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The James Webb Space Telescope data is a treasure trove of material: what are we hoping to find?

Dust, disks, clusters and zodiacal light all on the wishlist.

Images from NIRCam (James Webb Space Telescope’s Near Infrared Camera) have flooded news and social feeds this week, showcasing a stunning deep field of galaxies upon yet more galaxies as the telescope peers further into the universe – and back into time.

Along with the blockbuster pictures, JWST (affectionately known as ‘Webb’) is providing researchers with vast swathes of data. And several Australian research groups are already eagerly sifting through it, peering through the dust in search of new insight into enigmatic galaxies, the early universe and clues to the birth of our solar system.

Contributing to a research project known as GLASS (Grism Lens-Amplified Survey from Space), University of Melbourne postdoctoral researcher Nicha Leethochawalit is using images from Webb’s NIRCam instrument to probe deep into the early universe, looking for objects at times when the universe was still very young. The objects in these images have never been seen before, and Leethochawalit is excited at the prospect of potentially finding totally new kinds of objects, so far unknown or not understood by astrophysicists. GLASS, will also use two other instruments aboard Webb, NIRISS (Near-Infrared Imager and Slitless Spectrograph) and NIRSpec (Near Infrared Spectrograph) to investigate extremely distant galaxy clusters.

NIRSpec is a particularly impressive feat of engineering, able to take spectra (which is essentially a way of looking at the amount of different energies of light) of a huge number of targets at once through the use of microshutters. As Nora Lutzgendorf, NIRSpec Instrument Scientist at ESA/STSci explains, NIRSpec consists of “a quarter of a million teeny little doors that we can individually open and close within a 3×3 arcminute field of view”. (The full Moon’s diameter is about 31 arcminutes on the sky). Typically, telescopes have only one opening with which they view a target. In comparison, each one of these microshutters on Webb could potentially be looking at an individual astronomical object – so that’s a lot of individual things to see all at once.

As part of a number of research projects led by Professor Karl Glazebrook at Swinburne University, Melbourne, postdoctoral researcher Themiya Nanayakkara is using data from these microshutters on NIRSpec to study large, dead galaxies at a time when the universe was between approximately 1.5 and 2 billion years old. These galaxies are considered ‘dead’ because star formation has effectively ceased, and researchers are keen to understand more about their evolution and their dynamics, wanting to understand how the galaxies got to this ‘dead’ point, if they can or will ever come back to life and also how interactions with other galaxies might affect them? Using the microshutters on NIRSpec, Nanayakkara hopes to see 80–100 galaxies in each NIRSpec dataset in astonishingly rich detail.

Although Webb’s ability to probe detail through the dust that normally obscures distant galaxies is a key part of Nanayakkara’s research, he also wants to understand and characterise that dust. Many of the normal processes that create dust in the universe, such as supernovae and Asymptotic Giant Branch stars (which throw off lots of material as they fuse helium in their cores), haven’t really had enough time to evolve to produce the large amounts of dust that we are seeing in the earliest times of the universe.

As Nanayakkara quips: “Dust is basically, us right? So, we want to know what’s made this dust and what happens to it over time.”

In another project, University of Queensland extrasolar planets expert Benjamin Pope is investigating the formation and evolution of protoplanetary disks around several stars in the Milky Way using the NIRISS instrument. These dusty disks of debris are thought to be the birthing grounds of planets, which coalesce and grow under the influence of gravity.

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Using a custom-built “aperture masking instrument” – the brainchild of Professor Peter Tuthill from the University of Sydney (according to Pope, “the only public Australian institution contributing hardware for the JWST”) – Pope is looking at extrasolar transition disks: “where there are gaps in the disc by actively forming planets”, he explains.

This means it’s like watching the construction of a solar system from rubble light years from our own, and could provide valuable insight into the formation of our solar system.

