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NASA’s Webb Digs into Structural Origins of Disk Galaxies
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NASA, ESA, CSA, T. Tsukui (Australian National University).
Present-day disk galaxies often contain a thick, star-filled outer disk and an embedded thin disk of stars. For instance, our own Milky Way galaxy’s thick disk is approximately 3,000 light-years in height, and its thin disk is roughly 1,000 light-years thick.
How and why does this dual disk structure form? By analyzing archival data from multiple observational programs by NASA’s James Webb Space Telescope, a team of astronomers is closer to answers, as well as understanding the origins of disk galaxies in general.
The team carefully identified, visually verified, and analyzed a statistical sample of 111 edge-on disk galaxies at various periods — up to 11 billion years ago (or approximately 2.8 billion years after the big bang). This is the first time scientists have investigated thick- and thin-disk structures spanning such vast distances, bridging the gap between observers probing the early universe and galactic archaeologists seeking to understand our own galaxy’s history.
“This unique measurement of the thickness of the disks at high redshift, or at times in the early universe, is a benchmark for theoretical study that was only possible with Webb,” said Takafumi Tsukui, lead author of the paper and a researcher at the Australian National University in Canberra. “Usually, the older, thick disk stars are faint, and the young, thin disk stars outshine the entire galaxy. But with Webb’s resolution and unique ability to see through dust and highlight faint old stars, we can identify the two-disk structure of galaxies and measure their thickness separately.”
Image: A Sample of Galaxy Disks (NIRCam) Astronomers pulled from NASA’s James Webb Space Telescope’s data to analyze a sample of 111 edge-on galaxies. The team’s analysis suggests that thick disk formation occurs first, and thin disk formation follows. When this process occurs depends on the galaxy’s mass. NASA, ESA, CSA, T. Tsukui (Australian National University). Data Through Thick and Thin
By analyzing these 111 targets over cosmological time, the team was able to study single-disk galaxies and double-disk galaxies. Their results indicate that galaxies form a thick disk first, followed by a thin disk. The timing of when this takes place is dependent on the galaxy’s mass: high-mass, single-disk galaxies transitioned to two-disk structures around 8 billion years ago. In contrast, low-mass, single-disk galaxies formed their embedded thin disks later on, about 4 billion years ago.
“This is the first time it has been possible to resolve thin stellar disks at higher redshift. What’s really novel is uncovering when thin stellar disks start to emerge,” said Emily Wisnioski, a co-author of the paper at the Australian National University in Canberra. “To see thin stellar disks already in place 8 billion years ago, or even earlier, was surprising.”
A Turbulent Time for GalaxiesTo explain this transition from a single, thick disk to a thick and thin disk, and the difference in timing for high- and low-mass galaxies, the team looked beyond their initial edge-on galaxy sample and examined data showing gas in motion from the Atacama Large Millimeter/submillimeter Array (ALMA) and ground-based surveys.
By taking into consideration the motion of the galaxies’ gas disks, the team finds their results align with the “turbulent gas disk” scenario, one of three major hypotheses that has been proposed to explain the process of thick- and thin-disk formation. In this scenario, a turbulent gas disk in the early universe sparks intense star formation, forming a thick stellar disk. As stars form, they stabilize the gas disk, which becomes less turbulent and, as a result, thinner.
Since massive galaxies can more efficiently convert gas into stars, they settle sooner than their low-mass counterparts, resulting in the earlier formation of thin disks. The team notes that thick- and thin-disk formation are not siloed events: The thick disk continues to grow as the galaxy develops, though it’s slower than the thin disk’s rate of growth.
How This Applies to HomeWebb’s sensitivity is enabling astronomers to observe smaller and fainter galaxies, analogous to our own, at early times and with unprecedented clarity for the first time. In this study, the team noted that the transition period from thick disk to a thick and thin disk roughly coincides with the formation of the Milky Way galaxy’s thin disk. With Webb, astronomers will be able to further investigate Milky Way-like progenitors — galaxies that would have preceded the Milky Way — which could help explain our galaxy’s formation history.
In the future, the team intends to incorporate other data points into their edge-on galaxy sample.
“While this study structurally distinguishes thin and thick disks, there is still much more we would like to explore,” said Tsukui. “We want to add the type of information people usually get for nearby galaxies, like stellar motion, age, and metallicity. By doing so, we can bridge the insights from galaxies near and far, and refine our understanding of disk formation.”
These results were published in the Monthly Notices of the Royal Astronomical Society.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing 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 CSA (Canadian Space Agency).
To learn more about Webb, visit:
DownloadsClick any image to open a larger version.
View/Download all image products at all resolutions for this article from the Space Telescope Science Institute.
