James Webb Space Telescope

[Tank]

This is a recent picture of Neptune, its ring system, local moons and major moon, Titan, taken by the James Webb Space Telescope (JWST).

Titan is the second largest moon in the solar system, Ganymede being the largest. Our Moon it the 5th largest. Titan's image is distorted because the exposure was set for  Neptune resulting in Titan being over exposed as it is essentially a ball of ice and thus white.

[Tank]

What a time to be alive!

Earliest and most distant galaxy ever observed

The James Webb Space Telescope has smashed its own record for detecting the most distant known galaxy.

Called JADES-GS-z14-0, the collection of stars was spied as it was a mere 290 million years after the Big Bang.

Put another way - if the Universe is 13.8 billion years old, it means we're observing the galaxy when the cosmos was only 2% of its current age.

[Asmodean]

...Joe Wanks So Tenderly.

One of these days, fitting random ramblings to JWST will cease to amuse an easily-amused The Asmo. that day, however, is not today.

[Recusant]

About those far-distant galaxies: some anomalous findings (pretty much always cool, in astronomy/cosmology).

"Tiny bright objects discovered at dawn of universe baffle scientists | PennState

A recent discovery by NASA's James Webb Space Telescope (JWST) confirmed that luminous, very red objects previously detected in the early universe upend conventional thinking about the origins and evolution of galaxies and their supermassive black holes.

An international team, led by Penn State researchers, using the NIRSpec instrument aboard JWST as part of the RUBIES survey identified three mysterious objects in the early universe, about 600-800 million years after the Big Bang, when the universe was only 5% of its current age. They announced the discovery today (June 27) in Astrophysical Journal Letters.

The team studied spectral measurements, or intensity of different wavelengths of light emitted from the objects. Their analysis found signatures of "old" stars, hundreds of millions of years old, far older than expected in a young universe.

The researchers said they were also surprised to discover signatures of huge supermassive black holes in the same objects, estimating that they are 100 to 1,000 times more massive than the supermassive black hole in our own Milky Way. Neither of these are expected in current models of galaxy growth and supermassive black hole formation, which expect galaxies and their black holes to grow together over billions of years of cosmic history.

"We have confirmed that these appear to be packed with ancient stars — hundreds of millions of years old — in a universe that is only 600-800 million years old. Remarkably, these objects hold the record for the earliest signatures of old starlight," said Bingjie Wang, a postdoctoral scholar at Penn State and lead author on the paper. "It was totally unexpected to find old stars in a very young universe. The standard models of cosmology and galaxy formation have been incredibly successful, yet, these luminous objects do not quite fit comfortably into those theories."

The researchers first spotted the massive objects in July of 2022, when the initial dataset was released from JWST. The team published a paper in Nature several months later announcing the objects' existence.

At the time, the researchers suspected the objects were galaxies, but followed up their analysis by taking spectra to better understand the true distances of the objects, as well as the sources powering their immense light.

The researchers then used the new data to draw a clearer picture of what the galaxies looked like and what was inside of them. Not only did the team confirm that the objects were indeed galaxies near the beginning of time, but they also found evidence of surprisingly large supermassive black holes and a surprisingly old population of stars.

[Continues . . .]

The paper is open access:

"RUBIES: Evolved Stellar Populations with Extended Formation Histories at z ∼ 7–8 in Candidate Massive Galaxies Identified with JWST/NIRSpec" | The Astrophysical Journal Letters

Abstract:

The identification of red, apparently massive galaxies at z > 7 in early James Webb Space Telescope (JWST) photometry suggests a strongly accelerated time line compared to standard models of galaxy growth. A major uncertainty in the interpretation is whether the red colors are caused by evolved stellar populations, dust, or other effects such as emission lines or active galactic nuclei (AGNs).

Here we show that three of the massive galaxy candidates at z = 6.7–8.4 have prominent Balmer breaks in JWST/NIRSpec spectroscopy from the RUBIES program. The Balmer breaks demonstrate unambiguously that stellar emission dominates at λ_rest = 0.4 μm and require formation histories extending hundreds of millions of years into the past in galaxies only 600–800 Myr after the big bang.

Two of the three galaxies also show broad Balmer lines, with Hβ FWHM > 2500 km s−1, suggesting that dust-reddened AGNs contribute to, or even dominate, the spectral energy distributions of these galaxies at λ_rest ≳ 0.6 μm. All three galaxies have relatively narrow [o iii] lines, seemingly ruling out a high-mass interpretation if the lines arise in dynamically relaxed, inclined disks.

Yet the inferred masses also remain highly uncertain. We model the high-quality spectra using Prospector to decompose the continuum into stellar and AGN components and explore limiting cases in stellar/AGN contribution. This produces a wide range of possible stellar masses, spanning M⋆ ∼ 109−1011M⊙.

Nevertheless, all fits suggest a very early and rapid formation, most of which follow with a truncation in star formation. Potential origins and evolutionary tracks for these objects are discussed, from the cores of massive galaxies to low-mass galaxies with overmassive black holes. Intriguingly, we find all of these explanations to be incomplete; deeper and redder data are needed to understand the physics of these systems.

