James Webb Space Telescope beats its own record with potential most distant galaxies

Jan 27, 2020
By Keith Cooper

The treasure trove of early data from the James Webb Space Telescope has unearthed the most distant galaxies ever seen.

jwst image.jpeg
The first publicly released science-quality image from NASA's James Webb Space Telescope, revealed on July 11, 2022, is the deepest infrared view of the universe to date. (Image credit: NASA, ESA, CSA, and STScI)

Astronomers are now discovering record-breaking distant galaxies by the dozen while sifting through the treasure trove of data now being collected by the James Webb Space Telescope (JWST or Webb). Among them are several galaxies dating back to just over 200 million years after the Big Bang.

Prior to the launch of the James Webb Space Telescope, the most distant confirmed galaxy known was GN-z11, which astronomers saw as it was about 420 million years after the Big Bang, giving it what astronomers call a redshift of 11.6. (Redshift describes how much the light coming from a galaxy has been stretched as the universe expands. The higher the redshift, the farther back in time we see a galaxy.)

Just a week after the release of the first science images from JWST, astronomers were reporting the detection of galaxies at redshift 13, equating to about 300 million years after the Big Bang. Now, a new wave of scientific results is smashing past that record, with some astronomers reporting the detection of galaxies up to a redshift of 20. If true, then we are seeing these galaxies as they existed about 200 million years after the Big Bang.

That's a big if: At this stage, none of these redshift values are confirmed. To confirm the distances of these galaxies will require spectroscopic analysis, which splits the light from an object into what scientists call a spectrum. That analysis will come later. Nevertheless, it seems clear that JWST is fully capable of detecting galaxies from this long-lost era.

The galaxies have been detected using different techniques. Astronomers led by Haojing Yan of the University of Missouri-Columbia used the gravitational lens created by the galaxy cluster SMACS J0723 to detect 88 candidate galaxies beyond a redshift of 11, including a handful estimated to be at a redshift of 20. If validated, these galaxies would be, by far, the most distant ever detected. Because of cosmic expansion, today these galaxies would be over 35 billion light-years away from us.

Two other papers report finding high-redshift galaxies in patches of the sky where JWST has simply taken deep exposures, without resorting to gravitational lensing. These images are part of the Cosmic Evolution Early Release Science (CEERS) survey, which consists of images of 10 different patches of sky by JWST's Near-Infrared Camera (NIRCam). JWST's Near-Infrared Spectrograph (NIRSpec) joins in observations of six of those patches, while the space telescope's Mid-Infrared Instrument (MIRI) studies four.

One team of astronomers, led by Ph.D. student Callum Donnan of the University of Edinburgh, found a candidate galaxy at a redshift of 16.7, which equates to just 250 million years after the Big Bang. The team also found five other galaxies with a redshift greater than 12, all of which exceed the redshift record set by JWST's predecessor and now colleague, the Hubble Space Telescope.

Meanwhile, using the same observations from CEERS, another team led by Steven Finkelstein of the University of Texas at Austin discovered a galaxy with a redshift of 14.3, placing it 280 million years after the Big Bang, which the researchers have named "Maisie's Galaxy" after Finkelstein's daughter. The astronomers found that this galaxy may have also been seen by the Hubble Space Telescope, but not recognized at that time. If a closer look at the archived data does reveal the galaxy, then Maisie's Galaxy must produce very strong ultraviolet light from a powerful burst of star formation for Hubble to have spotted it.

Indeed, all the distant galaxy candidates display evidence for strong ultraviolet light emission, enough to possibly settle the debate as to what ionized the hydrogen gas in the universe, bringing an end to the so-called "Cosmic Dark Ages." Over the years, astronomers have suggested causes ranging from radiation from the first stars and galaxies to outflows of radiation from the first supermassive black holes.

In their paper, Donnan's team calculate the "galaxy ultraviolet luminosity function" between redshifts of 8 and 15. This function is an average of the amount of ultraviolet light associated with galaxies at any particular epoch. The value is strongly tied to star formation, because the more hot young stars are being formed in a galaxy, the more ultraviolet light it emits. Donnan's team concluded that there is more than enough ultraviolet radiation being produced by the stars in these early galaxies to ionize the universe.

The amount of ultraviolet light (redshifted into the longer wavelengths of infrared, making it visible to JWST), coupled with the abundance of high-redshift galaxies that it is finding so early in its mission, suggests that galaxies were plentiful in the earliest history of the universe. Contrary to some expectations, the rate of star formation might decline gradually the farther back in time we look, rather than there being a sharp drop-off beyond redshift 11.

