A group of international astronomers in the UK, France and the USA, led by the University of Leicester, have found proof to confirm the distance and brightness of the most extreme ultra-luminous X-ray source, which may herald a new type of Black Hole.

The X-ray source, HLX-1, is the most extreme member of an extraordinary class of objects — the ultra-luminous X-ray sources — and is located in the galaxy ESO 243-49 at a distance of ~300 million light years from the Earth.

The astronomers’ findings confirm that the extreme luminosity (which is a factor of ~100 above most other objects in its class, and a factor of ~10 higher than the next brightest ultra-luminous X-ray source) is correct.

This is forcing scientists to rethink their theories on the maximum brightness of ultra-luminous X-ray sources, and provides support to the idea that HLX-1 may contain an intermediate mass black hole.

This latest result will be reported September 8 in the scientific journal, The Astrophysical Journal.

Using the European Southern Observatory’s (ESO’s) Very Large Telescope (VLT) in Chile, the team have obtained an optical spectrum of their record breaking ultra-luminous X-ray source (HLX-1) in the distant galaxy ESO 243-49.

Their findings enable them to show conclusively that HLX-1 is indeed located within this galaxy, and is neither a foreground star nor a background galaxy. The main implication of this discovery is that ultra-luminous X-ray sources such as HLX-1 can be brighter than was originally thought, which is consistent with at least the brightest of them hosting intermediate mass black holes.

A black hole is an ultra-dense object with such a powerful gravitational field that it absorbs all the light that passes near it and reflects nothing.

While astrophysicists have suspected that an intermediate class of black hole might exist, with masses between a hundred and several hundred thousand times that of the Sun, such black holes had not previously been reliably detected and their existence has been fiercely debated among the astronomical community.

The VLT enabled the team of researchers to confirm the detection of HLX-1 in optical wavelengths and to measure a precise distance to it.

The lead author of the paper reporting this result, Dr Klaas Wiersema of Leicester’s Department of Physics and Astronomy, commented: "After our earlier discovery of the very bright X-ray source, we were very keen to find out just how far away it really is, so that we can work out how much radiation this black hole produces.

"We could see on images taken with big telescopes that a faint optical source was present at the location of the X-ray source, located near the core of a large and bright galaxy.

"We suspected that this faint optical source was directly associated with the X-ray source, but to be sure we had to study the light of this source in detail, using the Very Large Telescope in Chile.

"The data we got from the VLT were of a very high quality, and allowed us to separate the light of the big, bright galaxy from that of the faint optical source.

"Much to our delight we saw in the resulting measurements exactly what we were hoping for: the characteristic light of hydrogen atoms was detected allowing us to accurately measure the distance to this object. This provided conclusive proof that the black hole was indeed located inside the big, bright galaxy, and that HLX-1 is the brightest ultra-luminous X-ray source known.

"Now that we have established the distance to this black hole and now we know where it lives, we would like to find out what makes this source so bright, and how it ended up in this big galaxy."

This is a very important result as it is consistent with the idea that HLX-1 contains an intermediate mass black hole. Ultra-luminous X-ray sources are among the most promising candidates for intermediate mass black holes, with masses between stellar mass black holes (around ~3-20 times the mass of the Sun) and the super-massive black holes found in the centres of most galaxies (around 1 million — 1 billion times the mass of the Sun).

The research team can now conclusively prove that HLX-1 is not in our own Galaxy, nor is it a super-massive black hole in the centre of a distant background galaxy. This result also confirms that it really is as bright as they thought it was.

Dr Didier Barret, of the Centre d’Etude Spatiale des Rayonnements in France, commented: "The XMM-Newton and Swift X-ray observatories are keeping a close eye on this source. The latest data, which was obtained while HLX-1 was very faint, indicates that it is behaving in a very similar way to stellar mass black holes in our own Galaxy, but at a level ~100 — 1,000 times brighter."

Dr Sean Farrell, also in the Leicester Department of Physics and Astronomy, commented: "This is very difficult to explain without the presence of an intermediate mass black hole of between ~500 and 10,000 times the mass of the Sun. HLX-1 is therefore (so far!) weathering the scrutiny of the international astronomy community."

