Tag: mdash (page 4 of 19)

Rare Quartet of Quasars Found in the Early Universe


This image shows a rare view of four quasars, indicated by white arrows, found together by astronomers using the Keck Observatory in Hawaii. The bright galactic nuclei are embedded in a giant nebula of cool, dense gas visible in the image as a blue haze. Hennawi & Arrigoni-Battaia, MPIA


Excerpt from smithsonian.com

The odds of success would make a Vegas bookie sit up and take notice. But in a one-in-10 million chance, astronomers surveying the sky have found a group of four tightly packed quasars in one of the most distant parts of the universe. The rare grouping may be a nascent galaxy cluster, and its unusually cold cradle of gas could prompt a re-think of how we model the early universe.

Quasars are among the brightest objects known—according to NASA, each one gives off more energy than 100 mature galaxies combined. But quasars are found only in the far reaches of the universe and can't be seen with the naked eye. Because of the time it takes light to travel that far, detecting such distant objects is akin to seeing back in time, so astronomers think quasars are the seeds of young galaxies, powered by gases falling into the supermassive black holes at their cores. As matter falls inward and gets close to the speed of light, it emits radiation that we can pick up with telescopes.

The quasar phase doesn't last long, only about a thousandth of a galaxy's lifetime. After that, the brightness dies down as the inflow of matter slows, says study leader Joseph Hennawi, an astrophysicist at the Max Planck Institute in Germany. Seeing any two quasars close together while they are still bright is a chancy business, so his team wasn't sure what they'd find when they set out to survey quasars using the W.M. Keck Observatory in Hawaii. To their surprise, they quickly pinpointed four of them in close proximity, cosmically speaking. The quartet is huddled up in an area of sky less than 600,000 light-years across that sits about 10 billion light-years from Earth.

"The authors found it by investigating the environment of just 29 bright quasars," says Michele Trenti, a senior lecturer at the University of Melbourne's School of Physics. "So at face value it seems like winning the lottery with a handful of tickets."
That's not all that was strange about this quasar quartet. The foursome was found inside a cloud of cold, dark gas, and the team's observations suggest that similar clouds surround about 10 percent of the tens of thousands of known quasars. That's odd, because according to current theories, quasars in groups like this should be surrounded by hot plasma, or ionized gas, at a temperature of about 10 million degrees.

“What this means is that there is some physical process that the models aren’t capturing,” says Hennawi, whose team reports the discovery this week in Science.



View Full Article   Read More

12 Signs Your Dog Is Basically Your Furry Child





thedodo.com

1. Snack time is no longer a solo activity ...


2. ... And you always have a little reminder of when it's dinner time.


3. You always have a bed buddy — whether there's room for one or not.


4. The word "messy" is now taken to a whole new level in your household.


5. You have more pictures of your pup than you do of people.


6. Your house is full of toys that do not belong to you.


7. You never need to set an alarm — you'll definitely be woken up in the mornings.


8. You no longer have sole ownership of your possessions ...


9. ... Or your food.


10. You take more pride in their accomplishments than you do your own.


11. You'd do anything to keep them from getting scared.


12. And the most telling sign? Your pup is always the most surefire way to brighten your day.



View Full Article   Read More

New Horizons Spacecraft Captures Image of Pluto & Tiny Moons

An artist's concept shows the moon view of the Pluto system.

Excerpt from cbc.ca



NASA's Pluto-bound spacecraft can now see the dwarf planet's two tiniest known moons — both less than 30 kilometres wide.
Kerberos (which is 10 to 30 kilometres wide) and Styx (which is seven to 21 kilometres) are seen circling Pluto, along with the slightly larger moons Hydra and Nix, in an animated series of "family photos" captured by the New Horizons spacecraft between April 25 and May 1, and released by NASA Tuesday.


Pluto and its four smallest moons can all be seen in this "family photo" captured by the New Horizons spacecraft on April 27.


space animated GIF

"New Horizons is now on the threshold of discovery," said mission science team member John Spencer, from the Southwest Research Institute in Boulder, Colo., in a statement. "If the spacecraft observes any additional moons as we get closer to Pluto, they will be worlds that no one has seen before."

New Horizons is scheduled to make a close flyby of Pluto and its moons on July 14.



At the time the images were taken, the spacecraft was 89 million kilometres away. The glare from Pluto and its largest moon Charon, along with the light of background stars, were damped out using image processing.

Kerberos and Styx were discovered using the Hubble telescope in 2011 and 2012, respectively.

View Full Article   Read More

Archaeologists Believe they have Found the Ruins of a Legendary Monastery



Excerpt from icelandreview.com

It is believed the remains of the much-searched-for Þykkvabær cloister may have been found. Icelandic and British archaeologists saw the remains of a very large building yesterday, using ultrasound techniques, at Álftaver in South Iceland.

The discovery came as a complete surprise, as it was not thought the remains of the cloister were in that area.

