually had only two. Wouldn’t you know it, a new study that looked at young and massive star found that the Milky Way must have four arms.

Four arms, not two, survey suggests

From our perspective, it’s impossible to simply pan out and have a view of how the Milky Way looks like. Most certainly you’ve seen quite a couple of beautiful renditions of the Milky Way – most of which with two spiral arms – however these are all artist impressions. Simple computer generated graphics based on scientists’ description. Raw data is everything we have at the moment to interpret the size, shape and structure of our very own galaxy.

A 12-year study of massive stars has reaffirmed that our Galaxy has four spiral arms, following years of debate sparked by images taken by NASA’s Spitzer Space Telescope that only showed two arms. (c) University of Leeds

A 12-year study of massive stars has reaffirmed that our Galaxy has four spiral arms, following years of debate sparked by images taken by NASA’s Spitzer Space Telescope that only showed two arms. (c) University of Leeds

James Urquhart at the Max Planck Institute for Radio Astronomy in Bonn, Germany and team recently performed a survey of massive stars from the Milky Way. Since massive stars fly high and die fast  – they only last for some 10 million years or so – meaning that they are only found in the arms in which they formed, which could explain the discrepancy in the number of galactic arms that different research teams have claimed. The controversial 2008 Spitzer survey analyzed some 110 million stars, most of which were cooler, lower-mass stars – stars like our sun. These are much more numerous than the massive and bright stars targeted by the present study.

 “It’s exciting that we are able to use the distribution of young massive stars to probe the structure of the Milky Way and match the most intense region of star formation with a model with four spiral arms,” said Urquhart.

Several radio telescopes in Australia, the U.S. and China were used to observe about 1,650 massive stars over the course of 12 years. Scientists calculated the distances and luminosities between them and came up with a spatial distribution that suggests a four spiral arm galaxy.

“Star formation researchers, like me, grew up with the idea that our galaxy has four spiral arms. It’s great that we have been able to reaffirm that picture,” said astronomer Melvin Hoare at the University of Leeds, a co-author of the research paper.

Findings were reported in a paper published in the Monthly Notices of the Royal Astronomical Society.

These are NASA Hubble Space Telescope natural-color images of four target galaxy clusters that are part of an ambitious new observing program called The Frontier Fields. NASA's Great Observatories are teaming up to look deeper into the universe than ever before. The foreground clusters range in distance from 3 billion to 5 billion light-years from Earth. (c) NASA/ESA

NASA’s great observatories combine to probe deeper in the Universe

These are NASA Hubble Space Telescope natural-color images of four target galaxy clusters that are part of an ambitious new observing program called The Frontier Fields. NASA's Great Observatories are teaming up to look deeper into the universe than ever before.  The foreground clusters range in distance from 3 billion to 5 billion light-years from Earth. (c) NASA/ESA

These are NASA Hubble Space Telescope natural-color images of four target galaxy clusters that are part of an ambitious new observing program called The Frontier Fields. NASA’s Great Observatories are teaming up to look deeper into the universe than ever before. The foreground clusters range in distance from 3 billion to 5 billion light-years from Earth. (c) NASA/ESA

Each of NASA’s Great Observatories – Hubble, Spitzer and Chandra – have been designed to peer through the Universe in a characteristic manner. The telescopes have provided along the years massive amount of astronomical data and have helped scientists make important discoveries. What if you combine each of the telescopes’ strong points to assemble one massive probe capable of seeing farther in the Universe than ever before? That’s exactly what  The Frontier Fields ambitious space program will undertake in the following three years, combining the observational power of all three major NASA telescopes along with natural gravitational lenses to study six massive clusters of galaxies.

“The Frontier Fields program is exactly what NASA’s Great Observatories were designed to do; working together to unravel the mysteries of the universe,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “Each observatory collects images using different wavelengths of light with the result that we get a much deeper understanding of the underlying physics of these celestial objects.”

