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Nova Scotia professor studies light at the edge of supermassive black holes – NiagaraFallsReview.ca

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HALIFAX – Black holes, the astronomical mysteries at the centre of physics and astronomy, aren’t the cosmic vacuums people think they are.

Their activity is a lot more complicated than that, says Luigi Gallo, professor in the astronomy and physics department at Saint Mary’s University in Halifax.

“A lot of black holes actually eject a lot of material out into space,” Gallo said in an interview Tuesday.

“This material can then get shot across the galaxy, even into the space between galaxies, and it can kind of affect how galaxies form and how the galaxy evolves sometimes.”

Gallo’s research focuses on supermassive black holes — the regions in space where gravity is so strong that not even light can escape. Supermassive black holes are orders of magnitude larger than our sun.

He and his students are looking into the area right at the edge of supermassive black holes as well as the high-temperature X-rays that are found there. Beyond that edge — known as the event horizon — scientists aren’t able to see what’s going on because light gets sucked into the black hole’s maw and disappears.

Gallo said by looking at the edges of supermassive black holes — the largest kinds of black holes — he and other scientists are hoping to get a better picture of the shape of the area surrounding the perimeter of those massive voids. They want to know what that area is made of and how it’s falling into the hole.

X-rays, Gallo said, are made of light the human eye can’t see. And therefore, he said, to study them, scientists are planning to launch a new satellite into space. His research is being used in the development of the satellite, called XRISM. The project is backed by NASA and the Japan Aerospace Exploration Agency, and it is set to be launched into space in 2022.

The satellite will be equipped with a tool called a calorimeter, which is a sensitive prism that will break the X-rays into a band of colours. From there, researchers will be able to use the different colours to identify the composition of the material and its movement around a black hole, giving them more information about the “geometry” of the region just outside the hole itself, Gallo said.

There is an exchange between the black hole and the outer reaches of the galaxy it’s located in, Gallo said, a sort of “feedback” loop that allows the two to “know” about each other. “We understand that there’s a relationship between how galaxies grow and how black holes at the centre grow, but we don’t really know exactly which one is driving which.”

He said that as the black hole becomes “active” and spits material out into space, “it can trigger or turn off star formations,” affecting how heavenly bodies in the path of the material evolve. Scientists believe these massive objects exist at the centre of every galaxy.

Though scientists aren’t exactly sure how the relationship between a galaxy’s dark centre and its outermost reaches works, Gallo said the new satellite can hopefully help explain.

“The galaxy dumps material onto the black hole and then at some point the black hole says, ‘That’s enough material, I don’t want any more,’ and it tosses it back out into the galaxy and it turns things off and stops the feeding process,” he said.

“Eventually it stops tossing material out and the galaxy starts feeding it again and you get this cyclic process.”

This report by The Canadian Press was first published Jan. 13, 2021.

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This story was produced with the financial assistance of the Facebook and Canadian Press News Fellowship.

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NASA Curiosity rover celebrates 3000th day on Mars with stunning panorama of planet – Barrie 360 – Barrie 360

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Sophie Lewis – CBS News

NASA’s Curiosity rover just celebrated a major milestone — 3,000 days on the surface of Mars. To mark the occasion, the space agency has released a stunning new panorama of the red planet, captured by the rover. 

Curiosity landed on Mars on August 6, 2012. However, scientists track its activities in Martian days, called “sols,” which are a bit longer than Earth days, at 24 hours and 39 minutes. 

The epic new panorama, released by the space agency on Tuesday, captures the view of the 96-mile-wide Gale Crater and part of Mount Sharp, its central mountain. It was taken by Curiosity’s eyes, AKA the Mast Camera. 

This panorama, made up of 122 individual images stitched together, was taken by NASA’s Curiosity Mars rover on November 18, 2020, the 2,946th Martian day, or sol, of the mission. NASA/JPL-CALTECH/MSSS

Curiosity has been gradually climbing and exploring the 3-mile-tall Mount Sharp since 2014. Its most recent find, captured in the panorama, is a series of distinctive “bench-like rock formations,” which can form due to erosion, as well as landslides. 

The mountain’s rock layers were shaped by bodies of water billions of years ago. “Curiosity’s team has seen benches before in Gale Crater, but rarely forming such a scenic grouping of steps,” NASA said.  

“Our science team is excited to figure out how they formed and what they mean for the ancient environment within Gale,” said Curiosity’s project scientist, Ashwin Vasavada of NASA’s Jet Propulsion Laboratory. 

The panorama is actually a composite of 122 images taken by Curiosity on November 18. After it was taken, the rover continued to higher ground, working its way toward the next major layer, called the “sulfate-bearing unit.” 

Since its mission began, Curiosity has been in search of conditions that may have once supported life, gathering rock samples along the way to analyze.

It’s had a number of major accomplishments, including finding evidence the planet once had persistent liquid water, discovering that the planet was once suitable for life and finding organic carbon molecules, the building blocks of life. It also found present and active methane in the red planet’s atmosphere, detected radiation levels that could post health risks to humans, and concluded that Mars’ atmosphere used to be much thicker than it is today. 

Curiosity will soon be joined by its sibling rover, Perseverance, when it lands on the red planet in February. Perseverance is designed to bring samples from Mars back to Earth, marking the first round-trip mission to another planet.

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In Photos: Hubble Captures Echoes Of Violent Supernova ‘Fireworks’ That Lit-Up Night Sky In The Third Century – Forbes

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The Hubble Space Telescope has captured light from a supernova blast—an exploding star—that would have been seen from Earth 1,700 years ago.

