Tag Archives: quasar

Artist's impression of gas around a forming galaxy in a large computer simulation. The pristine gas detected by astronomers could lie in one of the filamentary regions. (c) Ceverino, Dekel, and Primack

Elemental gas clouds formed minutes after the Big Bang found

Artist's impression of gas around a forming galaxy in a large computer simulation. The pristine gas detected by astronomers could lie in one of the filamentary regions. (c) Ceverino, Dekel, and Primack

Artist's impression of gas around a forming galaxy in a large computer simulation. The pristine gas detected by astronomers could lie in one of the filamentary regions. (c) Ceverino, Dekel, and Primack

One of the fundamental backbones of the Big Bang theory states that after the rapid expansion of the Universe only the lightest elements were formed. A group of scientists stumbled across an amazing discovery recently when they found a gas cloud dating from the time of the early Universe exclusively made out of hydrogen and helium, proving another solid evidence that supports the current Universe formation model. This is the first time scientists have been able to observe an area without any metallic elements, and thus peek into the early universe.

The two gas clouds weren’t observed directly, but by means of spectral analysis of the light emitted by a distant quasar, which in its travels also happened to pass through these primordial traces of the Universe, estimated at being 13.7 billion years old. The location of the clouds has been estimated at around 2 billion light years away, however they were formed just minutes after the Bing Bang. Amazingly enough, these clouds remained unpolluted by other elements for 2 billion years.

This isn’t however the oldest trace of the Universe found so far. Other discoveries have found objects just one billion years old, but this particular research is of great importance, since it enforces one of the fundamental principles that constitute the Big Bang model, which states that only the first two elements on the periodic table, hydrogen and helium, existed in the very early universe.

“This is very good news because the existence of gas without metal has been predicted by the big bang theory but never observed,” UC Santa Cruz doctoral student Michele Fumagalli, who helped on the study, says. “So the fact that we are seeing these gases there is now empirical evidence that this theory is correct.”

It certainly surprised Christopher Howk, a physics professor at the University of Notre Dame, who wasn’t involved in the study. “I actually was kind of shocked that they found this, because I had kind of given up hope that they would find this anytime soon, especially the way they did.”

All the other heavy elements, like metals, came millions and billions of years later inside of stars.

“When a massive star runs out of its fuel it explodes in a supernovae,” John O’Meara, a professor at Saint Michael’s College in Vermont who was an author on the new study says. “The explosions are so violent that it kicks this stuff [heavy elements] out of the galaxy.”

Incited by this phenomenal find, scientists now are poised to enlist on primordial gas hunts, so that similar pockets of elemental gas can be studied. The research appears in this week’s Science. 

Artist impression of a quasar. (c) NASA/ESA

Enormous water reservoir found in space is bigger than 140 trillion earth oceans

Astronomers have discovered the largest body of water so far known, a reservoir of water floating in space around a ancient distant quasar,  holding 140 trillion times the mass of water in the Earth’s oceans.

Artist impression of a quasar. (c) NASA/ESA

Artist impression of a quasar. (c) NASA/ESA

Remarkably enough, the find was dated as being 12 billion light years away, only  1.6 billion light years farther from the Big Bang.

“Since astronomers expected water vapor to be present even in the early universe, the discovery of water is not itself a surprise,” said the Carnegie Institution in statement, one of the groups behind the findings, said.

The water cloud was found to be in the central regions of a faraway quasar.

“Quasars contain massive black holes that steadily consuming a surrounding disk of gas and dust; as it eats, the quasar spews out amounts of energy,” the Institution continued in its statement.

And a lot of it, I might add. Quasars are the most powerful known entities in space, with this particular one pumping out 1,000 trillion times more energy than our sun, and 65,000 times the whole of the Milky Way. The black hole found at the quasar’s center has a mass 20 billion times greater than the sun.

NASA scientist Matt Bradford has said, “The environment around this quasar is very unique in that it’s producing this huge mass of water. It’s another demonstration that water is pervasive throughout the universe, even at the very earliest times.”