The centres of most galaxies are thought to contain super-massive black holes, and these powerhouses have an enormous impact on the surrounding galaxy. Super-massive black holes deposit an immense amount of energy into their host galaxies, which has dramatic consequences for the formation of stars and the growth of the galaxy as a whole. Intermediate mass black holes may be the building blocks of super-massive black holes.

"Understanding how super-massive black holes form and grow is thus crucial to our comprehension of the formation and evolution of galaxies, which in turn goes part of the way to answering one of the really big questions: How did our own Galaxy form and evolve?

"We are very pleased with this result, as it confirms our original discovery of the record breaking ultra-luminous X-ray source. In order to ensure the success of this project, we carefully prepared the VLT observations using data from the US-operated Magellan Telescopes. The VLT data analysis was especially complicated on this project, as it is very difficult to disentangle the signature in optical wavelengths of HLX-1 from the bright galaxy in which it lies.

"This work relied heavily on the expertise of researchers at the University of Leicester, and is testament to the high level of skills that are concentrated in our department, which works on some of the biggest questions in astronomy today. This is fitting as we are currently celebrating the 50th anniversary of the founding of the astronomy group here at Leicester."

Whether all ultra-luminous X-ray sources contain intermediate mass black holes is still quite uncertain. Dr Farrell’s research team will continue studying HLX-1 in order to understand how it formed, where it is located, and what is feeding it.

In order to do this they have been granted time on the Hubble Space Telescope to take the highest ever resolution images of this host galaxy, which will allow them to investigate in detail the nature of the environment around HLX-1 and the galaxy which hosts it. Once the Hubble observations are performed, most of the great observatories would have been used to study this source.

The next step will be to find out if there are more objects as extreme as this one, and to compare what they know about HLX-1 with the larger population of ultra-luminous X-ray sources. This will help them understand how many intermediate mass black holes might be out there, and where they are likely to find them.

In recent decades documented biological changes in the far Northern Hemisphere have been attributed to global warming, changes from species extinctions to shifting geographic ranges. Such changes were expected because warming has been fastest in the northern temperate zone and the Arctic.

But new research published in the Oct. 7 edition of Nature adds to growing evidence that, even though the temperature increase has been smaller in the tropics, the impact of warming on life could be much greater there than in colder climates.

The study focused on ectothermic, or cold-blooded, organisms (those whose body temperature approximates the temperature of their surroundings). Researchers used nearly 500 million temperature readings from more than 3,000 stations around the world to chart temperature increases from 1961 through 2009, then examined the effect of those increases on metabolism.

“The expectation was that physiological changes would also be greatest in the north temperate-Arctic region, but when we ran the numbers that expectation was flipped on its head,” said lead author Michael Dillon, an assistant professor of zoology and physiology at the University of Wyoming.

Freshwater is flowing into Earth’s oceans in greater amounts every year, a team of researchers has found, thanks to more frequent and extreme storms linked to global warming. All told, 18 percent more water fed into the world’s oceans from rivers and melting polar ice sheets in 2006 than in 1994, with an average annual rise of 1.5 percent.

“That might not sound like much — 1.5 percent a year — but after a few decades, it’s huge,” said Jay Famiglietti, UC Irvine Earth system science professor and principal investigator on the study, which will be published this week in Proceedings of the National Academy of Sciences. He noted that while freshwater is essential to humans and ecosystems, the rain is falling in all the wrong places, for all the wrong reasons.

“In general, more water is good,” Famiglietti said. “But here’s the problem: Not everybody is getting more rainfall, and those who are may not need it. What we’re seeing is exactly what the Intergovernmental Panel on Climate Change predicted — that precipitation is increasing in the tropics and the Arctic Circle with heavier, more punishing storms. Meanwhile, hundreds of millions of people live in semiarid regions, and those are drying up.”

New research challenges the controversial theory that an ancient comet impact devastated the Clovis people, one of the earliest known cultures to inhabit North America.

