Month: February 2018

Astrophysicists Discover Planets In Extragalactic Galaxies Using Microlensing

A University of Oklahoma astrophysics team has discovered for the first time a population of planets beyond the Milky Way galaxy. Using microlensing — an astronomical phenomenon and the only known method capable of discovering planets at truly great distances from the Earth among other detection techniques — OU researchers were able to detect objects in extragalactic galaxies that range from the mass of the Moon to the mass of Jupiter.

Xinyu Dai, professor in the Homer L. Dodge Department of Physics and Astronomy, OU College of Arts and Sciences, with OU postdoctoral researcher Eduardo Guerras, made the discovery with data from the National Aeronautics and Space Administration’s Chandra X-ray Observatory, a telescope in space that is controlled by the Smithsonian Astrophysical Observatory.

“We are very excited about this discovery. This is the first time anyone has discovered planets outside our galaxy,” said Dai. “These small planets are the best candidate for the signature we observed in this study using the microlensing technique. We analyzed the high frequency of the signature by modeling the data to determine the mass.”

While planets are often discovered within the Milky Way using microlensing, the gravitational effect of even small objects can create high magnification leading to a signature that can be modeled and explained in extragalactic galaxies. Until this study, there has been no evidence of planets in other galaxies.

“This is an example of how powerful the techniques of analysis of extragalactic microlensing can be. This galaxy is located 3.8 billion light years away, and there is not the slightest chance of observing these planets directly, not even with the best telescope one can imagine in a science fiction scenario,” said Guerras. “However, we are able to study them, unveil their presence and even have an idea of their masses. This is very cool science.”

For this study, OU researchers used the NASA Chandra X-ray Observatory at the Smithsonian Astrophysical Observatory. The microlensing models were calculated at the OU Supercomputing Center for Education and Research.

How Black Holes Shape The Cosmos

Every galaxy harbours a supermassive black hole at its center. A new computer model now shows how these gravity monsters influence the large-scale structure of our universe. The research team includes scientists from the Heidelberg Institute for Theoretical Studies (HITS), Heidelberg University, the Max-Planck-Institutes for Astronomy (MPIA, Heidelberg) and for Astrophysics (MPA, Garching), US universities Harvard and the Massachusetts Institute of Technology (MIT), as well as the Center for Computational Astrophysics in New York. The project, “Illustris — The Next Generation” (IllustrisTNG), is the most complete simulation of its kind to date. Based on the basic laws of physics, the simulation shows how our cosmos evolved since the Big Bang. Adding to the predecessor Illustris project, IllustrisTNG includes some of the physical processes which play a crucial role in this evolution for the very first time in such an extensive simulation. First results of the IllustrisTNG project have now been published in three articles in the journal Monthly Notices of the Royal Astronomical Society. These findings should help to answer fundamental questions in cosmology.

A realistic universe out of the computer

At its intersection points, the cosmic web of gas and dark matter predicted by IllustrisTNG hosts galaxies quite similar to the shape and size of real galaxies. For the first time, hydrodynamical simulations could directly compute the detailed clustering pattern of galaxies in space. Comparison with observational data — including newest large surveys — demonstrate the high degree of realism of IllustrisTNG. In addition, the simulations predict how the cosmic web changes over time, in particular in relation to the underlying “back bone” of the dark matter cosmos. “It is particularly fascinating that we can accurately predict the influence of supermassive black holes on the distribution of matter out to large scales,” says principal investigator Prof. Volker Springel (HITS, MPA, Heidelberg University). “This is crucial for reliably interpreting forthcoming cosmological measurements.”

The most important transformation in the life cycle of galaxies

In another study, Dr. Dylan Nelson (MPA) was able to demonstrate the important impact of black holes on galaxies. Star-forming galaxies shine brightly in the blue light of their young stars until a sudden evolutionary shift ends the star formation, such that the galaxy becomes dominated by old, red stars, and joins a graveyard full of “red and dead” galaxies. “The only physical entity capable of extinguishing the star formation in our large elliptical galaxies are the supermassive black holes at their centers,” explains Nelson. “The ultrafast outflows of these gravity traps reach velocities up to 10 percent of the speed of light and affect giant stellar systems that are billions of times larger than the comparably small black hole itself.”