Pope will be looking to characterise the fraction of brown dwarfs (very small stars that don’t really have enough mass to kick off nuclear fusion of hydrogen) in binary systems with other bodies. He will also investigate the enigmatic star system, Eta Corvi, where planets appear to be acting like a conveyor belt, bringing icy comets from the cold outer disk in towards the separate warmer debris disk close into the star, where they are “torn apart, making this dust in the inner solar system”. Tuthill’s aperture mask will be crucial to obtaining a very high-resolution photo of that inner system.

These observations will mark the ever first space-based detection of exo-zodiacal dust. Zodiacal light from our own solar system can be seen from a dark sky site as a glowing backdrop to the zodiac constellations (and the path of the Sun through the sky during the day) and is basically “dusty material within the inner solar system produced by long term degradation of asteroids”, says Pope.

This light, he says, could really be a “land mine for studies of direct imaging of exoplanets”, suggesting that astronomers hunting for exoplanets may not be able to see them if the background glow of the exo-Zodiacal dust is too strong.

All three groups mentioned above (along with countless other Australian collaborations) are working hard to release initial research papers within weeks, as scientists race each other to get the publicly available data analysed and published.

https://cosmosmagazine.com/space/james-webb-space-telescope-treasure-trove/

 

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The James Webb Space Telescope has captured the Cartwheel Galaxy in vivid pinks

We can’t get enough of this telescope.

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lenticular galaxy 500 million light years away has just been papped by everyone’s new favourite space telescope, and it looks incredible.

Taken by the James Webb Space Telescope (JWST), the new image of the Cartwheel Galaxy highlights the galaxy’s two rings — a bright inner ring and a surrounding, outer ring which looks a bit like the spokes on a wheel.

The inner ring contains lots of hot dust, and the brightest areas are home to gigantic young star clusters. The outer ring, which has expanded for about 440 million years, is dominated by star formation and supernovas.

Astronomers believe the galaxy – located in the Sculptor constellation – was once a normal spiral galaxy, but a collision with a smaller galaxy created the wagon wheel effect.

The pink image is a composite from Webb’s Near-Infrared Camera (NIRCam) which is the main camera, and the Mid Infrared Instrument (MIRI). You can see the MIRI data in red in the composite image above, and in blue in the photo below.

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The Cartwheel Galaxy has three companions… G1 – the smaller irregular spiral at the top and G2 – the compact spiral at the bottom. The third companion is further away and can’t be seen in this image.

Finally, the image below shows what Hubble’s version of the Cartwheel Galaxy cluster looks like.

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https://cosmosmagazine.com/space/jwst-cartwheel-galaxy-new-image-pinks/

 

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16:29:51 - August 18, 2022

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Exoplanets will be among the pioneering investigations of the James Webb Space Telescope. Scientists hope that the telescope will shed light on hot Jupiter exoplanet atmospheres with molten rain, hurling vaporized rock or crystals from up high.

"On Earth, a lot of these minerals are jewels," Tiffany Kataria, who is an exoplanetary scientist at NASA's Jet Propulsion Laboratory, said in a statement(opens in new tab). "A geologist would study them as rocks on Earth, but they can form clouds on exoplanets. That's pretty wild."

Read more: James Webb Space Telescope will seek clouds of vaporized gems on exoplanets

https://www.space.com/news/live/james-webb-space-telescope-updates

 

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First exoplanet picture from James Webb Space Telescope

Take a look at another world in four colours.

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The James Webb Space Telescope (JWST) has continued its dazzling tour of the galaxy, with its first picture of an exoplanet.

The exoplanet, HIP 65426 b, is a gas giant almost 400 light-years away from Earth.

The planet is roughly nine times the mass of Jupiter, and only about 15-20 million years old: a fraction of Earth’s 4.5 billion years.

It orbits the star HIP 65426 – but it’s about 100 times further out from the star than Earth is from our sun. This distance makes it easier to spot.

Previously, it’s been difficult to capture pictures of exoplanets, because they are shrouded in light from their star.