"Should follow up spectroscopy validate [these redshifts], [it means that] our universe was already aglow with galaxies less than 300 million years after the Big Bang," Finkelstein's team wrote in their paper.

Now that JWST has discovered these strong galaxy candidates at vast distances, the next questions are how much farther back in time JWST can see and whether it will be enough to discover the very first galaxies that existed, perhaps just 100 million years after the Big Bang. Such a discovery would require necessitate a large dose of luck, since it would rely on fortuitous gravitational lensing to bring primordial galaxies into view.

The Yan paper can be found here(opens in new tab); the Donnan paper here(opens in new tab); and the Finkelstein paper here(opens in new tab).

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See: https://www.space.com/james-webb-space-telescope-new-most-distant-galaxies?utm_campaign=58E4DE65-C57F-4CD3-9A5A-609994E2C5A9

The following is a partial element from the Donnan paper:

The evolution of the galaxy UV luminosity function at redshifts z ≃ 8 – 15 from deep JWST and ground-based near-infrared imaging

by C. T. Donnan1★, D. J. McLeod1, J. S. Dunlop1, R. J. McLure1, A. C. Carnall1, R. Begley1, F. Cullen1
M. L. Hamadouche1, R. A. A. Bowler2, H. J. McCracken3, B. Milvang-Jensen4, 5, A. Moneti3 & T. Targett6
1Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ. UK
2Jodrell Bank Centre for Astrophysics, University of Manchester, Oxford Road, Manchester, UK
3 Institut d’Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Université, 98 bis boulevard Arago, 75014 Paris, France
4 Cosmic Dawn Center (DAWN)
5 Niels Bohr Institute, University of Copenhagen, Jagtvej 128, 2200 Copenhagen, Denmark
6 Department of Physics and Astronomy, Sonoma State University, 1801 East Cotati Avenue, Rohnert Park, CA 94928-3609, US

We re-reduce and analyse the available James Webb Space Telescope (JWST) ERO and ERS NIRCam imaging (SMACS0723, GLASS, CEERS) in combination with the latest deep ground-based near-infrared imaging in the COSMOS field (provided by UltraVISTA DR5) to produce a new measurement of the evolving galaxy UV luminosity function (LF) over the redshift range 𝑧 = 8 − 15. This yields a new estimate of the evolution of UV luminosity density (𝜌UV), and hence cosmic star-formation rate density (𝜌SFR) out to within < 300 Myr of the Big Bang. Our results confirm that the high-redshift LF is best described by a double power-law (rather than a Schechter) function, and that the LF and the resulting derived 𝜌UV (and thus 𝜌SFR), continues to decline gradually and steadily over this redshift range (as anticipated from previous studies which analysed the pre-existing data in a consistent manner). We provide details of the 55 high-redshift galaxy candidates, 44 of which are new, that have enabled this new analysis. Our sample contains 6 galaxies at 𝑧 ≥ 12, one of which appears to set a new redshift record as an apparently robust galaxy candidate at 𝑧 ≃ 16.7, the properties of which we therefore consider in detail. The advances presented here emphasize the importance of achieving high dynamic range in studies of early galaxy evolution, and re-affirm the enormous potential of forthcoming larger JWST programmes to transform our understanding of the young Universe.

See: https://arxiv.org/pdf/2207.12356.pdf

The following is a partial element from the Finkelstein paper:

A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ∼ 14 Galaxy in Early JWST CEERS Imaging