“I think we’ve just hit the jackpot, because I think we’ve discovered the remains of Þykkvabæjarklaustur. It came as a complete surprise, you can say that much. The remains are not on the site it was assumed the cloisters stood,” archaeology professor Steinunn Kristjánsdóttir told Stöð 2 television.

Þykkvabæjarklaustur, east of Mýrdalur, was a monastery of Augustine monks and its location has been lost to archaeologists until now. This week, ten Icelandic and British archaeologists have been searching for the remains with high tech instruments. The remains of an unusually big building were discovered under the ground yesterday, measuring around 40 x 45 meters.

“It is very big compared to the buildings of the time – as it is from the Middle Ages – and the footprint is around 1,500 square meters,” Steinunn says.

The cloister was in use from 1168 until 1550. Until recently it was assumed that Þykkvabæjarklaustur must have stood near the present-day Þykkvabæjarkirkja church, but searches revealed nothing; and this leads Steinunn to strongly believe yesterday’s find to be the lost cloisters. It is still possible, however, the remains are of a cow shed—but in that case it would be the cloister’s own cow shed and still therefore relevant.

View Full Article   Read More

Circus Lion Freed From Cage Feels Earth Beneath His Paws For The First Time ~ Heartwrenching Video!




Will

Excerpt from thedodo.com
By Stephen Messenger

Footage shared this week by the Rancho dos Gnomos Santuário in Brazil shows the thrilling moment a lion named Will experiences, for the first time, the feeling of soil and grass beneath his feet.

Prior to being rescued and taken to the sanctuary, Will had been forced to perform with a traveling circus. For 13 long years, the lion had been confined to a cramped cage and denied any semblance of a normal existence. 

Within seconds of his release, Will can be seen eagerly running his paws through the soft soil — tragically, a foreign material for a creature who, up until then, had known only cold metal floors. 

Will's reaction to the grass that covers his sprawling new home is equally ecstatic. Despite his age, advanced for his species, the lion rolls around like a happy cub discovering life's simple pleasures. 

But perhaps the most touching part of Will's transition into his new sanctuary can be seen in this moment of repose, as if most impressed not by the feeling of dirt or grass, but by a newfound sense of peace. 

This scene, filmed in 2006 though released this week to the public, was only the beginning. In 2011, Will passed away of old age, but not before finally learning what it meant to be a lion. 

"He had five years of tranquility before he died. Here he had the opportunity to interact with other lions. He loved to lie in grass and look at the sky," sanctuary founder Marcos Pompeo told The Dodo. "He was a very happy lion."

Watch the video of Will's release in its entirety below:



  Click to zoom

View Full Article   Read More

Astrophysicists Can Now Make Weather Forecasts For Distant Planets


Exoplanet day/night cycle
Cloudy mornings and scorching hot afternoons: the Kepler space telescope has provided weather forecasts for some distant exoplanets.


Excerpt from techtimes.com

A telescope observing distant planets has found evidence of weather patterns, allowing astrophysicists to "forecast" their conditions.

Analyzing data from NASA's Kepler space telescope, a team of astrophysicists at universities in Canada and Great Britain has identified signs of daily weather variations on six exoplanets.
They observed phase variations as different parts of the planets reflected light from their host stars, in much the same way that our moon cycles though different phases.

"We determined the weather on these alien worlds by measuring changes as the planets circle their host stars, and identifying the day-night cycle," said Lisa Esteves from the Department of Astronomy and Astrophysics at the University of Toronto.

"We traced each of them going through a cycle of phases in which different portions of the planet are illuminated by its star, from fully lit to completely dark," added Esteves, who the led the team on the study.

The scientists have offered up "forecasts" of cloudy mornings for four of the planets, and clear but scorching hot afternoons on two others.

They based their predictions on the planets' rotations, which produce an eastward motion of their atmospheric winds. That would blow clouds that formed over the cooler side of one of the planets around to its morning side — thus producing the "cloudy" morning forecast.

"As the winds continue to transport the clouds to the day side, they heat up and dissipate, leaving the afternoon sky cloud-free," said Esteves. "These winds also push the hot air eastward from the meridian, where it is the middle of the day, resulting in higher temperatures in the afternoon."

The Kepler telescope has proven to be the ideal instrument for studying phase variations on distant exoplanets, according to the researchers.

The massive amounts of data and the extremely precise measurements that the telescope is capable of permits them to detect even tiny, subtle signals coming from the distant world, and to separate them from the almost overwhelming light coming from their host stars.

"The detection of light from these planets hundreds to thousands of light years away is on its own remarkable," said co-author Ernst de Mooij from the Astrophysics Research Centre from the School of Mathematics and Physics at Queen's University, Belfast.
"But when we consider that phase cycle variations can be up to 100,000 times fainter than the host star, these detections become truly astonishing."