The program will tackle galaxy clusters that are among the most massive assemblages of matter known. Because of their humongous mass, these galaxy clusters (hundreds to thousands of galaxies bound together by gravity), exert powerful gravitational fields which can be used to brighten and magnify more distant galaxies so they can be observed. This is called gravitational lensing  and because of it  light rays that would have otherwise not reached the observer are bent from their paths and towards the observer.

Pandora’s Cluster. (c) NASA

Pandora’s Cluster. (c) NASA

The first object the astronomers will be directing their view towards is  Abell 2744 or  Pandora’s Cluster. This giant cluster is actually thought to be the result of four distinct galaxy clusters that piled-up over the span of 350 million years.  Studying this cluster, astronomers hope they can discover galaxies that were formed just a few hundred millions years after the Big Bang.

“The idea is to use nature’s natural telescopes in combination with the great observatories to look much deeper than before and find the most distant and faint galaxies we can possibly see,” said Jennifer Lotz, a principal investigator with the Space Telescope Science Institute in Baltimore, Md.

Each Great Observatory will have its role to play. Hubble tells astronomers in which way to direct their view and how many galaxies or stars are born in a system. Spitzer can relay how old these cosmic bodies are. Chanda, using its  X-ray wavelengths instruments, will image the clusters and tell astronomers what their  mass and gravitational lensing power is.

“We want to understand when and how the first stars and galaxies formed in the universe, and each great observatory gives us a different piece of the puzzle,” said Peter Capak, the Spitzer principal investigator for the Frontier Fields program at NASA’s Spitzer Science Center at the California Institute of Technology, Pasadena.

 

The inset at left shows a close-up of the young dwarf galaxy. This image is a composite taken with Hubble's WFC 3 and ACS. Credit: NASA, ESA, and M. Postman and D. Coe (STScI) and CLASH Team.

Farthest known object in the Universe is 13.3 billion years old

The inset at left shows a close-up of the young dwarf galaxy. This image is a composite taken with Hubble's WFC 3 and ACS. Credit: NASA, ESA, and M. Postman and D. Coe (STScI) and CLASH Team.

The inset at left shows a close-up of the young dwarf galaxy. This image is a composite taken with Hubble’s WFC 3 and ACS. Credit: NASA, ESA, and M. Postman and D. Coe (STScI) and CLASH Team.

NASA scientists have announced they have discovered the farthest object discovered so far in the Universe, a 13.3 billion old galaxy or a mere 420 million years after the Big Bang.

That’s not to say that its 13.3 billion light years away from Earth, since the Universe has expanded greatly since then and the actual distance might be much greater than this figure. It means that light took 13.3 billion years to reach us.

The galaxy has been dubbed  MACS0647-JD and was discovered using a combination of NASA’s Hubble and Spitzer space telescopes, along with gravitational lensing – an interstellar technique that uses distant galaxies to create a zooming effect for the light that passes through them. Without gravitational lensing, this discovery would have been impossible with the current technology employed in telescopes.

“This [magnification galaxy] does what no manmade telescope can do,” Marc Postman, of Baltimore’s Space Telescope Institute, said in a release. “Without the magnification, it would require a Herculean effort to observe this galaxy.”

Essentially, the scientists have looked into the past – 13.3 billion years into the past. What they saw was a galaxy that was only a tiny fraction of the Milky Way. More exactly, it’s been estimated as being only 600 light years wide. For compassion, the Large Magellanic Cloud, a dwarf galaxy companion to the Milky Way, is 14,000 light-years wide. Our Milky Way is 150,000 light-years across.

Since then it has most likely grown, and even collided already with other galaxies. The previous record holder was a gamma ray burst just 600 million years after the Big Bang.

“Over the next 13 billion years, it may have dozens, hundreds, or even thousands of merging events with other galaxies and galaxy fragments,” Dan Coe, lead author of the study announcing the discovery, said in a release. “This object may be one of many building blocks of a galaxy.”

source: NASA

Quasar Faint Light

Quasars “snack” regularly, instead of “feasting in one gulp”

Artist's rendering of ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun. (c) ESO/M. Kornmesser

Artist's rendering of ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun. (c) ESO/M. Kornmesser

Quasars are some of the brightest objects in the Universe. Their formed after black holes devour captured material, like  gas dust and stars that come too close, and release bright light that can be seen across the universe. Most of the popular astronomy today is orientated towards the particularly extremely bright quasars; those formed in a singular event consisting of the merger of a black holes with other galaxies that drive huge streams of gas and dust into their centers.