RELATED: Most distant quasar in the known Universe found

While water vapors are known to be found through out the Universe, it’s not that common of a sight. In the Milky Way, water vapor surfaces are found only in particular regions a few light years across at most, however, the water in the distant quasar appears to be spread over hundreds of light years.

The find came as part of a quasar study called “APM 08279+5255”, which gathered on observations first commenced by NASA three years ago in 2008, made using an instrument called “Z-Spec” at the California Institute of Technology’s Submillimeter Observatory. The instrument is a 33-foot (10-meter) telescope near the summit of Mauna Kea in Hawaii.

“Breakthroughs are coming fast in millimeter and submillimeter technology, enabling us to study ancient galaxies caught in the act of forming stars and supermassive black holes,” says CU-Boulder associate professor Jason Glenn.

An image taken through red and blue filters of the. The object itself lies very close to the centre and is not visible in this picture, but many other, much closer, galaxies are seen in this wide-field view that spans about three degrees of sky. (c)ESO and Digitized Sky Survey 2. Acknowledgment: Davide De Martin

Most distant quasar in known Universe found

Astronomers have discovered the most distant quasar known so far, dubbed ULAS J1120+0641, powered by a supermassive black hole with a mass 2 billion times that of our sun – it’s also the brightest object in the known Universe.

An image taken through red and blue filters of the. The object itself lies very close to the centre and is not visible in this picture, but many other, much closer, galaxies are seen in this wide-field view that spans about three degrees of sky.  (c)ESO and Digitized Sky Survey 2. Acknowledgment: Davide De Martin

An image taken through red and blue filters of the. The object itself lies very close to the centre and is not visible in this picture, but many other, much closer, galaxies are seen in this wide-field view that spans about three degrees of sky. (c)ESO and Digitized Sky Survey 2. Acknowledgment: Davide De Martin

At a redshift of 7.1, placing it at only 770 million years after the Big Bang, the newly discovered quasar is so far away that its light probes the last part of the reionization era. It’s not the most distant known object in space, though. Other bodies have been found at a larger redshift, such as a gamma-ray burst at redshift 8.2 and a galaxy at redshift 8.6, however this quasar is still hundreds of times brighter than both.  The next most-distant quasar is seen as it was 870 million years after the Big Bang (redshift 6.4).

Because objects such as these are so far away, their light gets stretched by the expansion of the Universe, and the light which eventually reaches Earth falls in the infrared spectrum. ULAS J1120 was discovered by the European UKIRT Infrared Deep Sky Survey (UKIDSS), which uses UK’s dedicated infrared telescope in Hawaii. To find it, astronomers had to dig through data consisting in millions of objects in the UKIDSS database – eventually, their efforts were rewarded.

“It took us five years to find this object,” explains Bram Venemans, one of the authors of the study which will appear in Nature on 30 June 2011. “We were looking for a quasar with redshift higher than 6.5. Finding one that is this far away, at a redshift higher than 7, was an exciting surprise. By peering deep into the reionisation era, this quasar provides a unique opportunity to explore a 100-million-year window in the history of the cosmos that was previously out of reach.”

As far as distance goes, that of the quasar was determined from observations made with the FORS2 instrument on ESO’s Very Large Telescope (VLT) and instruments on the Gemini North Telescope. The instruments split the analyzed light into its most basic colours, from which scientists could read some very important facts. For once, the mass of the black hole at the centre of ULAS J1120+0641 is about two billion times that of the Sun. Which, considering its formation into the early Universe, hits contradicts the current leading theory regarding the growth of supermassive black holes, why says that they grow in mass at a slow build-up as they pull matter from their surrounds.

RELATED: Astronomers plot largest 3D  map of the Universe

“We think there are only about 100 bright quasars with redshift higher than 7 over the whole sky,” concludes Daniel Mortlock, the leading author of the paper. “Finding this object required a painstaking search, but it was worth the effort to be able to unravel some of the mysteries of the early Universe.”

