JWST now owns the top 8 spots for most distant objects

One year ago, in 2022, Hubble still held the cosmic distance record.

A section of the GOODS-N field, which contains the galaxy GN-z11, the most distant galaxy ever observed. Originally, Hubble data indicated a redshift of 11.1, a distance of 32.1 billion light-years, and an inferred age of the Universe of 407 million light-years at the time this light was emitted. With better JWST data, we know this galaxy is a little closer: at a redshift of 10.60 corresponding to an age of the Universe of 433 million years.

Galaxy GN-z11, discovered in 2015, was discovered in a deeply-imaged field.

Over the course of 50 days, with a total of over 2 million seconds of total observing time (the equivalent of 23 complete days), the Hubble eXtreme Deep Field (XDF) was constructed from a portion of the prior Hubble Ultra Deep Field image. Combining light from ultraviolet through visible light and out to Hubble’s near-infrared limit, the XDF represented humanity’s deepest view of the cosmos: a record that stood until it was broken by JWST. In the red box, where no galaxies are seen by Hubble, the JWST’s JADES survey revealed the most distant galaxy to date: JADES-GS-z13-0. Extrapolating beyond what we see to what we know and expect must exist, we infer a total of ~2 sextillion stars within the observable Universe.

Its light arrived from 13.4 billion years ago: when the Universe was just 3% of its present age.

Only because the most distant galaxy spotted by Hubble, GN-z11, is located in a region where the intergalactic medium is mostly reionized, was Hubble able to reveal it to us at the present time, breaking the prior record held by EGSY8p7. Other galaxies that are at this same distance but aren’t along a serendipitously greater-than-average line of sight as far as reionization goes can only be revealed at longer wavelengths, and by observatories such as JWST. At present, GN-z11 has been relegated to the 9th most distant galaxy known as of 2024: in the JWST era.

Its bright, massive nature along an unusually transparent line-of-sight enabled Hubble to see it.

Before JWST, there were about 40 ultra-distant galaxy candidates known, primarily via Hubble’s observations. Early JWST results revealed many more ultra-distant galaxy candidates, but now a whopping 717 of them have been found in just the JADES 125 square-arcminute field-of-view. The entire night sky is more than 1 million times grander in scale. While some candidates will survive spectroscopic follow-up, others will not. Much science remains to be conducted, but very few facilities (other than JWST itself) are capable of conducting the needed follow-ups.

No ground-based or space-based telescope ever saw farther, until JWST.

This section of one of our deepest views of the Universe, acquired with JWST, overlaps with data from the Hubble eXtreme Deep Field. Compared to Hubble, JWST reveals an enormous number of objects previously invisible to Hubble, even with only ~4% of the observing time. Most of these galaxies are small and low-mass, but are forming stars rapidly right now, enabling JWST to reveal their presence.

JWST’s larger size, better resolution, and infrared optimization provide superior observations.

This region of space, viewed first iconically by Hubble and later by JWST, shows an animation that switches between the two. Both images still have fundamental limitations, as they were acquired from within our inner Solar System, where the presence of zodiacal light influences the noise floor of our instruments, and cannot easily be removed. The extra presence of point-like red objects in JWST images, also known as “little red dots,” has finally been explained, but other puzzles still remain.

Today, in 2023, GN-z11 has fallen to 9th place of all-time.

This incredible view of the distant Universe is revealed in spectacular detail with the second data release from the JADES Collaboration. Using data primarily from NIRCam but augmented spectroscopically by NIRSpec, stars and galaxies near and far, as well as some of the most distant cosmic objects of all, are all revealed alongside one another.

The JADES collaboration helped immensely.

This image shows the region of study of the JWST Advanced Deep Extragalactic Survey (JADES). This area includes and contains the Hubble eXtreme Deep Field and reveals new galaxies at record-breaking distances that Hubble could not see. The colors on JWST images are not “true color” but rather are assigned based on a variety of choices. This image, released in December of 2022, has since been augmented by follow-on observations within the same region of space, with spectroscopic observations required to determine the distance to these galaxies.

