Aerospace & Defence

Even more James Webb Space Telescope discoveries

22nd November 2023
Harry Fowle
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The JWST has continued to peer far into the unknown this year, unlocking secrets of the universe that were once only concepts in our imagination. Join us as we dive into even more of the latest James Webb Space Telescope discoveries.

Continuing to push the cutting-edge and heralding a modern era of astronomy, as previously mentioned here, the James Webb Space Telescope (JWST) has brought fresh revelations to the forefront of the scientific community, demonstrating what leading engineering can achieve. From discovering the secrets of our own protoplanetary creation to the creation of the earliest galactic clusters, the JWST can do it all.

Discovering protoclusters – Opening Pandora’s Cluster

For the very first time, a protocluster of just seven ancient galaxies has been discovered thanks to the JWST’s powerful measurement capabilities and the gravitational lensing of Pandora’s Cluster. With a redshift of 7.9, this places these objects and an age just 650 million years after the big bang.

The seven galaxies that have been confirmed at a redshift of 7.9, which is around 650 million years after the big bang. This makes these galaxies the earliest to be spectroscopically confirmed as a part of a developing cluster. Credits: NASA, ESA, CSA, T. Morishita (IPAC). Image processing: A. Pagan (STScI).

The James Webb Space Telescope has only just begun its journey to shed light on the formative years of the universe which until this point was an impossibility. A key part of this understanding is figuring out the formation and assembly of the first galaxies, which is why a cluster of seven ancient galaxies is so intriguing. Based on the collected data, astronomers agree that this cluster is simply a protocluster which will eventually develop into a something of similar scale to the Coma Cluster, a colossal structure of today’s universe being more than 20 million light-years in diameter.

Takahiro Morishita, Researcher at IPAC-California Institute of Technology, commented: “This is a very special, unique site of accelerated galaxy evolution, and Webb gave us the unprecedented ability to measure the velocities of these seven galaxies and confidently confirm that they are bound together in a protocluster.”

The exact measurements taken by Webb’s Near-Infrared Spectrograph (NIRSpec) played a critical role in confirming the collective distance of the galaxies and their rapid movement within a dark matter halo – exceeding a staggering two million mph (approx. 1,000 kilometres per second).

This spectral data enabled astronomers to create models and predict the future evolution of this protocluster, extending to the current era in the universe. The anticipation that the protocluster will evolve to mirror the Coma Cluster suggests that it may become one of the most densely packed galaxy clusters known, potentially comprising thousands of galaxies.

Investigating the initial formation of vast clusters seen in the modern universe such as Pandora and Coma have been notoriously challenging. This difficulty arises because the universe’s expansion stretches light from visible wavelengths into the infrared spectrum, an area where astronomers previously lacked high-resolution data. Webb’s infrared instruments were specifically designed to address these gaps, providing crucial insights into the early chapters of the universe’s story.

Understanding the centre of our Milky Way – Sagittarius C

The JWST has also been able to analyse the chaotic centre of our own Milky Way galaxy in unprecedented detail to highlight never before seen features that astronomers have yet to properly understand or explain.

An image of the Sagittarius C region at the Milky Way’s dense core made possible by the NIRCam of the JWST. There is an estimated 500,000 stars in this image, along with unidentified features, such as the sporadic needle-like structures present in the large region of ionised hydrogen, which is shown in cyan. Credit: NASA, ESA, CSA, STScI, and S. Crowe (University of Virginia).

The Observation Team’s Principal Investigator Samuel Crowe, an undergraduate student at the University of Virginia in Charlottesville, said: “There’s never been any infrared data on this region with the level of resolution and sensitivity we get with Webb, so we are seeing lots of features here for the first time. Webb reveals an incredible amount of detail, allowing us to study star formation in this sort of environment in a way that wasn’t possible previously.”

“The galactic centre is the most extreme environment in our Milky Way galaxy, where current theories of star formation can be put to their most rigorous test,” added Professor Jonathan Tan, one of Crowe’s advisors at the University of Virginia.

Thanks to the powerful Webb telescope, the galactic centre, which sits around 25,000 light-years from Earth, is close enough to study on an individual star-scale, allowing an unprecedented amount of information on star formation and how cosmic environments can impact this to be taken.

Understanding planet formation – Protoplanetary discs

Scientists have also been able to utilise the JWST’s Mid-Infrared Instrument (MIRI) to shed light on the process of planet formation. Webb's observations of water vapor in protoplanetary disks have validated a key physical process; the movement of ice-coated solids from the colder, outer regions of the disk into areas where rocky planets form.

This graphic, based on data from Webb's MIRI, compares pebble drift and water distribution in compact and extended disks. In the compact disk, ice-covered pebbles move smoothly towards the warmer star area, vaporizing ice at the snow line and enriching forming rocky planets with water. In contrast, the extended disk's rings and gaps hinder pebble movement, limiting water delivery to the inner region as fewer pebbles cross the snow line. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI).