Writing in the October issue of Current Anthropology, archaeologists Vance Holliday (University of Arizona) and David Meltzer (Southern Methodist University) argue that there is nothing in the archaeological record to suggest an abrupt collapse of Clovis populations. "Whether or not the proposed extraterrestrial impact occurred is a matter for empirical testing in the geological record," the researchers write. "Insofar as concerns the archaeological record, an extraterrestrial impact is an unnecessary solution for an archaeological problem that does not exist."

The comet theory first emerged in 2007 when a team of scientists announced evidence of a large extraterrestrial impact that occurred about 12,900 years ago. The impact was said to have caused a sudden cooling of the North American climate, killing off mammoths and other megafauna. It could also explain the apparent disappearance of the Clovis people, whose characteristic spear points vanish from the archaeological record shortly after the supposed impact.

As evidence for the rapid Clovis depopulation, comet theorists point out that very few Clovis archaeological sites show evidence of human occupation after the Clovis. At the few sites that do, Clovis and post-Clovis artifacts are separated by archaeologically sterile layers of sediments, indicating a time gap between the civilizations. In fact, comet theorists argue, there seems to be a dead zone in the human archaeological record in North America beginning with the comet impact and lasting about 500 years.

But Holliday and Meltzer dispute those claims. They argue that a lack of later human occupation at Clovis sites is no reason to assume a population collapse. "Single-occupation Paleoindian sites — Clovis or post-Clovis — are the norm," Holliday said. That’s because many Paleoindian sites are hunting kill sites, and it would be highly unlikely for kills to be made repeatedly in the exact same spot.

"So there is nothing surprising about a Clovis occupation with no other Paleoindian zone above it, and it is no reason to infer a disaster," Holliday said.

In addition, Holliday and Meltzer compiled radiocarbon dates of 44 archaeological sites from across the U.S. and found no evidence of a post-comet gap. "Chronological gaps appear in the sequence only if one ignores standard deviations (a statistically inappropriate procedure), and doing so creates gaps not just around [12,900 years ago] but also at many later points in time," they write.

Sterile layers separating occupation zones at some sites are easily explained by shifting settlement patterns and local geological processes, the researchers say. The separation should not be taken as evidence of an actual time gap between Clovis and post-Clovis cultures.

Holliday and Meltzer believe that the disappearance of Clovis spear points is more likely the result of a cultural choice rather than a population collapse. "There is no compelling data to indicate that North American Paleoindians had to cope with or were affected by a catastrophe, extraterrestrial or otherwise, in the terminal Pleistocene," they conclude.

History of Clovis people:

The Clovis culture is a prehistoric Native American culture that first appears in the archaeological record of North America around 13,500 years ago, at the end of the last ice age.

The culture is named for artifacts found near Clovis, New Mexico, where the first evidence of this tool complex was excavated in 1932. Earlier evidence included a mammoth skeleton with a spear-point in its ribs, found by a cowboy in 1926 near Folsom, New Mexico. Clovis sites have since been identified throughout all of the contiguous United States, as well as Mexico and Central America.

The Clovis people, also known as Paleo-Indians, are generally regarded as the the first human inhabitants of the New World, and ancestors of all the indigenous cultures of North and South America. However, this view has been recently contested by various archaeological finds which are claimed to be much older.

There are a number of controversial sites vying for the position of the earliest site in the region. The best evidence, however, suggests that a society of hunters and gatherers known as Clovis People were the first to settle in the Southwest, probably sometime before 9,500 B.C. The Clovis People were so named after the New Mexico town, site of the first discovery in 1932, near Clovis, N.M.

Since the mid 20th century, the standard theory among archaeologists has been that the Clovis people were the first inhabitants of the Americas. The primary support of the theory was that no solid evidence of pre-Clovis human inhabitation has been found. According to the standard accepted theory, the Clovis people crossed the Beringia land bridge over the Bering Strait from Siberia to Alaska during the period of lowered sea levels during the ice age, then made their way southward through an ice-free corridor east of the Rocky Mountains in present-day western Canada as the glaciers retreated.