But Webb’s  instruments can block out the star’s light and focus on planets. These masks which filter the light, called coronagraphs, are not new – but combining them with the telescope’s sensitive instruments is opening up new arenas.

The JWST captured the exoplanet in four different hues of infrared light, using its MIRI and NIRCam instrument.

Each of these pictures represents different wavelengths of infrared light: from right to left, 3.00, 4.44, 11.4, and 15.5 micrometres, respectively.

https://cosmosmagazine.com/space/exoplanet-jwst/

 

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19 minutes ago, CaaC (John) said:

The planet is roughly nine times the mass of Jupiter, and only about 15-20 million years old: a fraction of Earth’s 4.5 billion years.

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HIP 65426 b is a gas giant exoplanet that orbits an A-type star. Its mass is 9 Jupiters, it takes 630.7 years to complete one orbit of its star, and is 92 AU from its star. Its discovery was announced in 2017. NASA's James Webb Space Telescope was used to directly image the planet in 2022.

The image, as seen through four different light filters, shows how Webb’s powerful infrared gaze can easily capture worlds beyond our solar system, pointing the way to future observations that will reveal more information than ever before about exoplanets.

Taking direct images of exoplanets is challenging because stars are so much brighter than planets. The HIP 65426 b planet is more than 10,000 times fainter than its host star in the near-infrared, and a few thousand times fainter in the mid-infrared.

In each filter image, the planet appears as a slightly differently shaped blob of light. That is because of the particulars of Webb’s optical system and how it translates light through the different optics.

“Obtaining this image felt like digging for space treasure,” said Aarynn Carter, a postdoctoral researcher at the University of California, Santa Cruz, who led the analysis of the images. “At first all I could see was light from the star, but with careful image processing I was able to remove that light and uncover the planet.”

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Why do all the stars have 8 points in the James Webb images? An astronomer explains

Understand JWST's distinctive diffraction spikes with this handy guide.

With the release of the first processed images from the James Webb Space Telescope (JWST), it’s clear that this technological marvel is going to revolutionise our understanding of the Universe. With many discoveries to come, one, perhaps more trivial, aspect of the results has raised a few questions of its own: why do JWST star images have eight spikes emanating from them?

The spikes are not real, they are a consequence of how light interacts with the optical system of the telescope. They are created by the process of diffraction, an effect which occurs within every telescope when light encounters an edge. You may have seen similar ‘diffraction spikes’ on images produced by other telescopes.

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Diffraction spikes are typically produced in telescopes which use a secondary mirror held in front of the main mirror; it’s the secondary supports that create them. The JWST has a secondary mirror held in front of the main segmented mirror. There are three supports, one vertical and two angled at 150º to the vertical. Both edges of each support produce a diffraction spike at right angles to the edge. As a result, the three supports produce six diffraction spikes.

Surprisingly, the spikes produced by the JWST’s secondary supports aren’t the most prominent. It’s the edges of the hexagonal mirror sections that produce the most dramatic diffraction spikes, six arranged at 60-degree intervals.

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With the hexagonal mirror sections producing six spikes and the secondary supports a further six, you might expect to see twelve diffraction spikes in total. Clever design means that four of the secondary support spikes overlap four of the mirror section spikes and are hidden as a result. Look at a star in one of the JWST’s images and you’ll see the six large spikes from the hexagonally segmented primary mirror, plus two smaller ones from the vertical secondary support. The effect is easiest to see on brighter stars.

If you look carefully at a typical diffraction spike, you’ll see that it appears like a dashed line. This is caused by interference, the diffracted light waves reinforcing and cancelling one another as the spike is formed.

https://www.sciencefocus.com/space/diffraction-spikes-jwst/

 

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Tarantula Nebula photographed in unprecedented detail

Newly released mosaic from the James Webb Space Telescope peers through the cosmic dust to reveal never-before-seen young stars.

A mere 161,000 light-years away in the Large Magellanic Cloud, a small satellite galaxy of the Milky Way, is the Tarantula Nebula. Although the wispy swirls of clouds give a sense of serenity the Tarantula Nebula is actually one of the largest, and most violent star-forming regions in our Local Group.