View/Download the research results from the Monthly Notices of the Royal Astronomical Society.
Media ContactsLaura Betz – laura.e.betz@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Abigail Major – amajor@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Hannah Braun – hbraun@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Article: Types of Galaxies
Video: Celestial Tour: Different types of galaxies
Article: Learn more about Webb’s views of nearby spiral galaxies
Visualization Video: Galaxy Traverse
Related For Kids En Español Keep Exploring Related Topics James Webb Space TelescopeWebb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…
Galaxies
Galaxies Stories
Universe
Share Details Last Updated Jun 26, 2025 Editor Marty McCoy Contact Laura Betz laura.e.betz@nasa.gov Related Terms
NASA’s Webb Digs into Structural Origins of Disk Galaxies
- Webb
- News
- Overview
- Science
- Observatory
- Multimedia
- Team
- More
NASA, ESA, CSA, T. Tsukui (Australian National University).
Present-day disk galaxies often contain a thick, star-filled outer disk and an embedded thin disk of stars. For instance, our own Milky Way galaxy’s thick disk is approximately 3,000 light-years in height, and its thin disk is roughly 1,000 light-years thick.
How and why does this dual disk structure form? By analyzing archival data from multiple observational programs by NASA’s James Webb Space Telescope, a team of astronomers is closer to answers, as well as understanding the origins of disk galaxies in general.
The team carefully identified, visually verified, and analyzed a statistical sample of 111 edge-on disk galaxies at various periods — up to 11 billion years ago (or approximately 2.8 billion years after the big bang). This is the first time scientists have investigated thick- and thin-disk structures spanning such vast distances, bridging the gap between observers probing the early universe and galactic archaeologists seeking to understand our own galaxy’s history.
“This unique measurement of the thickness of the disks at high redshift, or at times in the early universe, is a benchmark for theoretical study that was only possible with Webb,” said Takafumi Tsukui, lead author of the paper and a researcher at the Australian National University in Canberra. “Usually, the older, thick disk stars are faint, and the young, thin disk stars outshine the entire galaxy. But with Webb’s resolution and unique ability to see through dust and highlight faint old stars, we can identify the two-disk structure of galaxies and measure their thickness separately.”
Image: A Sample of Galaxy Disks (NIRCam) Astronomers pulled from NASA’s James Webb Space Telescope’s data to analyze a sample of 111 edge-on galaxies. The team’s analysis suggests that thick disk formation occurs first, and thin disk formation follows. When this process occurs depends on the galaxy’s mass. NASA, ESA, CSA, T. Tsukui (Australian National University). Data Through Thick and ThinBy analyzing these 111 targets over cosmological time, the team was able to study single-disk galaxies and double-disk galaxies. Their results indicate that galaxies form a thick disk first, followed by a thin disk. The timing of when this takes place is dependent on the galaxy’s mass: high-mass, single-disk galaxies transitioned to two-disk structures around 8 billion years ago. In contrast, low-mass, single-disk galaxies formed their embedded thin disks later on, about 4 billion years ago.
“This is the first time it has been possible to resolve thin stellar disks at higher redshift. What’s really novel is uncovering when thin stellar disks start to emerge,” said Emily Wisnioski, a co-author of the paper at the Australian National University in Canberra. “To see thin stellar disks already in place 8 billion years ago, or even earlier, was surprising.”
A Turbulent Time for GalaxiesTo explain this transition from a single, thick disk to a thick and thin disk, and the difference in timing for high- and low-mass galaxies, the team looked beyond their initial edge-on galaxy sample and examined data showing gas in motion from the Atacama Large Millimeter/submillimeter Array (ALMA) and ground-based surveys.
By taking into consideration the motion of the galaxies’ gas disks, the team finds their results align with the “turbulent gas disk” scenario, one of three major hypotheses that has been proposed to explain the process of thick- and thin-disk formation. In this scenario, a turbulent gas disk in the early universe sparks intense star formation, forming a thick stellar disk. As stars form, they stabilize the gas disk, which becomes less turbulent and, as a result, thinner.
Since massive galaxies can more efficiently convert gas into stars, they settle sooner than their low-mass counterparts, resulting in the earlier formation of thin disks. The team notes that thick- and thin-disk formation are not siloed events: The thick disk continues to grow as the galaxy develops, though it’s slower than the thin disk’s rate of growth.
How This Applies to HomeWebb’s sensitivity is enabling astronomers to observe smaller and fainter galaxies, analogous to our own, at early times and with unprecedented clarity for the first time. In this study, the team noted that the transition period from thick disk to a thick and thin disk roughly coincides with the formation of the Milky Way galaxy’s thin disk. With Webb, astronomers will be able to further investigate Milky Way-like progenitors — galaxies that would have preceded the Milky Way — which could help explain our galaxy’s formation history.