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Serendipitous events show rare events in distant quasar

According to Murphy’s laws, all great discoveries happen by mistake. This is not the case here, but scientists had the opportunity to observe something they weren’t expecting at all. Astronomers at the University of California-Santa Cruz had the fortune of witnessing the birth of a young galaxy.

They were the first to observe the onset of a huge flow of gas from a quasar which is virtually equivalent to the very bright core of a very young and remote galaxy. The gas was expelled about 10 billion years ago and it was noticed only thanks to a sharp-eyed undergraduate.

“It was completely serendipitous,” said Fred Hamann, a UF astronomy professor. “In fact, the only way it could have happened is through serendipity.”

Quasars are actually very bright cores of young galaxies, and they contain what is called super massive black holes, which are about a billion times larger than our sun. We can see them in galaxies that are far away, and formed a very long time ago (even by geological time) and the light from them is just now reaching our planet.

The black holes are invisible but the cosmic material is not, and it also forms some disks which are the cause for the quasar’s light. But despite the fact that scientists deducted that such clouds of gas have to exist, they didn’t witness the coming into place of such a cloud. Daniel Progra, a physics professor at the University of Nevada points out how lucky this discovery is.

“I am most excited about this work,” he said. “We humans cannot directly monitor changes in quasars as they take very many years. Therefore, a discovery of a change over a few years is very interesting. It is not unexpected, but chances are very small.”

Hamann adds that this raises even more questions.

“One interesting question in astronomy is ‘how does the evolution of quasars relate to the evolution of galaxies?,’” he said. “The matter ejected from quasars might be the key to this relationship because it can disrupt or regulate the formation of galaxies around quasars. This discovery is a small piece of that story that we can see happening in real time, and what we are going to do now is keep watching.”

Dusty Winds and the Seeded Planets

 

space dust

There is still some debate around how life appeared here on Earth and it is hard to find undeniable proof.

But the findings from NASA‘s Spitzer Space Telescope suggest that space dust — the same stuff that makes up living creatures and planets — was manufactured in large quantities in the winds of black holes that populated our early universe. Another problem this could bring an answer to is that of where did all the dust in the young universe originate.

“We were surprised to find what appears to be freshly made dust entrained in the winds that blow away from supermassive black holes,” said Ciska Markwick-Kemper of the University of Manchester, U.K. Markwick-Kemper is lead author of a new paper appearing in an upcoming issue of the Astrophysical Journal Letters. “This could explain where the dust came from that was needed to make the first generations of stars in the early universe.”.

Space dust is very important because it forms planets, stars, galaxies and even life as we know it – there’s a lot of truth to “we are all space dust”.

The dust which is close to us was piped out by dying stars that were once a lot like our sun. But what produced it when the universe was just a toddler is hard to say. Some scientists claim that short-lived, massive exploding stars, or supernovae, might be the source of this mysterious dust; others claim that a type of energetic, growing supermassive black hole, called a quasar, could be a contributing factor. A quasar (contraction of QUASi-stellAR radio source) is an extremely bright and distant active galactic nucleus. All observed spectra have shown considerable redshifts and they lie at great distances from us, the closest being 240 Mpc (780 million ly).

“Quasars are like the Cookie Monster,” said co-author Sarah Gallagher of the University of California at Los Angeles, who is currently a visiting astronomer at the University of Western Ontario, Canada. “They are messy eaters, and they can consume less matter than they spit out in the form of winds.”.

But nobody can say for sure that quasars are or are not what created enough dust to explain what is observed in the early universe. That goes for supernovae as well; so the debate is not cold. The team used Spitzer’s infrared spectrograph instrument to split apart infrared light from the quasar and look for signs of various minerals. They found a mix of the ingredients that make up glass, sand, marble and even rubies and sapphires. While the mineral constituting glass was expected, the minerals for sand, marble and rubies were a surprise. Those minerals are not typically detected floating around galaxies, suggesting they could have been freshly formed in the winds rushing away from the quasar.

“Supernovae might have been more important for creating dust in some environments, while quasars were more important in others,” said Markwick-Kemper. “For now, we are very excited to have identified the different species of dust in a quasar billions of light-years away.”. The study is of great importance.