The Local Group is essentially our galactic neighbourhood, of which our own Milky Way is a part. The biggest member of the group is the Andromeda Galaxy, while keen eyes (under dark and clear skies) may also be able to spot the more distant Triangulum Galaxy, thanks to its relatively bright apparent magnitude. Dozens of smaller dwarf galaxies are also members of the Local Group.

This incredible mosaic image, viewed with JWST's Near-Infrared Camera (NIRCam), stretches 340 light-years across, although the total width of the nebula is more than 1,000 light-years. The nebula is named after the web-like appearance of its dusty filaments that can be seen in previous images, the cavity in the centre resembling a burrowing tarantula’s home, lined with silk.

The nebula is a hotbed for some of the hottest and most massive stars known to astronomers, and in the centre, sparkling blue with massive young stars, is star cluster R136, its most active region.

"R136 sits in the middle of the larger cluster called NGC2070," says Professor Mark McCaughrean, senior advisor for science and exploration at the European Space Agency (ESA).

"R136 is a giant cluster of young stars, far exceeding anything in our own Milky Way galaxy, with almost half a million solar masses. It’s often suggested that it may be a proto-globular cluster, and its huge cumulative luminosity is what lights up the Tarantula Nebula, of which the new JWST image only shows a small fraction," McCaughrean explains.

Blistering radiation has blown away the dusty cocoons that once surrounded these protostars. Left behind is only the densest material, sculpted into pillars and ridges able to resist erosion from these torrential stellar winds.

Within these pillars are more newly-forming protostars. They too, will eventually emerge from their own cosmic cocoons and take their turn in shaping the nebula.

"The JWST image of the Tarantula Nebula was made using mosaics made through four separate infrared filters, F090W, F200W, F335M, and F444W, at 0.9, 2.0, 3.35, and 4.44 microns, respectively," McCaughrean says.

"The first, second, and fourth filters are all broad-band, capturing lots of starlight and nebular emissions. The third, the F335M filter, isolates an important emission line of polycyclic aromatic hydrocarbons, a strong tracer of dust."

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The Tarantula Nebula as imaged by the Hubble Space Telescope © NASA, ESA, and E. Sabbi/STScI

"The colour coding in the image is F090W as blue, F200W as green, F335M as orange, and F444W as red. The latter two filters make the dust in the region appear to 'glow' in orange-red colours. In the equivalent Hubble images, these regions are dark," explains McCaughrean.

https://www.sciencefocus.com/news/tarantula-nebula-james-webb-space-telescope/

 

 

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Has Webb spotted the first stars?

Dense globular clusters in Webb’s First Deep Field image may contain the universe’s oldest and first stars

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If you have never looked at the First Deep Field image captured by the James Webb Space Telescope, you need to.

Within the beautifully detailed image, you can see crowds of some of the universe’s earliest galaxies, sparkling like jewels through the vast expanse of space and time.

Looking deeper into the image, a Canadian research team has discovered the most distant globular clusters ever identified, which may contain the first and oldest stars in the universe. Finding these is a task for which Webb was specifically

“Webb was built to find the first stars and the first galaxies and to help us understand the origins of complexity in the universe, such as the chemical elements and the building blocks of life,” says Lamiya Mowla, Dunlap Fellow at the Dunlap Institute for Astronomy & Astrophysics at the University of Toronto and co-lead author of the study.

An image of a globular cluster
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The researchers focussed on the Sparkler galaxy, known for the small yellow-red dot ‘sparkles’ of star clusters surrounding it. Five of the 12 ‘sparkles’ analysed turned out to be globular clusters, which are typically found in the bulge and the halo around galaxies and contain many old and red stars. Because they are so tightly-packed, these clusters are typically very stable and last for billions of years.

The find was made by the aptly named CANUCS: Canadian NIRISS Unbiased Cluster Survey.