[Tank]

I love the JWST!

[Asmodean]

Tank loves himself-self Just Wasting Some Time.

...Jeering with substantial tenacity..?

...Joking while serving tea?

...Jousting With Sir Tristan?

...Jam with some toast..?

 

The Asmo shall figure it out, see if He shall not!

[Recusant]

The Asmo shall figure it out, see if He shall not!

I for one eagerly await the results. 

Meanwhile a couple more items . . .

"Webb captures a staggering quasar-galaxy merger in the remote universe" | Phys.org

An international research group led by the Italian National Institute for Astrophysics (INAF) and comprising 34 research institutes and universities worldwide utilized the Near-Infrared Spectrograph (NIRSpec) on board the James Webb Space Telescope (JWST) to witness the dramatic interaction between a quasar inside the PJ308–21 system and two massive satellite galaxies in the distant universe.

The observations, made in September 2022, unveiled unprecedented and awe-inspiring details, providing new insights into the growth of galaxies in the early universe. The results, presented July 5 during the European Astronomical Society (EAS 2024) meeting in Padua (Italy), will be published soon in Astronomy & Astrophysics.

Observations of this quasar (already described by the same authors in another study published last May), one of the first studied with NIRSpec when the universe was less than a billion years old (redshift z = 6.2342), have revealed data of sensational quality: the instrument "captured" the quasar's spectrum with an uncertainty of less than 1% per pixel.

The host galaxy of PJ308–21 shows high metallicity and photoionization conditions typical of an active galactic nucleus (AGN), whereas one of the satellite galaxies exhibits low metallicity (which refers to the abundance of chemical elements heavier than hydrogen and helium) and photoionization induced by star formation; a higher metallicity characterizes the second satellite galaxy, which is partially photoionized by the quasar.

The discovery has enabled astronomers to determine the mass of the supermassive black hole at the center of the system (about 2 billion solar masses). It also confirmed that both the quasar and the surrounding galaxies are highly evolved in mass and metal enrichment, and in constant growth.

[Continues . . .]

* * *

"Webb Sees a Star in the Midst of Formation" | Universe Today

In this JWST image, a young protostar is growing larger and emitting jets of material from
inside its molecular cloud.
Image Credit: NASA, ESA, CSA, STScI

Wherever the JWST looks in space, matter and energy are interacting in spectacular displays. The Webb reveals more detail in these interactions than any other telescope because it can see through dense gas and dust that cloak many objects.

In a new image, the JWST spots a young protostar only 100,000 years old.

The star is named L1527, and at this young age, it's still ensconced in the molecular cloud that spawned it. This is one of the reasons NASA built the JWST (with help from the ESA and the CSA.) The telescope can see through dust and gas to reveal the earliest stages of star formation.

This image was captured with MIRI, the Mid-Infrared Instrument. The young protostar is at the heart of it all, and it's still growing. It's accumulating mass from the protoplanetary disk that surrounds it. The disk is the tiny dark horizontal line at the image's center.

[Continues . . .]

[Tank]

I'm so glad I'm alive to witness these astonishing discoveries.

[Recusant]

Agreed sir. For those who appreciate learning a bit about the workings of the Universe and seeing parts of it in action this is a wonderful time. A lucky circumstance to be around to see what devices like Hubble and Webb can show us.

[Tank]

The vision of humanity has expanded so much from molecular microscopes to the JWST. Amazing.

[Recusant]

From this past February (though I don't think it's previously appeared here). . . The Hubble and Webb telescopes may be showing us the cause of reionization in the early Universe (the source of first effective light). With the usual pop-sci glossing into certainty something that is by its nature tentative.

"We Finally Know What Switched on The Lights at The Dawn of Time" | Science Alert

We finally know what brought light to the dark and formless void of the early Universe.

According to data from the Hubble and James Webb Space Telescopes, the origins of the free-flying photons in the early cosmic dawn were small dwarf galaxies that flared to life, clearing the fog of murky hydrogen that filled intergalactic space. A new paper about the research was published in February.

"This discovery unveils the crucial role played by ultra-faint galaxies in the early Universe's evolution," said astrophysicist Iryna Chemerynska of the Institut d'Astrophysique de Paris.

"They produce ionizing photons that transform neutral hydrogen into ionized plasma during cosmic reionization. It highlights the importance of understanding low-mass galaxies in shaping the Universe's history."

At the beginning of the Universe, within minutes of the Big Bang, space was filled with a hot, dense fog of ionized plasma. What little light there was wouldn't have penetrated this fog; photons would simply have scattered off the free electrons floating around, effectively making the Universe dark.

As the Universe cooled, after about 300,000 years, protons and electrons began to come together to form neutral hydrogen (and a little bit of helium) gas.

Most wavelengths of light could penetrate this neutral medium, but there was very little in the way of light sources to produce it. But from this hydrogen and helium, the first stars were born.