Where the stars sparkle: New findings for the structures of galaxies

IllustrisTNG also improves researchers´ understanding of the hierarchical structure formation of galaxies. Theorists argue that small galaxies should form first, and then merge into ever larger objects, driven by the relentless pull of gravity. The numerous galaxy collisions literally tear some galaxies apart and scatter their stars onto wide orbits around the newly created large galaxies, which should give them a faint background glow of stellar light. These predicted pale stellar halos are very difficult to observe due to their low surface brightness, but IllustrisTNG was able to simulate exactly what astronomers should be looking for in their data. “Our predictions can now be systematically checked by observers,” Dr. Annalisa Pillepich (MPIA) points out, who led a further IllustrisTNG study. “This yields a critical test for the theoretical model of hierarchical galaxy formation.”

Astrophysics with a special code and a supercomputer

For the project, the researchers developed a particularly powerful version of their highly parallel moving-mesh code AREPO and used it on the Hazel Hen machine at the High-Performance Computing Center Stuttgart, Germany’s fastest mainframe computer, currently ranked nineteenth in the Top500. IllustrisTNG is the largest hydrodynamic simulation project to date for the emergence of cosmic structures. To compute one of the two main simulation runs, over 24,000 processors were used over the course of more than two months to follow the formation of millions of galaxies in a representative region of the universe with nearly one billion light-years on a side. “Thanks to the computing time obtained from the German Gauss Centre for Supercomputing, we have been able to redefine the state of the art in this field,” explains Volker Springel. “The new simulations produced more than 500 terabytes of simulation data. Analyzing this huge mountain of data will keep us busy for years to come, and it promises many exciting new insights into different astrophysical processes.”

Mayon Ejects 1,000-M Ash Plume

MANILA – Mount Mayon spewed a 1,000-meter ash plume on Friday, as authorities looked for ways to decongest evacuation centers that house tens of thousands.

The volcano has been emitting carbon dioxide and sulfur in “degassing” episodes that may lessen the chances of further eruption, vulcanologists said.

The Office of Civil Defense in Bicol has ordered the decampment of evacuees whose homes are outside the 8-kilometer danger zone to decongest evacuation centers.

The most active volcano in the country has been belching ash and lava since mid-January sending thousands of people to evacuation centers.

The government earlier said it was bracing for a possible 3-month-long emergency in areas around the Mayon Volcano, which displaced more than 81,000.

Distant Galaxy Group Contradicts Common Cosmological Models, Simulations

An international team of astronomers has determined that Centaurus A, a massive elliptical galaxy 13 million light-years from Earth, is accompanied by a number of dwarf satellite galaxies orbiting the main body in a narrow disk. In a paper published today in Science, the researchers note that this is the first time such a galactic arrangement has been observed outside the Local Group, home to the Milky Way.

“The significance of this finding is that it calls into question the validity of certain cosmological models and simulations as explanations for the distribution of host and satellite galaxies in the universe,” said co-author Marcel Pawlowski, a Hubble Fellow in the Department of Physics & Astronomy at the University of California, Irvine.

He said that under the lambda cold dark matter model, smaller systems of stars should be more or less randomly scattered around their anchoring galaxies and should move in all directions. Yet Centaurus A is the third documented example, behind the Milky Way and Andromeda, of a “vast polar structure” in which satellite dwarves co-rotate around a central galactic mass in what Pawlowski calls “preferentially oriented alignment.”

The difficulty of studying the movements of dwarf satellites around their hosts varies according to the target galaxy group. It’s relatively easy for the Milky Way. “You get proper motions,” Pawlowski said. “You take a picture now, wait three years or more, and then take another picture to see how the stars have moved; that gives you the tangential velocity.”

Using this technique, scientists have measurements for 11 Milky Way satellite galaxies, eight of which are orbiting in a tight disk perpendicular to the spiral galaxy’s plane. There are probably other satellites in the system that can’t be seen from Earth because they’re blocked by the Milky Way’s dusty disk.

Andromeda provides observers on Earth a view of the full distribution of satellites around the galaxy’s sprawling spiral. An earlier study found 27 dwarf galaxies, 15 arranged in a narrow plane. And Andromeda offers another advantage, according to Pawlowski: “Because you see the galaxy almost edge-on, you can look at the line-of-sight velocities of its satellites to see the ones that are approaching and those that are receding, so it very clearly presents as a rotating disk.”