Steven L. Finkelstein, Micaela B. Bagley, Pablo Arrabal Haro, Mark Dickinson, Henry C. Ferguson, Jeyhan S. Kartaltepe, Casey Papovich, Denis Burgarella, Dale D. Kocevski, Marc Huertas-Company, Kartheik G. Iyer, Anton M. Koekemoer, Rebecca L. Larson, Pablo G. Pe ́rez-Gonza ́lez, Caitlin Rose, Sandro Tacchella, Stephen M. Wilkins, Katherine Chworowsky, Aubrey Medrano, Alexa M. Morales, Rachel S. Somerville, L. Y. Aaron Yung, Adriano Fontana, Mauro Giavalisco, Andrea Grazian, Norman A. Grogin, Lisa J. Kewley, Allison Kirkpatrick, Peter Kurczynski, Jennifer M. Lotz,
Laura Pentericci, Nor Pirzkal, Swara Ravindranath, Russell E. Ryan Jr., Jonathan R. Trump, Guang Yang,
and from The CEERS Team:
Omar Almaini, Ricardo O. Amor ́ın, Marianna Annunziatella, Bren E. Backhaus, Guillermo Barro,
Peter Behroozi, Eric F. Bell, Rachana Bhatawdekar, Laura Bisigello, Volker Bromm, Ve ́ronique Buat,
Fernando Buitrago, Antonello Calabro`, Caitlin M. Casey, Marco Castellano, O ́scar A. Cha ́vez Ortiz, Laure Ciesla, Nikko J. Cleri, Seth H. Cohen, Justin W. Cole, Kevin C. Cooke, M. C. Cooper, Asantha R. Cooray, Luca Costantin, Isabella G. Cox, Darren Croton, Emanuele Daddi, Romeel Dave ́, Alexander de la Vega, Avishai Dekel, David Elbaz, Vicente Estrada-Carpenter, Sandra M. Faber, Vital Ferna ́ndez, Keely D. Finkelstein, Jonathan Freundlich, Seiji Fujimoto, Ángela Garc ́ıa-Arguma ́nez, Jonathan P. Gardner, Eric Gawiser, Carlos Go ́mez-Guijarro, Yuchen Guo, Kurt Hamblin, Timothy S. Hamilton, Nimish P. Hathi, Benne W. Holwerda, Michaela Hirschmann, Taylor A. Hutchison, Saurabh W. Jha, Shardha Jogee, Ste ́phanie Juneau, Intae Jung, Susan A. Kassin, Aure ́lien Le Bail, Gene C. K. Leung, Ray A. Lucas, Benjamin Magnelli, Kameswara Bharadwaj Mantha, Jasleen Matharu, Elizabeth J. McGrath, Daniel H. McIntosh, Emiliano Merlin, Bahram Mobasher, Jeffrey A. Newman, David C. Nicholls, Viraj Pandya, Marc Rafelski, Kaila Ronayne, Paola Santini, Lise-Marie Seille ́, Ekta A. Shah, Lu Shen, Raymond C. Simons, Gregory F. Snyder, Elizabeth R. Stanway, Amber N. Straughn, Harry I. Teplitz, Brittany N. Vanderhoof, Jesu ́s Vega-Ferrero, Weichen Wang, Benjamin J. Weiner, Christopher N. A. Willmer, Stijn Wuyts And Jorge A. Zavala

We report the discovery of a candidate galaxy with a photo-z of z ∼ 14 in the first epoch of the JWST Cosmic Evolution Early Release Science (CEERS) Survey. Following conservative selection criteria we identify a robust source at z = 14.3+0.4 (1σ uncertainty) with m = 27.8, and phot −1.1 F 277W>5σ detections in five filters. This object (Maisie’s Galaxy) exhibits F150W−F200W>2.5 mag with a blue continuum slope, resulting in 99.99% (87%) of the photo-z PDF favoring z > 10 (13). All data quality images show no artifacts at the candidate’s position, and independent analyses consistently find a strong preference for z > 13. The source may be marginally detected in HST F160W, which if included would widen the lower-redshift bound to z ∼12.5, and would require very strong Lyα emission (􏰀 300A rest-EW) indicating an early ionized bubble. Its colors are inconsistent with Galactic stars, and it is resolved (rh =330+/−30 pc). Maisie’s Galaxy appears modestly massive (log M∗/M⊙∼ 8.5) and highly star-forming (log sSFR∼−7.9 yr−1), with a blue rest-UV color (β ∼ −2.3) indicating little dust though not extremely low metallicities. While the presence of this source is in tension with most predictions, it agrees with empirical extrapolations assuming a smoothly declining SFR density. Should followup spectroscopy validate this redshift, our Universe was already aglow with galaxies less than 300 Myr after the Big Bang.

See: https://web.corral.tacc.utexas.edu/ceersdata/papers/Maisies_Galaxy.pdf

Before closing, the Hubble Space Telescope detected the most distant galaxy yet discovered, GN-z11, which has a recessional velocity of z=10.957, is visible from 13.4 billion years ago when the universe was 3% of its current age, or 407 million years after The Big Bang, and which lies some 32 billion light years away.

most distant galaxy hubble actual.jpeg
The most distant galaxy ever discovered in the known Universe, GN-z11, has its light come to us from 13.4 billion years ago: when the Universe was only 3% its current age: 407 million years old. The distance from this galaxy to us, taking the expanding Universe into account, is an incredible 32.1 billion light-years, and is only possible because of a serendipitous lack of light-blocking dust along the line-of-sight to this galaxy. A combination of Hubble and Spitzer observations were used to discover this galaxy, whose light is so severely redshifted that it only appears in the infrared portion of the spectrum. NASA, ESA, AND G. BACON (STSCI)

The increasing number of high-redshift galaxies being discovered may be explained as being cosmic infants. These relatively small galaxies span only 1,000 or so light-years across and contain just tens of millions of stars; whereas modern galaxies can host hundreds of billions of stars and super giant elliptical galaxies may be host an extensive, faint halo of stars extending to megaparsec (million parsecs, where a parsec = 3.26 light years) scales . Astronomers estimate that some of the cosmic babies being identified by the JWS are approximately 100 million years old.