Although there are no known records of anyone seeing it, a cosmic explosion that’s been compared to fireworks would have been visible to people in Earth’s southern hemisphere.

It’s now visible to the Hubble Space telescope as a delicate greenish-blue shell—a supernova remnant (SNR)—in a nearby galaxy to the Milky Way called the Small Magellanic Cloud (SMC).

The SNR is called 1E0102.2-7219, or E0102 for short. Here’s everything you need to know about how Hubble’s spectacular images have been used to precisely date an incredible supernova explosion.

What and where is E0102?

E0102 is the leftovers of a massive explosion of a star in a nearby dwarf galaxy—the SMC.

The images from Hubble show the aftermath of a supernova—the dissipating energy has created a spectacular display of greenish-blue filaments.

The above image of part of the SMC shows that E0102 is “close”—about 50 light-years—from a massive star-forming region of glowing hydrogen emission called N 76 and Henize. You can see that as the pink-ish section in the upper-right of the image. E0102 is at the center of the image.

What do we know about the star?

Not much, though it may have been a Wolf-Rayet star—a very large and old star made from heavy elements that had probably blown-off its hydrogen before the explosion.

Astronomers think that because the colors of E0102 indicate that it was rich in oxygen rather than hydrogen and helium.

How did astronomers use Hubble’s images?

Although E0102 was previously known about, its age was unknown. Treating E0102 as forensic evidence, astronomers used Hubble’s observations of E0102 taken a decade apart to calculate the cloud’s expansion rate.

They did that by calculating how fast 22 separate oxygen-rich knots of debris in the SNR had moved in 10 years. They then traced it back to the point in space where the progenitor star must have exploded.

Why Hubble’s longevity was so crucial

“A prior study compared images taken years apart with two different cameras on Hubble, the Wide Field Planetary Camera 2 and the Advanced Camera for Surveys (ACS),” said Danny Milisavljevic of Purdue University in West Lafayette, Indiana, one of the leaders of the research team whose paper was presented yesterday at the 237th meeting of the American Astronomical Society.

“But our study compares data taken with the same camera, the ACS, making the comparison much more robust; the knots were much easier to track using the same instrument,” he said.

“It’s a testament to the longevity of Hubble that we could do such a clean comparison of images taken 10 years apart.”

What is the SMC?

The Small Magellanic Cloud is a satellite galaxy of our Milky Way. It’s about 200,000 light-years away in the constellation Tucana. It’s really easy to see in the night skies in the southern hemisphere.

Wishing you clear skies and wide eyes.

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Creation by catastrophe – Skywatching – Castanet.net

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Collision of the Galaxies sounds like a good title for a spectacular disaster movie.

Actually, a lot of things in the universe depend on things smashing together, including galaxies. The object
Arp 299 is two galaxies in collision.

The two, designated NGC 3690 and IC 694, lying about 134 million light years away from us, have been in the process of collision for around 700 million years. The Hubble Space Telescope image can be found at https://en.wikipedia.org/wiki/Arp_299. The image is dotted with many bright, blue stars.

This is interesting because there are only two types of bright, blue star. One kind are young stars that will dim down a bit as they settle down.

The other kind are stars that collected an exceptionally large amount of hydrogen when they formed. These stars shine extremely brightly, run out of fuel soon, collapse and then explode. These explosions are called supernovae.

In either case, these blue stars cannot be very old. This relates to another interesting aspect of this pair of galaxies: the oddly large number of supernova explosions. What has produced these unusual circumstances?

If you look at a nearby spiral galaxy, such as our close neighbour, the Andromeda Galaxy, you will see the spiral arms glowing with little knots of pink, and sparkling with young stars.

If we could go a couple of million light years off into space, our galaxy, the Milky Way, would look much the same. The reason is that the spiral arms of galaxies are loaded with hydrogen gas, the primary ingredient for making stars.

If we look closer, we will see that these clouds are not uniform; some regions are much denser than others. On occasion, something triggers one of these denser regions to collapse, forming one or more stars.

These youngsters are hot and blue, and their high output of ultraviolet radiation makes the surrounding clouds glow pink. This pink, a characteristic of hydrogen, is known as hydrogen-alpha emission.

Therefore, when we look at a distant galaxy, those pink glows mean two things:

  • There is hydrogen to glow
  • Hot, blue stars to make it glow.

However, the jewel-box of bright, blue stars we see in the Arp 299 pair of galaxies is really unusual. Some major event caused massive collapses of hydrogen clouds, forming showers of new stars. We are pretty sure this outburst of star formation was caused by the two galaxies colliding.

Paradoxically, collisions between galaxies are not totally catastrophic; they trigger the formation of new stars and planets.

When we look at the computer simulations of collisions between galaxies (there are many on the web), they look pretty catastrophic. One can imagine stars and planets being annihilated on a huge scale.

The youtube on this link is a good example of what we believe a collision between two galaxies would look like. However, the situation is nothing like as bad as it looks.

The nearest star to us, after the Sun, lies about four light years away. This distance is fairly typical of the average distance between stars. So the chance of stars in two colliding galaxies passing close to one another is tiny. Even as fragments fly around and the galaxies combine, all the inhabitants of worlds in those galaxies will see is their equivalent of the Milky Way changing shape over millions of years.

However, for the gas clouds between the stars it’s a different matter. These will collide and collapse, forming lots of new stars.

We will get a chance to experience this first hand. The Milky Way and the Andromeda Galaxy are racing toward each other at 110 km/s, and will collide in about four billion years. There are computer simulations of this collision on the web.

  • The only easily visible planet is Mars, which can be found high in the southwest during the evening.
  • The Moon will reach First Quarter on the 20th.

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