A new NASA survey however has found that more often than not, there are fainter quasars that thrive in normal-looking spiral galaxies, making the bulk of the Universe’s quasar population. A census of 30 quasar host galaxies was conducted by  Hubble and Spitzer. Of these, 26 of the host galaxies show no particular sign of a cosmic collision with neighbors, an event usually signaled by distorted shapes. Of the rest,  only one galaxy in the sample shows evidence of an interaction with another galaxy.

“The brilliant quasars born of galaxy mergers get all the attention because they are so bright and their host galaxies are so messed up,” Yale University astronomer Kevin Schawinski said in a statement. “But the typical bread-and-butter quasars are actually where most of the black-hole growth is happening. They are the norm, and they don’t need the drama of a collision to shine.”

Quasar Faint Light

Four photos merged together taken by the Hubble Space Telescope, each depicting galaxies kept at bay by quasars at their center. Three of these galaxies (top right, bottom left, and bottom right) are normal and show no signs of past collisions, while the top left galaxy's irregular shape suggests it collided with a neighbor. (c) NASA, ESA

The quasars were observed in infrared light, which can pierce through the dust that often shrouds galaxies in optical light. They’re estimated to have existed roughly 8 billion to 12 billion years ago, a time when black hole growth was at a peak.

Black holes are slow eaters, not excited gobblers. No word on table manners, though

What makes this discovery really important is the fact that it now offers substantial proof, backing the claim that the growth of most massive black holes in the early universe was fueled by small, long-term events rather than dramatic short-term major mergers. What does it take to make a quasar, though? According to the NASA researchers, typically a black hole doesn’t need too much gas to unleash a quasar.

“There’s more than enough gas within a few light-years from the center of our Milky Way to turn it into a quasar,” Schawinski explained. “It just doesn’t happen. But it could happen if one of those small clouds of gas ran into the black hole. Random motions and stirrings inside the galaxy would channel gas into the black hole. Ten billion years ago, those random motions were more common and there was more gas to go around. Small galaxies also were more abundant and were swallowed up by larger galaxies.”

Not very much is known about quasar, particularly because they’re so difficult to observe and study. This might change once with the launch of the James Webb Telescope, a massive, cutting-edge space telescope designed to orbit 1 million miles from Earth, where it would observe the mid-infrared portion of the electromagnetic spectrum.

To get to the heart of what kinds of events are powering the quasars in these galaxies, we need the Webb telescope. Hubble and Spitzer have been the trailblazers for finding them.”

Findings were published in the journal Monthly Notices of the Royal Astronomical Society.

via space.com

Glow harbors first objects in the universe. infrared imaged by Spitzer Space Telescope

Ethereal glow might harbor the Universe’s first objects

Glow harbors first objects in the universe. infrared imaged by Spitzer Space Telescope

First discovered in 2005, and then studied in more depth since 2007, NASA scientists have finally isolated the ethereal glow thought to originate from the very first objects in the Universe with the highest precision yet.

As seen in the image above, depicted in orange and red, the ‘lumpy’ infrared glow was observed using the ever faithful Spitzer Space Telescope, a remarkable device which has so far delivered numerous valuable scientific data about the cosmos. The scientists suggest the glow was given off by wildly massive stars or voracious black holes. The exact source can not be pinpointed with the available technology today, but what seems rather certain is that it originated from the very first objects in the Universe 13 billion years ago, shortly, in cosmic time that is, after the “Big Bang“, which is theorized to had occurred 13.7 billion years ago.

“All we can say is that these sources do not exist among the known galaxy populations, which have been observed to very early times (large distances),” said Alexander “Sasha” Kashlinsky, a NASA scientist who led the team that made the discovery. “This likely puts us within the first half-giga-year of the universe’s evolution, the epoch of first stars.”