Scientists haven't yet identified any of the very first galaxies in the universe, which may lie at redshift 25 or beyond. Still, the new detections represent generations of galaxies that followed closely after, which scientists now see in the early stages of development thanks to The James Webb Space Telescope.
Jan 27, 2020
jwestdog -

I am excited as you are about the JWST, however, it too, has its limits. Here is some further information which I believe will better flesh out your ideas.

COBE*, WMAP**, and Planck*** all saw further back than JWST, though it's true that JWST will see decidedly farther back than the Hubble Space Telescope. JWST was designed not to see the beginnings of the universe, but to see a period of the universe's history that we have not seen yet - the earliest galaxies, a few of which the JWST has already done in its first images.

Image from COBE.

WMAP map.jpeg
Image from WMAP

planck images.jpeg

A Planck image.

Specifically the JWST would like to see the first objects that formed as the universe cooled down after the Big Bang. That time period is perhaps hundreds of millions of years later than the one COBE, WMAP, and Planck were built to see. We think that the tiny ripples of temperature they observed were the seeds that eventually grew into galaxies. We don't know exactly when the universe made the first stars and galaxies - or how for that matter. That is what we are building JWST to help answer.

The only way we can see back to the time when these objects were forming is to look very far away and very deep into the universe. Hubble isn't big enough, cold enough or designed to peer into the far infrared enough to see the faint heat signals of these objects that are so far away and, hence, so far back in time.

The chemical elements of life were first produced in the first generation of stars after the Big Bang. We are here today because of them - and we want to better understand how that came to be! We have ideas, we have predictions, but we don't know. One way or another the first stars must have influenced our own history, beginning with stirring up the interstellar medium and producing the heavier chemical elements besides hydrogen and helium when these stars end their lifetimes and explode or expand to the red giant phase of stellar evolution. So if we really want to know where our atoms came from, and how the little planet Earth came to be capable of supporting life, we need to observe and measure what happened at the very beginning or as close to the Big Bang as we can get.

*COBE - The purpose of the Cosmic Background Explorer (COBE) mission was to take precise measurements of the diffuse radiation between 1 micrometer and 1 cm over the whole celestial sphere. The following quantities were measured: (1) the spectrum of the 3 K radiation over the range 100 micrometers to 1 cm; (2) the anisotropy of this radiation from 3 to 10 mm; and, (3) the spectrum and angular distribution of diffuse infrared background radiation at wavelengths from 1 to 300 micrometers.

See : https://science.nasa.gov/missions/cobe

** WMAP - The Wilkinson Microwave Anisotropy Probe (WMAP) is a NASA Explorer mission that launched June 2001 to make fundamental measurements of cosmology -- the study of the properties of our universe as a whole. WMAP has been stunningly successful, producing our new Standard Model of Cosmology. WMAP's data stream has now ended.

See: https://map.gsfc.nasa.gov

*** Planck - is a European Space Agency mission with significant participation from NASA. It was launched into space in May 2009, and now orbits the second Lagrange point of our Earth-sun system, about 1.5 million km (930,000 miles) away. NASA Planck mission website. Planck mission on ESA website

NASA played key roles in the mission's development, and will provide important contributions to data and science analyses. NASA's Jet Propulsion Laboratory in Pasadena, Calif., built critical components of Planck's science instruments, including bolometers for the mission's high-frequency instrument; a 20 Kelvin cryocooler for both the low- and high-frequency instruments; and amplifier technology for the low-frequency instrument.

The U.S. Planck team will play a major role in data and science analyses, with a primary tool being the Franklin supercomputer at the National Energy Research Scientific Computing Center in Berkeley, Calif. One of the world's fastest computers, Franklin will handle the most computationally intensive analysis jobs for the Planck team worldwide. The team will produce a catalogue of cosmic objects, called the Early Release Compact Source Catalogue, which will be released to the public nine months after completion of the first sky survey.

See: https://www.nasa.gov/mission_pages/planck/overview.html