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Hubble Finds a Bunch of Galaxies That Webb Should Check out – Universe Today

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The Universe is full of massive galaxies like ours, but astronomers don’t fully understand how they grew and evolved. They know that the first galaxies formed at least as early as 670 million years after the Big Bang. They know that mergers play a role in the growth of galaxies. Astronomers also know that supermassive black holes are involved in the growth of galaxies, but they don’t know precisely how.

A new Hubble survey of galaxies should help astronomers figure some of this out.

The survey is called 3D-Drift And SHift (3D-DASH.) 3D-DASH is a high-resolution near-infrared imaging and spectrometry survey of the sky that maps star-forming regions. It’s the largest of its kind. The goal is to find rare galactic objects that the James Webb Space Telescope can target in follow-up observations.

A paper titled “3D-DASH: The Widest Near-Infrared Hubble Space Telescope Survey” presents the new mosaic. It’ll be published in The Astrophysical Journal and is currently available at the pre-press site arxiv.org. The lead author is Lamiya Mowla, Dunlap Fellow at the Faculty of Arts & Science’s Dunlap Institute for Astronomy & Astrophysics at the University of Toronto.

Since its launch more than 30 years ago, the Hubble Space Telescope has led a renaissance in the study of how galaxies have changed in the last 10-billion years of the Universe,” said the lead author Mowla. “The 3D-DASH program extends Hubble’s legacy in wide-area imaging so we can begin to unravel the mysteries of the galaxies beyond our own.”

3D-DASH is an improvement on an earlier effort called COSMOS. COSMOS covered a 2 square degree equatorial field using multiple space-based and ground-based telescopes, using spectroscopy, x-ray, and radio imaging. It contains over 2 million galaxies that span 75% of the age of the Universe.

This image shows the patch of sky covered by COSMOS, the predecessor to 3D-DASH. 3D-DASH will cover the same chunk of the sky but will add near-infrared observations. Image Credit: COSMOS/Caltech.
This image shows the patch of sky covered by COSMOS, the predecessor to 3D-DASH. 3D-DASH will cover the same chunk of the sky but add near-infrared observations. Image Credit: COSMOS/Caltech.

3D-DASH improves on COSMOS by surveying its entire contents in near-infrared. That’s significant because it allows astronomers to see the most distant, earliest galaxies.

Survey size is critical in the study of galaxies. To be productive, surveys have to identify unique phenomena in the Universe: the most massive galaxies, the oldest galaxies, and galaxies on the verge of merging are critical to expanding our understanding of galaxies. So are highly active black holes. But to find those, astronomers need huge images that they can comb through.

This is the 3D-DASH mosaic. The zoomed-in panels reveal the wealth of bright objects that can be studied in this high-resolution shallow tier of the extragalactic wedding cake. Image Credit: Mowla et al. 2022.
This is the 3D-DASH mosaic. The zoomed-in panels reveal the wealth of bright objects that astronomers can study in this high-resolution shallow tier of the extragalactic wedding cake. Image Credit: Mowla et al. 2022.

Previous surveys weren’t as robust because they were ground-based. They suffered from low resolution, limiting what astronomers could learn from them. 3D-DASH doesn’t suffer from those same limitations.

I am curious about giant galaxies, which are the most massive ones in the Universe formed by the mergers of other galaxies. How did their structures grow, and what drove the changes in their form?” says Mowla, who began work on the project in 2015 while a grad student at Yale University. “It was difficult to study these extremely rare events using existing images, which is what motivated the design of this large survey.

3D-DASH allowed astronomers to create a census of rare close pairs of galaxies. They're critical for studying the evolution of galaxy merger rates. These galaxy pairs are separated by less than 20 kiloparsecs. Image Credit: Mowla et al. 2022.
3D-DASH allowed astronomers to create a census of rare close pairs of galaxies. They’re critical for studying the evolution of galaxy merger rates. These galaxy pairs are separated by less than 20 kiloparsecs. Image Credit: Mowla et al. 2022.

DASH stands for Drift And SHift, the name of the new imaging technique that Mowla and her colleagues. DASH is similar to taking a panoramic image with a smartphone. The method captures multiple images that are then stitched together into one enormous image. DASH is a huge time-saver and took images in 250 hours that previously would’ve taken 2000 hours.

It does this by capturing eight images per Hubble orbit rather than one. Only the first of each of the eight images is pointed, and the following seven are unguided and taken while the Hubble “drifts and shifts.” The technique means that the data reduction procedures are more demanding, but the result is worth it.

3D-DASH adds a new layer of unique observations in the COSMOS field and is also a steppingstone to the space surveys of the next decade,” says Ivelina Momcheva, head of data science at the Max Planck Institute for Astronomy and principal investigator of the study. “It gives us a sneak peek of future scientific discoveries and allows us to develop new techniques to analyze these large datasets.

3D-DASH also allowed astronomers to create a census of the most active star-forming regions of the rare massive star-forming galaxies in the last 5 Gyrs. Each of these images is 40 kiloparsecs square. Image Credit: Mowla et al. 2022.
3D-DASH also allowed astronomers to create a census of the most active star-forming regions of the rare massive star-forming galaxies in the last 5 Gyrs. Each of these images is 40 kiloparsecs square. Image Credit: Mowla et al. 2022.

3D-DASH provides a list of galactic targets for the James Webb Space Telescope, which should start science observations soon. The ‘Early Universe‘ and ‘Galaxies Over Time‘ are two of the JWST’s overarching science objectives. “Webb’s unprecedented infrared sensitivity will help astronomers to compare the faintest, earliest galaxies to today’s grand spirals and ellipticals, helping us to understand how galaxies assemble over billions of years,” NASA writes. The list of targets from 3D-DASH will help advance those objectives.

You can explore an online version of the mosaic here.

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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