The intriguing glow, known as cosmic infrared background, was first sighted by Spitzer in 2005, but only in recent years was the telescope able to isolate it. Scientists directed Spitzer at a region of interest in the sky — near the constellation Boötes — and studied it for over 400 hours, after which they carefully subtracted all of the known stars and galaxies in the images.

What remained were faint patterns of light with several telltale characteristics of the cosmic infrared background.

“These objects would have been tremendously bright,” says Alexander Kashlinsky of NASA’s Goddard Space Flight Center.

“We can’t yet directly rule out mysterious sources for this light that could be coming from our nearby universe, but it is now becoming increasingly likely that we are catching a glimpse of an ancient epoch. Spitzer is laying down a roadmap for NASA’s upcoming James Webb Telescope, which will tell us exactly what and where these first objects were.”

Their first light would have originated at visible or even ultraviolet wavelengths and then, because of the expansion of the universe, stretched out to the longer, infrared wavelengths observed by Spitzer. The telescope, however, has a short-wavelength view and thus can not answer unambiguously whether these objects were stars, black holes, galaxies or some previously unknown celestial formation. The new study measures this cosmic infrared background out to scales equivalent to two full moons – significantly larger than before. They plan to explore more patches of sky in the future.

“We hope to achieve this in the coming years (or months),” Kashlinsky said.

Such investigations would have access to a broader picture, and thus answers as well, once with the deployment of the highly anticipated James Webb Space Telescope, slated for launch in 2018. The James Webb Telescope is a massive, cutting-edge space telescope designed to orbit 1 million miles from Earth, where it would observe the mid-infrared portion of the electromagnetic spectrum. This would make it capable of gazing through some of the earliest forms of the Universe.

“This is one of the reason’s we are building the James Webb Space Telescope,” says Glenn Wahlgren, Spitzer program scientist. “Spitzer is giving us tantalizing clues, but James Webb will tell us what really lies at the era where stars first ignited.”

The findings were reported in the journal The Astrophysical Journal.

[source]

Combined visible and infrared images of the Sombrero Galaxy. Infrared: NASA/JPL-Caltech/R. Kennicutt (University of Arizona), and the SINGS Team Visible: Hubble Space Telescope/Hubble Heritage Team

The Sombrero Galaxy is actually made up of two galaxies in one, infrared survey finds

Combined visible and infrared images of the Sombrero Galaxy. Infrared: NASA/JPL-Caltech/R. Kennicutt (University of Arizona), and the SINGS Team Visible: Hubble Space Telescope/Hubble Heritage Team

Combined visible and infrared images of the Sombrero Galaxy. Infrared: NASA/JPL-Caltech/R. Kennicutt (University of Arizona), and the SINGS Team Visible: Hubble Space Telescope/Hubble Heritage Team

Astronomers classify galaxies into three basic types: elliptical (flat, elongated shape), spiral (most easily recognizable and common – described by their disk shape and outward spiraling arms) and irregular (usually described by a irregular shape, typical to very young galaxies). One of the most fascinating galaxies known to man is the Sombrero galaxy, shaped like a hat hence it’s name. For a long time, astronomers have thought the Sombrero galaxy was a spiral galaxy; a new infrared survey by the Spitzer Telescope, however, reveals that the galaxy’s nature is more complex than previously thought. New data suggests that the Sombrero Galaxy is actually two types of galaxies in one!

So far, the galaxy has only been observed using optical telescopes, which showed it as a disk-shaped galaxy, wrapped by a beautiful glowing halo. Until recently, astronomers thought this halo was small and light, typical of spiral galaxies. Spitzer’s observations, however, which used infrared light to peer through clouds of dust and gas which obstructed previous optical observations, show that the halo around the Sombrero Galaxy is larger and more massive than previously thought, indicative of a giant elliptical galaxy. So, spiral or elliptical? The Sombrero Galaxy is both it seems.

“The Sombrero is more complex than previously thought,” says Dimitri Gadotti of the European Southern Observatory in Chile. “The only way to understand all we know about this galaxy is to think of it as two galaxies, one inside the other.”