The culture lasted for about a half a millennium, from about 11,200 to 10,900 years ago. People of the Clovis culture were successful, efficient big-game hunters and foragers. Judging from sites on the North American Great Plains, the Clovis people were skilled hunters of huge animals, especially Ice Age mammoths and mastodons.

It is generally accepted that Clovis people hunted mammoth: sites abound where Clovis points are found mixed in with mammoth remains. Whether they drove the mammoth to extinction via overhunting them – the so-called Pleistocene overkill hypothesis – is still an open, and controversial, question, keeping in mind that Archaeology is purely a theoretical endeavor.

A global analysis of extinction risk for the world’s plants, conducted by the Royal Botanic Gardens, Kew together with the Natural History Museum, London and the International Union for the Conservation of Nature (IUCN), has revealed that the world’s plants are as threatened as mammals, with one in five of the world’s plant species threatened with extinction.

The study is a major baseline for plant conservation and is the first time that the true extent of the threat to the world’s estimated 380,000 plant species is known, announced as governments are to meet in Nagoya, Japan in mid-October 2010 to set new targets at the United Nations Biodiversity Summit.

A 2008 Google Earth search led to the discovery of Kamil crater, one of the best-preserved meteorite impact sites ever found. Earlier this year, a gritty, sand-blown expedition reached the site deep in the Egyptian desert to collect iron debris and determine the crater’s age and origins.

One day within the last several thousand years, a rare metallic meteorite travelling over 12 000 km/hour smashed into Earth’s surface near what is today the trackless border region between Egypt, Sudan and Libya. The impact of the 1.3 m, 10-tonne chunk of iron generated a fireball and plume that would have been visible over 1000 km away, and drilled a hole 16 m deep and 45 m wide into the rocky terrain.

Since then, the crater had sat undisturbed by Earth’s geologic and climatic processes, which usually render all but the very largest terrestrial impact craters invisible. It was also, as far as is recorded, unseen by humans.

The threat of a significant impact has been on the minds of astronomers for decades. There have been movies of varying quality made on the subject.

However, the actual danger has been minimal. But now, scientists from NASA are worried that asteroid 1999 RQ36 might be on a collision course with Earth.

1999 RQ36 is the minor planet designation of an Apollo asteroid discovered by LINEAR in 1999. It has a mean diameter of approximately 560 meters, and has been observed extensively with the Arecibo Observatory Planetary Radar and the Goldstone Deep Space Network.

A recent dynamical study by Andrea Milani and collaborators has located a series of eight potential Earth impacts between 2169 and 2199. The cumulative probability of impact is dependent on poorly known physical properties of the object, but is not higher than 0.07% for all eight encounters. While the chances of impact are roughly 1 in 1000, the threat is real enough to make scientists anxious. The technology needed to deflect such an asteroid is in the theoretical phase of its evolution. And while, the collision won’t happen for another 170 years (if it happens at all), the development of such systems has always been all talk and no action.

To accurately assess RQ36′s probability of Earth impact will require a detailed shape model of the asteroid and at least several more years of radar and optical observations to determine the magnitude of the Yarkovsky acceleration.

Separately, RQ36 has been considered multiple times as the target of spacecraft missions, including OSIRIS, due to the low delta-v required to reach it from Earth orbit.

Should 1999 RQ36 reach Earth, the 560 metres wide rock would have devastating effects. Initially, the fallout would impact life for hundreds of miles in every direction. The long term effects are the greater worry however. With dust a debris launched into the atmosphere, light from the Sun would be irreversibly blocked. The results could mean the death of all life on Earth.

Dr. Michio Kaku often talks about these type of Hollywood scenarios. Provided we have enough time, the best course of action would be merely to nudge the asteroid off its trajectory. Accomplish that however you want to accomplish it, perhaps by landing a small device on the surface that has tiny booster rockets on there.

What you don’t want to do is blow it up since that will only put several destructive objects on a collision course with the planet.

Sounds pretty dire doesn’t it? Well, the truth of the matter is that all of that can be avoided with careful planning. But that means starting now and investing money into diversion technologies so that we are not scrambling at the last minute to devise a plan. That way, we are ready when 1999 RQ36 or some other object finds itself on a collision course with the rock we call home.