The globular clusters were identified by the CANUCS team due to the lack of oxygen lines in the NIRISS (Near-Infrared Imager and Slitless Spectrograph) data.

The presence of oxygen is important. If detected, it would suggest the clusters were much younger and actively engaged in star formation.

https://cosmosmagazine.com/science/physics/webb-spotted-first-oldest-stars/

 

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Cyclic carbon circling black holes – as seen by James Webb Space Telescope

Astronomers are surprised to find some small organic molecules hovering in unpleasant conditions.

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Data from the James Webb Space Telescope (JWST) has revealed the presence of carbon-based molecules near black holes at the centres of distant galaxies – right where astronomers assumed they weren’t.

Polycyclic aromatic hydrocarbons (PAHs) are small organic molecules very common in the universe (organic in the chemical sense: containing carbon and hydrogen).

But until this new data, from JWST’s MIRI, it was thought that they couldn’t exist close to black holes: they’d be pulled apart instead.

“The JWST MIRI provides us with a fantastic opportunity to observe galaxies in a way that just hasn’t been possible up until now,” says Dr Ismael García-Bernete, a researcher at Oxford University and lead author on a paper describing the research, published in Astronomy & Astrophysics.

“We were excited to find that these organic molecules can actually survive in extremely harsh conditions.”

PAHs produce bright infra-red light, which makes them prime candidates for investigating with JWST.

The researchers investigated the centres of three different galaxies, showing there were PAHs in each, in the vicinity of the galaxies’ central supermassive black holes.

But the black holes did have an effect on the PAHs. There were more large, and neutral, PAHs near the black holes – meaning smaller, charged molecules still got destroyed.

“This research is of great interest to the wider astronomy community, particularly those focused on the formation of planets and stars in the most distant and faint galaxies,” says García-Bernete.

“It is incredible to think that we can observe PAH molecules in the nuclear region of a galaxy, and the next step is to analyse a larger sample of active galaxies with different properties.

“This will enable us to better understand how PAH molecules survive and which are their specific properties in the nuclear region.

“Such knowledge is key to using PAHs as an accurate tool for characterising the amount of star formation in galaxies, and thus, how galaxies evolve over time.”

https://cosmosmagazine.com/space/pahs-jwst-black-hole/

 

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Oct 20, 2022

NASA’s Webb Uncovers Dense Cosmic Knot in The Early Universe

Astronomers looking into the early universe have made a surprising discovery using NASA’s James Webb Space Telescope: a cluster of massive galaxies in the process of forming around an extremely red quasar. The result will expand our understanding of how galaxy clusters in the early universe came together and formed the cosmic web we see today.

A quasar, a special type of active galactic nucleus (AGN), is a compact region with a supermassive black hole at the center of a galaxy. Gas falling into a supermassive black hole makes the quasar bright enough to outshine all the galaxy’s stars.

The quasar Webb explored, called SDSS J165202.64+172852.3, existed 11.5 billion years ago. It is unusually red not just because of its intrinsic red color, but also because the galaxy’s light has been redshifted by its vast distance. That made Webb, having unparalleled sensitivity in infrared wavelengths, perfectly suited to examine the galaxy in detail.

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This quasar is one of the most powerful known galactic nuclei that’s been seen at such an extreme distance. Astronomers had speculated that the quasar’s extreme emission could cause a “galactic wind,” pushing free gas out of its host galaxy and possibly greatly influencing future star formation there.

To investigate the movement of the gas, dust and stellar material in the galaxy, the team used the telescope’s Near Infrared Spectrograph (NIRSpec). This powerful instrument uses a technique called spectroscopy to look at the movement of various outflows and winds surrounding the quasar. NIRSpec can simultaneously gather spectra across the telescope’s whole field of view, instead of just from one point at a time, enabling Webb to simultaneously examine the quasar, its galaxy and the wider surroundings.