It’s unlikely that the giant elliptical galaxy swallowed a spiral disk, as this would cause the destruction of the latter. Instead, the researchers involved in the study suggest that a giant elliptical galaxy was inundated with gas more than nine billion years ago.

“This poses all sorts of questions,” said Rubén Sánchez-Janssen from the European Southern Observatory. “How did such a large disk take shape and survive inside such a massive elliptical? How unusual is such a formation process?”

This might explain a mystery which surrounded the Sombrero Galaxies and had puzzled scientists for a while. The galaxy has over 2,000   globular clusters, when most spiral galaxies only have a few hundred – the new found two in one galaxy hypothesis seems to explain the anomaly.

The galaxy might not be alone in its “split-personality” nature.  Centaurus A, appears also to be an elliptical galaxy with a disk inside it, although its disk doesn’t contain many stars.

A spectrum from the European Space Agency's Infrared Space Observator superim. (c) NASA, C.R. O'Dell, S.K. Wong (Rice University) posed on an image of the Orion nebula.

Stars spew out organic matter into space – life may have its origin in star dust

A spectrum from the European Space Agency's Infrared Space Observator superim. (c) NASA, C.R. O'Dell, S.K. Wong (Rice University) posed on an image of the Orion nebula.

A spectrum from the European Space Agency's Infrared Space Observator superim, on top of the Orion nebula. (c) NASA, C.R. O'Dell, S.K. Wong (Rice University) posed on an image of the Orion nebula.

A new study published by researchers at University of Hong Kong has produced controversial waves among the astronomy community, as it claims, backed by sound evidence, that organic matter can be created naturally by stars and travel through out the universe via interstellar dust.

It’s somewhat hard to believe, even picture, how organic matter can be spewed out by stars without current or previous life being involved, however incredibly enough this is very much true – moreover, organic compounds seem to be everywhere!

The Hong Kong researchers first observed various stars of different evolutionary stages and studied the well-known but mysterious infrared emissions, called Unidentified Infrared Emission (UIE). What they found was that highly complex organic compounds are ejected into space by stars under the form of cosmic dust at a surprisingly high pace, filling interstellar space. Some compounds’ chemical structures resemble the makeup of coal and petroleum, the study’s lead author Sun Kwok, of the University of Hong Kong, said.

“What impressed me most is that complex organics are easily formed by stars, they are everywhere in our own galaxy and in other galaxies,” Kwok told SPACE.com in an email interview. “Nature is much more clever than we had imagined.”

Previously, UIE features were thought to be emitted by polycyclic aromatic hydrocarbon, or PAH, molecules – simple molecules made of hydrogen and carbon. The Hong Kong scientists’ recently published paper in the journal Nature suggests this hypothesis is incorrect.

Capitalizing on data furnished by the European Space Agency‘s Infrared Space Observatory and NASA‘s Spitzer Space Telescope, the researchers found that the UIE features are not emitted by PAH molecules, but by complex organic compounds. These emissions occur, it seems, during the protoplanetary nebula stage and grew stronger as the stars matured into the planetary nebula phase.

“We therefore know that these organics are being made in the circumstellar stellar environment,” Kwok said.

Curiously enough, scientists have found these organic compounds observed in jetissoned star dust is very chemically similar to those found on meteorites. The primordial birth place of meteors lies in space rocks, and cosmic dust could easily enrich the organic coating, or place it there in the first place.

“It is quite possible that the organics in meteorites are remnants of star dust in the solar nebula,” he explained. “The star dust [was] ejected by nearby planetary nebula[s] and survived the journey across the galaxy.”

A not too far off hypothesis could be emitted,thus. Namely, during the Earth’s early stage in history when its atmosphere was still too thin to protect the planet from the hazards of the solar system and meteor showers rained constantly, there might exist a possibility that the organic compounds brought in by meteors could have played a major role in the formation of life. Basically, if this is true, we’re all star dust – children of the stars.

Kwok and colleagues intend to continue analyzing additional infrared observations to better pin down the chemical structure of organic star dust.