Those first stars delivered radiation that was strong enough to peel electrons away from their nuclei and reionize the gas. By this point, however, the Universe had expanded so much that the gas was diffuse, and could not prevent light from shining out.

By about 1 billion years after the Big Bang, the end of the period known as the cosmic dawn, the Universe was entirely reionized. Ta-da! The lights were on.

But because there's so much murk in the cosmic dawn, and because it's so dim and far away across time and space, we've had trouble seeing what's there.

Scientists thought that the sources responsible for most of the clearing must have been powerful – huge black holes whose accretion produces blazing light, for example, and large galaxies in the throes of star formation (baby stars produce a lot of UV light).

JWST was designed, in part, to peer into the cosmic dawn and try to see what lurks therein. It's been very successful, revealing all sorts of surprises about this crucial time in the formation of our Universe. Surprisingly, the telescope's observations now suggest that dwarf galaxies are the key player in reionization.

[Continues . . .]

The paper is behind a paywall but I found a preprint version--the abstract is the same in both.

"Most of the photons that reionized the Universe came from dwarf galaxies" | ArXiv

Abstract:

The identification of sources driving cosmic reionization, a major phase transition from neutral Hydrogen to ionized plasma around 600-800 Myr after the Big Bang has been a matter of intense debate.

Some models suggest that high ionizing emissivity and escape fractions (fesc) from quasars support their role in driving cosmic reionization. Others propose that the high fesc values from bright galaxies generates sufficient ionizing radiation to drive this process. Finally, a few studies suggest that the number density of faint galaxies, when combined with a stellar-mass-dependent model of ionizing efficiency and fesc, can effectively dominate cosmic reionization. However, so far, low-mass galaxies have eluded comprehensive spectroscopic studies owing to their extreme faintness.

Here we report an analysis of eight ultra-faint galaxies (in a very small field) during the epoch of reionization with absolute magnitudes between M_UV ≈−17 to −15 mag (down to 0.005 L⋆). We find that faint galaxies during the Universe's first billion years produce ionizing photons with log(ξ_ion/ Hz erg⁻¹) =25.80±0.14, a factor of 4 higher than commonly assumed values. If this field is representative of the large scale distribution of faint galaxies, the rate of ionizing photons exceeds that needed for reionization, even for escape fractions of order 5%.

[Tank]

How interesting

[Recusant]

Galaxies in a Webb image appear to rotate in one direction more than the other. Two possible explanations are presented. The relatively mundane explanation (having to do with the physics of galaxies themselves, and perhaps that of our own galaxy) seems more likely to me than the other explanation: that the rotation "bias" comes from the Universe itself having a rotational velocity.

"Puzzling observation by JWST: Galaxies in the deep universe rotate in the same direction" | Phys.org

In images of the deep universe taken by the James Webb Space Telescope Advanced Deep Extragalactic Survey, the vast majority of the galaxies rotate in the same direction, according to research by Lior Shamir, associate professor of computer science at the Carl R. Ice College of Engineering. About two thirds of the galaxies rotate clockwise, while just about a third of the galaxies rotate counterclockwise.

The study—published in Monthly Notices of the Royal Astronomical Society—was done with 263 galaxies in the JADES field that were clear enough to identify their direction of rotation.

"The analysis of the galaxies was done by quantitative analysis of their shapes, but the difference is so obvious that any person looking at the image can see it," Shamir said. "There is no need for special skills or knowledge to see that the numbers are different. With the power of the James Webb Space Telescope, anyone can see it."

In a random universe, the number of galaxies that rotate in one direction should be roughly the same as the number of galaxies that rotate in the other direction. The fact that JWST shows that most galaxies rotate in the same direction is therefore unexpected.

[Continues . . .]

The paper is open access:

"The distribution of galaxy rotation in JWST Advanced Deep Extragalactic Survey" | Monthly Notices of the Royal Astronomical Society

Abstract:

JWST provides a view of the Universe never seen before, and specifically fine details of galaxies in deep space. JWST Advanced Deep Extragalactic Survey (JADES) is a deep field survey, providing unprecedentedly detailed view of galaxies in the early Universe. The field is also in relatively close proximity to the Galactic pole.

Analysis of spiral galaxies by their direction of rotation in JADES shows that the number of galaxies in that field that rotate in the opposite direction relative to the Milky Way galaxy is ~50  per cent higher than the number of galaxies that rotate in the same direction relative to the Milky Way. The analysis is done using a computer-aided quantitative method, but the difference is so extreme that it can be noticed and inspected even by the unaided human eye.

These observations are in excellent agreement with deep fields taken at around the same footprint by Hubble Space Telescope and JWST. The reason for the difference may be related to the structure of the early Universe, but it can also be related to the physics of galaxy rotation and the internal structure of galaxies. In that case the observation can provide possible explanations to other puzzling anomalies such as the H_o tension and the observation of massive mature galaxies at very high redshifts.