Previous studies by NASA’s Hubble Space Telescope and other observatories called attention to the quasar’s powerful outflows, and astronomers had speculated that its host galaxy could be merging with some unseen partner. But the team was not expecting Webb’s NIRSpec data to clearly indicate it was not just one galaxy, but at least three more swirling around it. Thanks to spectra over a broad area, the motions of all this surrounding material could be mapped, resulting in the conclusion that the red quasar was in fact part of a dense knot of galaxy formation.

“There are few galaxy protoclusters known at this early time. It’s hard to find them, and very few have had time to form since the big bang,” said astronomer Dominika Wylezalek of Heidelberg University in Germany, who led the study with Webb. “This may eventually help us understand how galaxies in dense environments evolve. It’s an exciting result.”

Using the observations from NIRSpec, the team was able to confirm three galactic companions to this quasar and show how they are connected. Archival data from Hubble hint that there may be even more. Images from Hubble’s Wide Field Camera 3 had shown extended material surrounding the quasar and its galaxy, prompting its selection for this study into its outflow and the effects on its host galaxy. Now, the team suspects they could have been looking at the core of a whole cluster of galaxies – only now revealed by Webb’s crisp imaging.

"Our first look at the data quickly revealed clear signs of major interactions between the neighboring galaxies,” shared team member Andrey Vayner of Johns Hopkins University in Baltimore, Maryland. “The sensitivity of the NIRSpec instrument was immediately apparent, and it was clear to me that we are in a new era of infrared spectroscopy."

The three confirmed galaxies are orbiting each other at incredibly high speeds, an indication that a great deal of mass is present. When combined with how closely they are packed into the region around this quasar, the team believes this marks one of the densest known areas of galaxy formation in the early universe. “Even a dense knot of dark matter isn’t sufficient to explain it,” Wylezalek says. “We think we could be seeing a region where two massive halos of dark matter are merging together.” Dark matter is an invisible component of the universe that holds galaxies and galaxy clusters together, and is thought to form a “halo” that extends beyond the stars in these structures.

The study conducted by Wylezalek’s team is part of Webb’s investigations into the early universe. With its unprecedented ability to look back in time, the telescope is already being used to investigate how the first galaxies were formed and evolved, and how black holes formed and influenced the structure of the universe. The team is planning follow-up observations into this unexpected galaxy proto-cluster, and hope to use it to understand how dense, chaotic galaxy clusters like this one form, and how it’s affected by the active, supermassive black hole at its heart.

https://www.nasa.gov/feature/goddard/2022/nasa-s-webb-uncovers-dense-cosmic-knot-in-the-early-universe

 

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Webb Reveals New Details in Pillars of Creation

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Our James Webb Space Telescope has captured a new image of the famous Pillars of Creation—first imaged by the Hubble Space Telescope in 1995—that reveals new details about the region. The three-dimensional pillars look like majestic rock formations but are far more permeable. These columns are made up of cool interstellar gas and dust that sometimes appear semi-transparent in near-infrared light.

Webb’s new view of the Pillars of Creation will help researchers revamp their models of star formation by identifying far more precise counts of newly formed stars, along with the quantities of gas and dust in the region. Over time, they will begin to build a clearer understanding of how stars form and burst out of these dusty clouds over millions of years.

Download the full-resolution, uncompressed version and supporting visuals from the Space Telescope Science Institute.

Image Credits: NASA, ESA, CSA, STScI; Joseph DePasquale (STScI), Anton M. Koekemoer (STScI), Alyssa Pagan (STScI).

https://www.nasa.gov/image-feature/webb-reveals-new-details-in-pillars-of-creation

 

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NASA’s James Webb telescope spots ‘sparkling’ galaxy that may contain the oldest stars ever seen

Published: 03rd November, 2022 at 16:35

The first deep field image released by the telescope shows a distant galaxy in unprecedented detail.

The earliest stars ever seen may have been spotted by NASA’s James Webb Space Telescope, a study carried out by astronomers at the University of Toronto has found.