There may come a day when a weather report for a distant planet is a common and unremarkable event, the researchers added.
"Someday soon we hope to be talking about weather reports for alien worlds not much bigger than Earth, and to be making comparisons with our home planet," said Ray Jayawardhana of York University in England.

This study was published in The Astrophysical Journal.

View Full Article   Read More

US Government Admits Americans Have Been Overdosed on Fluoride

Dr. MercolaThe US government has finally admitted they’ve overdosed Americans on fluoride and, for first time since 1962, are lowering its recommended level of fluoride in drinking water.1,2,3About 40 percent of American teens have dental fluorosis,4 a condition referring to changes in the appearance of tooth enamel—from chalky-looking lines and splotches to dark staining and pitting—caused by long-term ingestion of fluoride during the time teeth are forming.In some areas, fluoro [...]

View Full Article   Read More

Hubble Finds Giant Halo Around the Andromeda Galaxy





 Excerpt from hubblesite.org

Scientists using NASA's Hubble Space Telescope have discovered that the immense halo of gas enveloping the Andromeda galaxy, our nearest massive galactic neighbor, is about six times larger and 1,000 times more massive than previously measured. The dark, nearly invisible halo stretches about a million light-years from its host galaxy, halfway to our own Milky Way galaxy. This finding promises to tell astronomers more about the evolution and structure of majestic giant spirals, one of the most common types of galaxies in the universe.

"Halos are the gaseous atmospheres of galaxies. The properties of these gaseous halos control the rate at which stars form in galaxies according to models of galaxy formation," explained the lead investigator, Nicolas Lehner of the University of Notre Dame, Indiana. The gargantuan halo is estimated to contain half the mass of the stars in the Andromeda galaxy itself, in the form of a hot, diffuse gas. If it could be viewed with the naked eye, the halo would be 100 times the diameter of the full Moon in the sky. This is equivalent to the patch of sky covered by two basketballs held at arm's length.

The Andromeda galaxy, also known as M31, lies 2.5 million light-years away and looks like a faint spindle, about 6 times the diameter of the full Moon. It is considered a near-twin to the Milky Way galaxy.

Because the gas in Andromeda's halo is dark, the team looked at bright background objects through the gas and observed how the light changed. This is a bit like looking at a glowing light at the bottom of a pool at night. The ideal background "lights" for such a study are quasars, which are very distant bright cores of active galaxies powered by black holes. The team used 18 quasars residing far behind Andromeda to probe how material is distributed well beyond the visible disk of the galaxy. Their findings were published in the May 10, 2015, edition of The Astrophysical Journal.

Earlier research from Hubble's Cosmic Origins Spectrograph (COS)-Halos program studied 44 distant galaxies and found halos like Andromeda's, but never before has such a massive halo been seen in a neighboring galaxy. Because the previously studied galaxies were much farther away, they appeared much smaller on the sky. Only one quasar could be detected behind each faraway galaxy, providing only one light anchor point to map their halo size and structure. With its close proximity to Earth and its correspondingly large footprint on the sky, Andromeda provides a far more extensive sampling of a lot of background quasars.
"As the light from the quasars travels toward Hubble, the halo's gas will absorb some of that light and make the quasar appear a little darker in just a very small wavelength range," explains co-investigator J. Christopher Howk, also of Notre Dame. "By measuring the dip in brightness in that range, we can tell how much halo gas from M31 there is between us and that quasar."

The scientists used Hubble's unique capability to study the ultraviolet light from the quasars. Ultraviolet light is absorbed by Earth's atmosphere, which makes it difficult to observe with a ground-based telescope. The team drew from about 5 years' worth of observations stored in the Hubble data archive to conduct this research. Many previous Hubble campaigns have used quasars to study gas much farther away than — but in the general direction of — Andromeda, so a treasure trove of data already existed.

But where did the giant halo come from? Large-scale simulations of galaxies suggest that the halo formed at the same time as the rest of Andromeda. The team also determined that it is enriched in elements much heavier than hydrogen and helium, and the only way to get these heavy elements is from exploding stars called supernovae. The supernovae erupt in Andromeda's star-filled disk and violently blow these heavier elements far out into space. Over Andromeda's lifetime, nearly half of all the heavy elements made by its stars have been expelled far beyond the galaxy's 200,000-light-year-diameter stellar disk.

What does this mean for our own galaxy? Because we live inside the Milky Way, scientists cannot determine whether or not such an equally massive and extended halo exists around our galaxy. It's a case of not being able to see the forest for the trees. If the Milky Way does possess a similarly huge halo, the two galaxies' halos may be nearly touching already and quiescently merging long before the two massive galaxies collide. Hubble observations indicate that the Andromeda and Milky Way galaxies will merge to form a giant elliptical galaxy beginning about 4 billion years from now.

View Full Article   Read More

Older posts Newer posts

Creative Commons License
This work is licensed under a
Creative Commons Attribution 4.0
International License
.
unless otherwise marked.

Terms of Use | Privacy Policy



Up ↑