Sunday April 21, 2019
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Study Reveals Shape and Structure of The Milky Way Galaxy

So our Milky Way's twists are rare but not unique, they said

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Saraswati
Earth is part of the Milky way galaxy. Wikimedia

The Milky Way’s disk of stars is not stable or flat but instead becomes increasingly “warped” and twisted far away from the galaxy’s centre, according to astronomers.

“We usually think of spiral galaxies as being quite flat, like Andromeda which you can easily see through a telescope,” said Professor Richard de Grijs from Macquarie University in Australia.

To understand, the team used 1,339 “standard” stars, each up to 100,000 brighter than our sun, to map the real shape of our home galaxy.

The new 3D map of our galaxy showed that the warped Milky Way disc also contains young stars and confirmed that the warped spiral pattern is caused by torque from the spinning of the Milky Way’s massive inner disc of stars, accordoing to the study published in the Nature Astronomy journal.

From a great distance, our galaxy would look like a thin disk of stars that orbit once every few hundred million years around its central region, where hundreds of billions of stars, together with a huge mass of dark matter, provide the gravitational “glue” to hold it all together.

Representational Image of Milky Way.
Image Source: Wikimedia Commons.

But the pull of gravity becomes weaker far away from the Milky Way’s inner regions. In the galaxy’s far outer disk, the hydrogen atoms making up most of the Milky Way’s gas disk are no longer confined to a thin plane, but they give the disk an S-like warped appearance.”It is notoriously difficult to determine distances from the Sun to parts of the Milky Way’s outer gas disc without having a clear idea of what that disc actually looks like,” said Xiaodian Chen from the Chinese Academy of Sciences in Beijing.

“This research provides a crucial updated map for studies of our galaxy’s stellar motions and the origins of the Milky Way’s disk,” added Licai Deng, also from the Chinese Academy of Sciences.

Also Read- 2018 Fourth-hottest Year Since 1880; Earth Set to Get Warmer, Says NASA

Astronomers have observed a dozen other galaxies which showed similar progressively twisted spiral patterns in their outer regions.

So our Milky Way’s twists are rare but not unique, they said.  (IANS)

Next Story

Major Achievement! Scientists Take The First-Ever Image of Black Hole

At the press conference, researchers told the story about how it was much quicker to take the data by plane to the various supercomputers being used to analyze the information.

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Black Hole
An image of the black hole at the center of Messier 87, a massive galaxy in the nearby Virgo galaxy cluster. This black hole resides 55 million light-years from Earth and has a mass 6.5-billion times that of the sun. VOA

Using eight radio telescopes literally spanning the globe, scientists have taken the first-ever photograph of a black hole.

The supermassive black hole is at the center of a huge galaxy called M-87, which is 55 million light-years from Earth.

The picture, the result of decades of work by the Event Horizon Telescope Collaboration (EHTC), isn’t much to look at. It’s a fuzzy orange and yellow donut floating in space, but the implications for physics, and the incredibly intricate way that researchers got the picture, is science at its best.

The picture is exactly what scientists, particularly the late Albert Einstein, predicted it would look like. There is the eponymous center black hole where gravity is so powerful even light cannot escape, and a circular area of superheated energy rotating around the celestial entity at nearly the speed of light, called the event horizon.

“We now know that a black hole that weighs 6.5 billion times what our sun does exists in the center of M-87,” EHTC scientist Shep Doeleman announced at a press conference Wednesday in Washington. “And this is the strongest evidence that we have to date for the existence of black holes.”

This picture is so important because while scientists have been seeing the effects that black holes have on the structures around them, they have never actually seen one, and this photo in effect proves their existence, as well as one of the foundational principles of Einstein’s theory of general relativity.

200 scientists

At its center, the black hole is so big that even though it’s a long distance away, scientists reasoned it was likely to be the largest such structures viewable from Earth. For that reason, M-87 was chosen for the experiment.

More than 200 scientists worked for about a decade to link the global network of eight radio telescopes, using atomic clocks. One by one in an exact sequence, the instruments were pointed at M-87 at what was, in effect, the same time, back in April 2017.

When the experiment was over, the researchers had five petabytes — or a million gigabytes — of visual information to review. At the press conference, researchers told the story about how it was much quicker to take the data by plane to the various supercomputers being used to analyze the information. They said this was easier than trying to transfer that much data into the cloud.

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The supermassive black hole is at the center of a huge galaxy called M-87, which is 55 million light-years from Earth.Pixabay

It took two weeks for a group of supercomputers to analyze the data and begin to form all the collected information into the modest photo that scientists released Wednesday.

Also Read: Chinese Researchers Reveal Mechanism of Chronic Stress Promoting Breast Cancer Development

And once that photo was collected, the researchers waited two years to publish their data while scientists from all over the world checked their work and signed off on the idea that what was photographed was actually a black hole.

What happens now?

The team isn’t done, though. They already are planning to create even bigger telescopes than the Earth-sized one they used by incorporating space telescopes like the Hubble and the soon-to-be-launched James Webb Space Telescope. This should allow researchers to take photos of dozens of other black holes. (VOA)