Centaurus A is much farther away, and its satellite companions are faint, making it more difficult to accurately measure distances and velocities to determine movements and distributions. But “sleeping in the archives,” Pawlowski said, were data on 16 of Centaurus A’s satellites.

“We could do the same game as with Andromeda, where we look at the line-of-sight velocities,” he said. “And again we see that half of them are red-shifted, meaning they are receding from us, and the other half are blue-shifted, which tells us they are approaching.”

The researchers were able to demonstrate that 14 of the 16 Centaurus A satellite galaxies follow a common motion pattern and rotate along the plane around the main galaxy — contradicting frequently used cosmological models and simulations suggesting that only about 0.5 percent of satellite galaxy systems in the nearby universe should exhibit this pattern.

“So this means that we are missing something,” Pawlowski said. “Either the simulations lack some important ingredient, or the underlying model is wrong. This research may be seen as support for looking into alternative models.”

Popocatépetl Volcano Eruption: Ash Spits Mile Into Sky Covering Town As Area Put On Alert

The 5,462m volcano, just 45 miles from the capital Mexico City, started erupting on Tuesday and agencies have now warned the public to stay at least 7.5miles away.

A column of ash soared roughly 1.24miles into the sky at 4.48pm local time yesterday.

Mexico’s centre for disaster prevention has issued a yellow alert, meaning people need to prepare for a possible evacuation.

The agency has also warned that if heavy rain starts there will be a risk of mudslides and landslides.

Mexico’s Civil Proection said in a statement: “Close doors and windows and seal points of entry with wet rags, do not use contact lenses, avoid the use of vehicles, avoid outdoor activities and protect your eyes, nose and mouth when in the open.”

Low and intermediate activity is expected to continue, and could possibly cause small amounts of ash to fall nearby.

Popocatépetl, which translates to “smoky mountain” in Aztec, is the second highest volcano in North America, and is Mexico’s most active.

The volcano has had more than 15 major eruptions since 1519.

Popocatépetl is considered the most threatening on the continent because it can switch from a low-level eruption to the most powerful type quickly.

These so-called Plinian eruptions are the highest category and tend to be caused by very thick lava that doesn’t flow very easily.

They include pyroclastic flows, a crushing wave of rock, lava, ash and gas, similar to that which buried Pompeii in AD 79.

Popocatépetl hasn’t had a Plinian eruption in more than a thousand years, but it has been erupting on and off since 2005.

Scientists want to better understand how volcanoes like Popocatépetl can switch fro gentler eruptions to more deadly ones.

In October last year thick rivers of mud washed into towns and villages in Mexico from the edge of Popocatépetl as locals feared it would erupt.

Experts at the Sismologia Mundial geological news service reported the plume as a “mild eruption” and confirmed its status as “normal” shortly after.

UPADTE: Rare Super Blue Blood Moon and Earth Movement Events

Yesterday’s early morning super-blue-blood full lunar eclipse occurred. The eclipse was visible mostly in Asia, Australia, the Pacific and North America. The next one visible in North America will occur on Jan. 21, 2019.

The reason for the moon’s reddish color is caused by a process called Rayleigh scattering. The gas molecules of Earth’s atmosphere scatter blue wavelengths of light from the Sun, while red wavelengths pass straight through. This process is also why we have blue skies and red sunrises and sunsets.

 

The cause of what is described as a ‘supermoon’, is due to the full phase taking place at the moon’s closest point in its orbit around the Earth, also called the perigee. Because this moon’s passage is crossing closer to Earth, the gravitational pull causes tide fluctuation as well as fluid displacement. Fluid displacement includes any form of water, oil, and magma.

 

Historically, my published research has identified a 14 day window prior to, and 14 day post period of a full lunar eclipse event. This occurrence certainly fits as witnessed by a series of earthquakes and increased volcanic activity beginning January 23rd after Alaska’s 7.9 earthquake triggering numerous aftershocks, related quakes and volcanic eruptions.

The question now presents itself asking will there be more Earth Changing activity over the next 2 weeks?   Stay Tuned…..