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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.

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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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Amateur N.S. astronomer captures magic of the green comet – CBC.ca

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Nova Scotia·Audio

Tim Doucette with the Deep Sky Eye Observatory in southwestern Nova Scotia has captured a dazzling time-lapse of the green comet that’s making a rare pass near Earth.

Comet C/2022 E3 (ZTF) making its closest approach to Earth on Wednesday

Tim Doucette captured a two-hour time-lapse of the green comet over the weekend. (Tim Doucette/Deep Sky Eye Observatory)

An amateur astronomer from southwestern Nova Scotia has captured a dazzling time-lapse of the green comet that’s making a rare pass near Earth.

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The last time the comet was this close to our planet was 50,000 years ago. Many Canadians are looking up at the stars this week as the comet gets ready to make its closest approach on Wednesday.

Tim Doucette with the Deep Sky Eye Observatory near Yarmouth, N.S., is among them.

He took a two-hour time-lapse of the comet during the early-morning hours of Jan. 28.

“If you’ve got a telescope and you look closely at the comet and the background stars, it’s travelling relative in our sky about one-quarter degrees per hour,” he told CBC Radio’s Mainstreet Halifax. “So within a few minutes you can see that the comet’s actually making motion in the night sky.”

You can listen to Doucette’s full interview with host Jeff Douglas here:

Mainstreet NS8:09Astronomer Tim Doucette captures images of rare green comet

A rare green comet that orbits our sun once every 50,000 years is now in our neighbourhood, and already an amateur astronomer has captured dazzling imagery of it.

Amateur N.S. astronomer captures magic of the green comet

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Tim Doucette with the Deep Sky Eye Observatory in southwestern Nova Scotia has captured a dazzling time-lapse of the green comet that’s making a rare pass near Earth.

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With files from CBC Radio’s Mainstreet Halifax

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Kemptville author’s book being sent to the moon

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One of Michael Blouin’s books is going to be launched into space on a microdisk and stay on the surface of the moon. (Submitted by Michael Blouin)

An author from North Grenville, Ont., is going to be part of a small club of authors whose works will be sent to the moon.

Michael Blouin of Kemptville says he’s been interested in space travel since the Apollo 11 mission that landed humans on the moon for the first time.

To be part of a group of hundreds of authors having their work immortalized within the vast expanse of space has him “gobsmacked.”

“I take comfort in the fact that no matter what happens, it looks like my books … will survive and be there,” he said.

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“I sometimes wake up at night and say ‘Oh yeah, I’m going to the moon. Wow.’ It’s kind of amazing.”

How it came to be

Blouin said he’s been a lifelong fan of NASA and space exploration, so when the opportunity to get his work in the Writers on the Moon project came up, he had to take it.

Then around the deadline to apply, his house burned down.

Amid the chaos of not having anywhere to live and then moving into his son’s house, he realized he’d missed his chance.

“I had missed the deadline to apply for this program for books to go to the moon by 12 hours and I was just kicking myself,” he said.

“I lost everything and now I’d missed out on my chance to do something I’d always dreamed about doing.”

Luckily a friend and author in Newfoundland, Carolyn R. Parsons, said she had managed to get some of her work included in the project and had enough space on her microdisk to include him as well.

A rocket sits upright.
This rocket will carry a lander and books from a couple hundred authors up to the moon. (United Launch Alliance)

When do the books go?

The NASA launch is scheduled for Feb. 25 at Cape Canaveral in Florida, which will see his book Skin House brought to the stars along with other works of independent fiction.

Blouin is getting the chance to see the launch.

“These launches sometimes get delayed due to technical reasons or due to weather,” he said.

“But I’m hoping to give myself a big enough window that I’ll actually be on site.”

Blouin had some advice for people who aspire to write or create.

“Any young person aspiring in the arts just shouldn’t give up. Keep trying,” he said. “It can be a tough go but it’s worth every moment.”

He’s getting another of his books — I am Billy the Kid — up to the moon in 2024.

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Green comet zooming our way, last visited 50,000 years ago – Cochrane Today

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CAPE CANAVERAL, Fla. (AP) — A comet is streaking back our way after 50,000 years.

The dirty snowball last visited during Neanderthal times, according to NASA. It will come within 26 million miles (42 million kilometers) of Earth Wednesday before speeding away again, unlikely to return for millions of years.

So do look up, contrary to the title of the killer-comet movie “Don’t Look Up.”

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Discovered less than a year ago, this harmless green comet already is visible in the northern night sky with binoculars and small telescopes, and possibly the naked eye in the darkest corners of the Northern Hemisphere. It’s expected to brighten as it draws closer and rises higher over the horizon through the end of January, best seen in the predawn hours. By Feb. 10, it will be near Mars, a good landmark.

Skygazers in the Southern Hemisphere will have to wait until next month for a glimpse.

While plenty of comets have graced the sky over the past year, “this one seems probably a little bit bigger and therefore a little bit brighter and it’s coming a little bit closer to the Earth’s orbit,” said NASA’s comet and asteroid-tracking guru, Paul Chodas.

Green from all the carbon in the gas cloud, or coma, surrounding the nucleus, this long-period comet was discovered last March by astronomers using the Zwicky Transient Facility, a wide field camera at Caltech’s Palomar Observatory. That explains its official, cumbersome name: comet C/2022 E3 (ZTF).

On Wednesday, it will hurtle between the orbits of Earth and Mars at a relative speed of 128,500 mph (207,000 kilometers). Its nucleus is thought to be about a mile (1.6 kilometers) across, with its tails extending millions of miles (kilometers).

The comet isn’t expected to be nearly as bright as Neowise in 2020, or Hale-Bopp and Hyakutake in the mid to late 1990s.

But “it will be bright by virtue of its close Earth passage … which allows scientists to do more experiments and the public to be able to see a beautiful comet,” University of Hawaii astronomer Karen Meech said in an email.

Scientists are confident in their orbital calculations putting the comet’s last swing through the solar system’s planetary neighborhood at 50,000 years ago. But they don’t know how close it came to Earth or whether it was even visible to the Neanderthals, said Chodas, director of the Center for Near Earth Object Studies at NASA’s Jet Propulsion Laboratory in California.

When it returns, though, is tougher to judge.

Every time the comet skirts the sun and planets, their gravitational tugs alter the iceball’s path ever so slightly, leading to major course changes over time. Another wild card: jets of dust and gas streaming off the comet as it heats up near the sun.

“We don’t really know exactly how much they are pushing this comet around,” Chodas said.

The comet — a time capsule from the emerging solar system 4.5 billion years ago — came from what’s known as the Oort Cloud well beyond Pluto. This deep-freeze haven for comets is believed to stretch more than one-quarter of the way to the next star.

While comet ZTF originated in our solar system, we can’t be sure it will stay there, Chodas said. If it gets booted out of the solar system, it will never return, he added.

Don’t fret if you miss it.

“In the comet business, you just wait for the next one because there are dozens of these,” Chodas said. “And the next one might be bigger, might be brighter, might be closer.”

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

Marcia Dunn, The Associated Press

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