“Coal and kerogen are products of life and it took a long time for them to form,” Kwok said. “How do stars make such complicated organics under seemingly unfavorable conditions and [do] it so rapidly?”

source

RCW 120 is just one of many such ringed nebulas found in the Milky Way. (c) NASA

Stunning image of “O-ring” shapped nebula

RCW 120 is just one of many such ringed nebulas found in the Milky Way. (c) NASA

RCW 120 is just one of many such ringed nebulas found in the Milky Way. (c) NASA

The brilliant image from above was captured by Spitzer space telescope and depicts a ring shaped region formed by hot gas and glowing dust.

Dubbed RCW 120, the nebula lies about 4,300 light-years away from Earth, and is located in the constellation Scorpius, just above the plane of the galaxy. The wavelength emited by the nebula is far within the infrared spectrum, which makes it totally invisible to a human observer, but perfectly bright for Spitzer’s infrared detectors.

It’s interesting “O-ring” shape, scientists believe, comes from the heat of a cluster of giant “O” type stars at the center of galaxy. These star are the most massive and bright stars so far known to man, which emit an intense ultraviolet light. But the captioned image example is only one of the slew of similar nebulas the Spitzer telescopes finds everyday.

So many, in fact, that the scientific team leading the Spitzer project are calling out “citizen scientists” to help identify and classify. As such, anyone interested in helping catalog findings such as these are invited to visit the Milky Way Project website.

140 Earth-like planets discovered in the Milky Way by Kepler

An artists rendering of what our galaxy might look as viewed from outside our Galaxy. Our sun is about 25,000 light years from the center of our galaxy. The cone illustrates the neighborhood of our galaxy that the Kepler Mission will search to find habitable planets. Credit: Jon Lomberg.

Last week at the latest TEDGlobal conference in Oxford, astronomer Dimitar Sassilov, professor of astronomy at Harvard University and a distinguished member of the Kepler space telescope science team, unveiled some incredible results gathered by our eyes and ears in the galaxy. Kepler’s most recent reported downloaded conferred some incredible statistics, among which most importantly the discovery of: 706 potential new planets and five new solar systems, all found within the 150,000+ stars Kepler has studied so far since its 4 year mission began January last year.

Out of the whole data transmitted by Kepler nothing stands out more than the discovery of 140 potential Earth-like planets – these are planets are rocky, and quite possibly may contain both land and water. Conditions which could allow simple life forms to develop.

Astronomers are now keen to further extend their efforts towards studying multi-planetery solar systems since they are considered most likely to harbor the necessary conditions an Earth-like planet needs, and in consequence alien life.

“Life is a chemical system that really needs a smaller planet, water and rocks and lots of complex chemistry to originate emerge and survive.

There is a lot more work we need to do with this but the statistical result is loud and clear and it is that planets like our own Earth are out there.

Our own Milky Way galaxy is rich in thee kinds of planets,” stated Sasselov.

Kepler also shows that planets, as presumed, are indeed quite common, but unfortunately quantity is of no importance, but size distribution. As such NASA has selected 60 of Kepler’s finds for further detailed studying through the use of ground-based instruments, in conjuction with the Hubble and Spitzer space telescopes. Vital data is expected in February.

“The next step after Kepler will be to study the atmospheres of the planets and see if we can find any signs of life,” said Dimitar Sasselov.

As inspiring as these new finds might prove to be, Lord Martin Rees, professor of cosmology and astrophysics at Cambridge University, warns it will take decades to photograph such planets.

He said: “If there is other life elsewhere in the universe, the most obvious place to look would be a planet like the Earth.”

“I’m sure that in two or three years we’ll know from the Kepler observations that there are many other planets like the Earth orbiting other stars.”
“But I think it may be 20 years before we get an image of a planet. As to whether they will have life on them, I would not take any bets at all.”

UPDATE: as a worthy update, since this article is rather old, it’s worth mentioning that since this post was written a number of advances in astronomy and astrophysics have been made. To stay on topic though – namely on Kepler –  the most recent findings suggest that our very own galaxy, the Milky Way, is host to billions of Earth-like planets. Now, that’s something to put into perspective, isn’t it?