Three new galaxies:

• JADES-GS-z13-0,
• JADES-GS-z12-0,
• and JADES-GS-z10-0,

now hold the #1, #3, and #10 spots.

The four most distant galaxies identified as part of JADES, thus far, include three that surpass the threshold for “most distant galaxy” previously set by Hubble. With no more than a quarter of the total JADES data taken thus far, this record will likely fall again, perhaps multiple times, over the coming months and years, but the unambiguous feature of the Lyman break can clearly be seen. The most distant, JADES-GS-z13-0, took the record from Hubble in December of 2022, and still holds it today. Although these are among the youngest galaxies ever discovered, their stellar populations are not pristine.

JADES determined GN-z11 to be more recent: from 433, not 407, million years after the Big Bang.

A section of the GOODS-N field, which contains the galaxy GN-z11, the most distant galaxy ever observed. Originally, Hubble data indicated a redshift of 11.1, a distance of 32.1 billion light-years, and an inferred age of the Universe of 407 million light-years at the time this light was emitted. With better JWST data, we know this galaxy is a little closer: at a redshift of 10.60 corresponding to an age of the Universe of 433 million years.

Another galaxy spectroscopically measured with JADES, UDFj-39546284, holds the #6 spot.

First imaged in 2009 and identified in 2010 as a likely candidate for an ultra-distant galaxy, UDFj-39546284 was only spectroscopically confirmed by the JADES collaboration in 2023, using JWST data. It sits at a redshift of 11.58, making it the 6th most distant galaxy of all-time at present.

The UNCOVER collaboration has also surpassed Hubble’s old record.

This image shows the full imaging field of the JWST UNCOVER Treasury Survey, which takes up about 0.007 square degrees in the sky. In this tiny patch of space, some ~50,000 objects are revealed, with the majority of them not associated with the imaged cluster, Abell 2744, at all, but rather as background galaxies that are affected by the gravity of the cluster itself. No signs of matter-antimatter annihilation are seen here, indicating that all stars and galaxies shown are made of matter, not antimatter. However, many gravitationally lensed background galaxies are among the most distant ever discovered.

UNCOVER-z13 and UNCOVER-z12 hold the #2 and #4 all-time spots, for now.

This JWST view of a portion of Pandora’s Cluster, Abell 2744, showcases multiple galaxies that are located far beyond the cluster itself, many from within the first 1 billion years of cosmic history. Gravitational lensing renders these otherwise invisible galaxies accessible to JWST, with the UNCOVER survey presently holding the #2 and #4 spots as far as most distant galaxies of all-time are concerned.

The GLASS and CEERS collaborations also viewed the early, ultra-distant Universe with JWST.

An ultra-distant galaxy candidate within the GLASS-JWST survey volume, along with the contours that mark the detection of doubly-ionized oxygen by ALMA. The JWST and ALMA data point toward the same object with an offset of just 0.5 arc-seconds. This galaxy, now known as GLASS-z12, is presently the 5th most distant astronomical object ever discovered.

GLASS-z12 holds the #5 spot, while Maisie’s galaxy and CEERS2 588 hold spots #7 and #8.

This collection of several different JWST “pointings” from the CEERS photometric survey contains Maisie’s Galaxy, a high-redshift galaxy candidate that was recently spectroscopically confirmed to be at z=11.4, placing it just 390 million years after the Big Bang. It also contains four separate, nearby galaxies at a confirmed redshift of 4.9, indicating a galaxy proto-cluster just 1.2 billion years after the Big Bang.

The Guinness Record Book is wrong; definitive spectroscopic confirmation is required to determine a galaxy’s distance.

In the entirety of the spectra taken by our most powerful observatories, including ALMA, of galaxy HD1, only one tentative signature for a line emerges: for a doubly-ionized oxygen line. Its confidence does not rise to the “gold standard” required to announce a discovery, and will remain only a high-redshift galaxy candidate (despite what Guinness says) until JWST takes a bona fide spectrum of this object.

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