The long-held theories suggest that icy pebbles, originating in the same region as comets in our solar system, form in the outer areas of protoplanetary disks and are crucial to planet formation. These theories posit that pebbles should migrate inward towards the star, influenced by friction in the gaseous disk, thereby contributing both solid materials and water to forming planets.

A critical aspect of this theory is the expectation that as these icy pebbles approach the warmer area inside the “snowline”—where ice turns into vapor—they should release substantial amounts of cold-water vapor. This phenomenon was precisely what Webb detected.

Andrea Banzatti, the Principal Investigator from Texas State University, San Marcos, Texas, remarked, “Webb finally revealed the connection between water vapor in the inner disk and the drift of icy pebbles from the outer disk. This finding opens up exciting prospects for studying rocky planet formation with Webb!”

Colette Salyk, a team member from Vassar College in Poughkeepsie, New York, added insight into the dynamic nature of planet formation. “In the past, we had this very static picture of planet formation, almost like there were these isolated zones that planets formed out of,” she explained. “Now we actually have evidence that these zones can interact with each other. It’s also something that is proposed to have happened in our solar system.”

The researchers utilised Webb’s MIRI to study the disks of four sun-like stars, two compact – HP Tau and GK Tau – and two extended – CI Tau and IQ Tau. These stars are estimated to be between 2-3 million years old, making them cosmic newborns.

The observations from Webb's MIRI indicate that compact disks likely experience effective pebble drift, transporting materials to regions within a distance comparable to Neptune’s orbit. In contrast, extended disks are believed to retain their pebbles in multiple rings, extending up to six times Neptune’s orbital distance.

These observations aimed to verify if compact disks exhibit higher water abundance in their inner regions, indicative of efficient pebble drift supplying substantial solid mass and water to inner planets. The team utilised MIRI’s Medium-Resolution Spectrometer (MRS) for its sensitivity to water vapor in disks.

The findings align with expectations, showing a notable presence of cool water in compact disks compared to their larger counterparts.

A record-breaking black hole – UHZ1

The JWST doesn’t have to go it alone and is often being used to enable the wide array of different specialist telescopes in NASA’s arsenal. Combining the data of Webb and NASA’s Chandra X-ray observatory, a research team was able to discover a blackhole at the earliest stages of its development ever observed. Such a finding may help explain how the first supermassive blackholes formed in the ancient universe.

This image shows the vast Abell 2744 cluster in the foreground, with UHZ1 located behind it, which is enhanced in the top left. Using the JWST the host-galaxy was able to be found, which Chandra and its powerful X-ray measurement tools could then analyse. X-ray emissions, highlighted in purple here, are telltale signs of a growing supermassive blackhole. Credit: X-ray: NASA/CXC/SAO/Ákos Bogdán; Infrared: NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/L. Frattare & K. Arcand.

Akos Bogdan, Researcher at the Centre for Astrophysics at Harvard & Smithsonian (CfA), commented: “We needed Webb to find this remarkably distant galaxy and Chandra to find its supermassive black hole.”

Bogdan's team discovered a black hole in galaxy UHZ1, initially thought to be in the direction of galaxy cluster Abell 2744, located 3.5 billion light-years from Earth. However, Webb data revealed UHZ1 is much farther, at 13.2 billion light-years away, dating back to when the universe was just 3% of its current age.

Subsequent two-week observations with the Chandra telescope detected intense X-ray emitting gas in UHZ1, indicative of a growing supermassive black hole. Gravitational lensing from matter in Abell 2744 magnified the light from UHZ1 and the X-rays from the surrounding gas by about four times, enhancing the infrared signal captured by Webb and enabling Chandra to identify the faint X-ray source.

This discovery is crucial for understanding the early growth of supermassive black holes post-big bang. It questions whether they originate from massive gas cloud collapses, forming black holes of about 10,000 to 100,000 solar masses, or from explosions of early stars, leading to black holes between 10 and 100 solar masses.

Andy Goulding from Princeton University explained: “There are physical limits to how quickly black holes can grow, but those born more massive have a head start. It’s akin to planting a sapling versus starting with a seed; the former grows into a full-size tree faster.”

Bogdan's team has discovered compelling evidence suggesting the black hole they found was born with a substantial mass. Based on the luminosity and energy of the observed X-rays, the black hole's mass is estimated to be between 10 and 100 million solar masses. This is notably similar to the total stellar mass of its host galaxy, contrasting sharply with black holes in nearby universe galaxies, which typically constitute only about 0.1% of their host galaxy's stellar mass.

This black hole's significant mass at such an early stage in the universe, along with its X-ray output and the galaxy's brightness as observed by Webb, align with 2017 theoretical predictions by co-author Priyamvada Natarajan from Yale University. Natarajan had theorised the existence of an "Outsize Black Hole" forming directly from the collapse of a massive gas cloud.

The team intends to utilise these findings, along with other data from Webb and combined observations from different telescopes, to develop a more comprehensive understanding of the early universe.

Read about more JWST discoveries here, and let us know your thoughts in the comments below!

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