Researchers from the university’s Dunlap Institute for Astronomy & Astrophysics in the University of Toronto spotted the distant cluster of stars after analysing data from the space telescope’s first deep field image.

Dubbed ‘The Sparkler Galaxy’, thanks to the series of small yellow dots that surround it, the cosmic object lies around nine billion light-years away from Earth.

The team believes that the sparkles that give the galaxy its name are old globular clusters - ancient collections of stars that formed during a galaxy’s infancy that contain clues about the earliest phases of its formation and growth.

Previously, using the Hubble Space Telescope - the James Webb Telescope's predecessor, astronomers were not able to determine what the sparkles surrounding the galaxy were.

The increased resolution and sensitivity of the JWST has now allowed them to analyse them in detail, including determining their age, for the first time.

The data analysed was captured by the JWST's Near-Infrared Camera (NIRCam), which is able to detect incredibly faint objects using wavelengths of light that are invisible to the human eye.

“Looking at the first images from JWST and discovering old globular clusters around distant galaxies was an incredible moment – one that wasn’t possible with previous Hubble Space Telescope imaging,” said study co-author Dr Kartheik G. Iyer, of the Dunlap Institute for Astronomy & Astrophysics.

“Since we could observe the sparkles across a range of wavelengths, we could model them and better understand their physical properties – like how old they are and how many stars they contain. We hope the knowledge that globular clusters can be observed at from such great distances with JWST will spur further science and searches for similar objects.”

https://www.sciencefocus.com/news/nasas-james-webb-telescope-spots-sparkling-galaxy-that-may-contain-the-oldest-stars-ever-seen/

 

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Nov 16, 2022

NASA’s Webb Catches Fiery Hourglass as New Star Forms

NASA’s James Webb Space Telescope has revealed the once-hidden features of the protostar within the dark cloud L1527, providing insight into the beginnings of a new star. These blazing clouds within the Taurus star-forming region are only visible in infrared light, making it an ideal target for Webb’s Near-Infrared Camera (NIRCam).

The protostar itself is hidden from view within the “neck” of this hourglass shape. An edge-on protoplanetary disk is seen as a dark line across the middle of the neck. Light from the protostar leaks above and below this disk, illuminating cavities within the surrounding gas and dust.

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The region’s most prevalent features, the clouds colored blue and orange in this representative-color infrared image, outline cavities created as material shoots away from the protostar and collides with surrounding matter. The colors themselves are due to layers of dust between Webb and the clouds. The blue areas are where the dust is thinnest. The thicker the layer of dust, the less blue light is able to escape, creating pockets of orange.

Webb also reveals filaments of molecular hydrogen that have been shocked as the protostar ejects material away from it. Shocks and turbulence inhibit the formation of new stars, which would otherwise form all throughout the cloud. As a result, the protostar dominates the space, taking much of the material for itself.

Despite the chaos that L1527 causes, it’s only about 100,000 years old - a relatively young body. Given its age and its brightness in far-infrared light as observed by missions like the Infrared Astronomical Satellite, L1527 is considered a class 0 protostar, the earliest stage of star formation. Protostars like these, which are still cocooned in a dark cloud of dust and gas, have a long way to go before they become full-fledged stars. L1527 doesn’t generate its own energy through nuclear fusion of hydrogen yet, an essential characteristic of stars. Its shape, while mostly spherical, is also unstable, taking the form of a small, hot, and puffy clump of gas somewhere between 20 and 40% the mass of our Sun.

As the protostar continues to gather mass, its core gradually compresses and gets closer to stable nuclear fusion. The scene shown in this image reveals L1527 doing just that. The surrounding molecular cloud is made up of dense dust and gas being drawn to the center, where the protostar resides. As the material falls in, it spirals around the center. This creates a dense disk of material, known as an accretion disk, which feeds material to the protostar. As it gains more mass and compresses further, the temperature of its core will rise, eventually reaching the threshold for nuclear fusion to begin.