In the future, the team intends to incorporate other data points into their edge-on galaxy sample.
“While this study structurally distinguishes thin and thick disks, there is still much more we would like to explore,” said Tsukui. “We want to add the type of information people usually get for nearby galaxies, like stellar motion, age, and metallicity. By doing so, we can bridge the insights from galaxies near and far, and refine our understanding of disk formation.”
These results were published in the Monthly Notices of the Royal Astronomical Society.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing 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 CSA (Canadian Space Agency).
To learn more about Webb, visit:
DownloadsClick any image to open a larger version.
View/Download all image products at all resolutions for this article from the Space Telescope Science Institute.
View/Download the research results from the Monthly Notices of the Royal Astronomical Society.
Media ContactsLaura Betz – laura.e.betz@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Abigail Major – amajor@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Hannah Braun – hbraun@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Article: Types of Galaxies
Video: Celestial Tour: Different types of galaxies
Article: Learn more about Webb’s views of nearby spiral galaxies
Visualization Video: Galaxy Traverse
Related For Kids En Español Keep Exploring Related Topics James Webb Space TelescopeWebb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…
Galaxies
Galaxies Stories
Universe
Share Details Last Updated Jun 26, 2025 Editor Marty McCoy Contact Laura Betz laura.e.betz@nasa.gov Related Terms
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NASA, Australia Team Up for Artemis II Lunar Laser Communications Test
As NASA prepares for its Artemis II mission, researchers at the agency’s Glenn Research Center in Cleveland are collaborating with The Australian National University (ANU) to prove inventive, cost-saving laser communications technologies in the lunar environment.
Communicating in space usually relies on radio waves, but NASA is exploring laser, or optical, communications, which can send data 10 to 100 times faster to the ground. Instead of radio signals, these systems use infrared light to transmit high-definition video, picture, voice, and science data across vast distances in less time. NASA has proven laser communications during previous technology demonstrations, but Artemis II will be the first crewed mission to attempt using lasers to transmit data from deep space.
To support this effort, researchers working on the agency’s Real Time Optical Receiver (RealTOR) project have developed a cost-effective laser transceiver using commercial-off-the-shelf parts. Earlier this year, NASA Glenn engineers built and tested a replica of the system at the center’s Aerospace Communications Facility, and they are now working with ANU to build a system with the same hardware models to prepare for the university’s Artemis II laser communications demo.
“Australia’s upcoming lunar experiment could showcase the capability, affordability, and reproducibility of the deep space receiver engineered by Glenn,” said Jennifer Downey, co-principal investigator for the RealTOR project at NASA Glenn. “It’s an important step in proving the feasibility of using commercial parts to develop accessible technologies for sustainable exploration beyond Earth.”
During Artemis II, which is scheduled for early 2026, NASA will fly an optical communications system aboard the Orion spacecraft, which will test using lasers to send data across the cosmos. During the mission, NASA will attempt to transmit recorded 4K ultra-high-definition video, flight procedures, pictures, science data, and voice communications from the Moon to Earth.
Nearly 10,000 miles from Cleveland, ANU researchers working at the Mount Stromlo Observatory ground station hope to receive data during Orion’s journey around the Moon using the Glenn-developed transceiver model. This ground station will serve as a test location for the new transceiver design and will not be one of the mission’s primary ground stations. If the test is successful, it will prove that commercial parts can be used to build affordable, scalable space communication systems for future missions to the Moon, Mars, and beyond.
“Engaging with The Australian National University to expand commercial laser communications offerings across the world will further demonstrate how this advanced satellite communications capability is ready to support the agency’s networks and missions as we set our sights on deep space exploration,” said Marie Piasecki, technology portfolio manager for NASA’s Space Communications and Navigation (SCaN) Program.
As NASA continues to investigate the feasibility of using commercial parts to engineer ground stations, Glenn researchers will continue to provide critical support in preparation for Australia’s demonstration.
Strong global partnerships advance technology breakthroughs and are instrumental as NASA expands humanity’s reach from the Moon to Mars, while fueling innovations that improve life on Earth. Through Artemis, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and build the foundation for the first crewed missions to Mars.
The RealTOR project is one aspect of the optical communications portfolio within NASA’s SCaN Program, which includes demonstrations and in-space experiment platforms to test the viability of infrared light for sending data to and from space. These include the LCOT (Low-Cost Optical Terminal) project, the Laser Communications Relay Demonstration, and more. NASA Glenn manages the project under the direction of agency’s SCaN Program at NASA Headquarters in Washington.