The disk, seen in the image as a dark band in front of the bright center, is about the size of our solar system. Given the density, it’s not unusual for much of this material to clump together - the beginnings of planets. Ultimately, this view of L1527 provides a window into what our Sun and solar system looked like in their infancy.

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

https://www.nasa.gov/feature/goddard/2022/nasa-s-webb-catches-fiery-hourglass-as-new-star-forms

 

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Dec 8, 2022
NASA’s Webb Indicates Several Stars ‘Stirred Up’ Southern Ring Nebula

Lee esta historia en español aquí.

Some of the first data from NASA’s James Webb Space Telescope has shown there were at least two, and possibly three, more unseen stars that crafted the oblong, curvy shapes of the Southern Ring Nebula. Plus, for the first time, by pairing Webb’s infrared images with existing data from ESA’s (European Space Agency’s) Gaia observatory, researchers were able to precisely pinpoint the mass of the central star before it created the nebula. A team of almost 70 researchers led by Orsola De Marco of Macquarie University in Sydney, Australia, analyzed Webb’s 10 highly detailed exposures of this dying star to produce these results.

A.png

Let’s start with the top-tier celebrity of this particular “party,” the star that sloughed off its layers of gas and dust over thousands of years. It appears red in the image on the left because it is surrounded by an orbiting, dusty disk similar in size to our solar system’s Kuiper Belt. While some stars expel their layers as solo acts “on stage,” researchers propose that there were a few companions with front row seats – and at least one that may have joined the central star before it began to create the Southern Ring Nebula. “With Webb, it’s like we were handed a microscope to examine the universe,” De Marco said. “There is so much detail in its images. We approached our analysis much like forensic scientists to rebuild the scene.”

It’s common for small groups of stars, spanning a range of masses, to form together and continue to orbit one another as they age. The team used this principle to step back in time, by thousands of years, to determine what might explain the shapes of the colorful clouds of gas and dust.

First, they focused on the aging star that cast off its layers and is still surrounded by a dusty red “cloak” of dust. Extensive research about these types of aging stars shows that dusty cloaks like these must take the form of dusty disks that orbit the star. A quick dive into the data revealed the disk. “This star is now smaller and hotter, but is surrounded by cool dust,” said Joel Kastner, another team member, from the Rochester Institute of Technology in New York. “We think all that gas and dust we see thrown all over the place must have come from that one star, but it was tossed in very specific directions by the companion stars.”

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Before the dying star shed its layers, the team proposes that it interacted with one or even two smaller companion stars. During this intimate “dance,” the interacting stars may have launched two-sided jets, which appeared later as roughly paired projections that are now observed at the edges of the nebula. “This is much more hypothetical, but if two companions were interacting with the dying star, they would launch toppling jets that could explain these opposing bumps,” De Marco explained. The dusty cloak around the dying star points to these interactions.

Where are those companions now? They are either dim enough to hide, camouflaged by the bright lights of the two central stars, or have merged with the dying star.  

The complex shapes of the Southern Ring Nebula are more evidence of additional unseen companions – its ejections are thinner in some areas and thicker in others. A third closely interacting star may have agitated the jets, skewing the evenly balanced ejections like spin art. In addition, a fourth star with a slightly wider orbit might have also “stirred the pot” of ejections, like a spatula running through batter in the same direction each time, generating the enormous set of rings in the outer reaches of the nebula.

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What about the very bright blue-white star in Webb’s images? Think of the fifth star like the most responsible party guest that continues to orbit the dying star slowly, predictably, and calmly.

The two images shown here each combine near-infrared and mid-infrared data to isolate different components of the nebula. The image at left highlights the very hot gas that surrounds the central stars. The image at right traces the star’s scattered molecular outflows that have reached farther into the cosmos.

The team's paper, entitled "The messy death of a multiple star system and the resulting planetary nebula as observed by JWST," will be published in Nature Astronomy on Dec. 8.

https://www.nasa.gov/feature/goddard/2022/nasa-s-webb-indicates-several-stars-stirred-up-southern-ring-nebula

 

 

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