The Australian National University’s demonstration is supported by the Australian Space Agency Moon to Mars Demonstrator Mission Grant program, which has facilitated operational capability for the Australian Deep Space Optical Ground Station Network.
To learn how space communications and navigation capabilities support every agency mission, visit:
https://www.nasa.gov/communicating-with-missions
Explore More 3 min read NASA Engineers Simulate Lunar Lighting for Artemis III Moon Landing Article 1 week ago 2 min read NASA Seeks Commercial Feedback on Space Communication Solutions Article 2 weeks ago 4 min read NASA, DoD Practice Abort Scenarios Ahead of Artemis II Moon Mission Article 2 weeks agoNASA, Australia Team Up for Artemis II Lunar Laser Communications Test
As NASA prepares for its Artemis II mission, researchers at the agency’s Glenn Research Center in Cleveland are collaborating with The Australian National University (ANU) to prove inventive, cost-saving laser communications technologies in the lunar environment.
Communicating in space usually relies on radio waves, but NASA is exploring laser, or optical, communications, which can send data 10 to 100 times faster to the ground. Instead of radio signals, these systems use infrared light to transmit high-definition video, picture, voice, and science data across vast distances in less time. NASA has proven laser communications during previous technology demonstrations, but Artemis II will be the first crewed mission to attempt using lasers to transmit data from deep space.
To support this effort, researchers working on the agency’s Real Time Optical Receiver (RealTOR) project have developed a cost-effective laser transceiver using commercial-off-the-shelf parts. Earlier this year, NASA Glenn engineers built and tested a replica of the system at the center’s Aerospace Communications Facility, and they are now working with ANU to build a system with the same hardware models to prepare for the university’s Artemis II laser communications demo.
“Australia’s upcoming lunar experiment could showcase the capability, affordability, and reproducibility of the deep space receiver engineered by Glenn,” said Jennifer Downey, co-principal investigator for the RealTOR project at NASA Glenn. “It’s an important step in proving the feasibility of using commercial parts to develop accessible technologies for sustainable exploration beyond Earth.”
During Artemis II, which is scheduled for early 2026, NASA will fly an optical communications system aboard the Orion spacecraft, which will test using lasers to send data across the cosmos. During the mission, NASA will attempt to transmit recorded 4K ultra-high-definition video, flight procedures, pictures, science data, and voice communications from the Moon to Earth.
Nearly 10,000 miles from Cleveland, ANU researchers working at the Mount Stromlo Observatory ground station hope to receive data during Orion’s journey around the Moon using the Glenn-developed transceiver model. This ground station will serve as a test location for the new transceiver design and will not be one of the mission’s primary ground stations. If the test is successful, it will prove that commercial parts can be used to build affordable, scalable space communication systems for future missions to the Moon, Mars, and beyond.
“Engaging with The Australian National University to expand commercial laser communications offerings across the world will further demonstrate how this advanced satellite communications capability is ready to support the agency’s networks and missions as we set our sights on deep space exploration,” said Marie Piasecki, technology portfolio manager for NASA’s Space Communications and Navigation (SCaN) Program.
As NASA continues to investigate the feasibility of using commercial parts to engineer ground stations, Glenn researchers will continue to provide critical support in preparation for Australia’s demonstration.
Strong global partnerships advance technology breakthroughs and are instrumental as NASA expands humanity’s reach from the Moon to Mars, while fueling innovations that improve life on Earth. Through Artemis, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and build the foundation for the first crewed missions to Mars.
The RealTOR project is one aspect of the optical communications portfolio within NASA’s SCaN Program, which includes demonstrations and in-space experiment platforms to test the viability of infrared light for sending data to and from space. These include the LCOT (Low-Cost Optical Terminal) project, the Laser Communications Relay Demonstration, and more. NASA Glenn manages the project under the direction of agency’s SCaN Program at NASA Headquarters in Washington.
The Australian National University’s demonstration is supported by the Australian Space Agency Moon to Mars Demonstrator Mission Grant program, which has facilitated operational capability for the Australian Deep Space Optical Ground Station Network.
To learn how space communications and navigation capabilities support every agency mission, visit:
https://www.nasa.gov/communicating-with-missions
Explore More 3 min read NASA Engineers Simulate Lunar Lighting for Artemis III Moon Landing Article 1 week ago 2 min read NASA Seeks Commercial Feedback on Space Communication Solutions Article 1 week ago 4 min read NASA, DoD Practice Abort Scenarios Ahead of Artemis II Moon Mission Article 2 weeks agoNew Theory Explains Why So Many Exoplanets Crowd Close to Their Stars
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