. | . |
Simulated Image Shows How NASA's Roman Could Expand on Hubble's Deepest View by Ashley Balzer for GSFC News Greenbelt MD (SPX) Jan 11, 2022
A team of astrophysicists has created a simulated image that shows how the Nancy Grace Roman Space Telescope could conduct a mega-exposure similar to but far larger than Hubble's celebrated Ultra Deep Field Image. This Hubble observation transformed our view of the early universe, revealing galaxies that formed just a few hundred million years after the big bang. "Roman has the unique ability to image very large areas of the sky, which allows us to see the environments around galaxies in the early universe," said Nicole Drakos, a postdoctoral scholar at the University of California Santa Cruz, who led the study. "Our study helps demonstrate what a Roman ultra-deep field could tell us about the universe, while providing a tool for the scientific community to extract the most value from such a program." By capturing the Hubble Ultra Deep Field image, astronomers pulled aside the cosmic curtains to reveal that a tiny, seemingly empty slice of the sky was actually teeming with thousands of galaxies, each containing billions of stars. The Hubble team harnessed the power of a long exposure time - hundreds of hours between 2002 and 2012 - which allowed the telescope to collect more light than it could in a single, short observation. The resulting image helped us see more than 13 billion years back in time. Hubble's Ultra Deep Field offers an incredible window to the early universe, but an extremely narrow one, covering less than one ten millionth of the whole sky. The new simulation showcases Roman's power to perform a similar observation on a much larger scale, revealing millions of galaxies instead of thousands. While a Roman ultra-deep field would be just as sharp as Hubble's and peer equally far back in time, it could reveal an area 300 times larger, offering a much broader view of cosmic ecosystems. "The Hubble Ultra Deep Field gave us a glimpse of the universe's youth, but it was too small to reveal much information about what the cosmos was really like back then as a whole," said Brant Robertson, an astronomy professor at the University of California Santa Cruz and a co-author of the study. "It's like looking at a single piece of a 10,000-piece puzzle. Roman could give us 100 connected puzzle pieces, offering a much better picture of what the early universe was like and opening up new scientific opportunities." To generate their simulated Roman ultra-deep field image, Drakos and co-authors created a synthetic catalog of galaxies, complete with detailed information about each one. By doing so, the team essentially created a mock universe, basing their synthetic galaxies on dark matter simulations and observation-based models. They made the galaxy catalog publicly available so other scientists can use it to prepare for future Roman observations. The team also created an interactive website where users can zoom and pan across the full-resolution image. The team's results will be published in The Astrophysical Journal.
Looking far and wide Drakos and co-authors show that a Roman ultra-deep field program could reveal more than a million galaxies scattered throughout cosmic history, from very young and small galaxies just beginning to form stars to the modern era, which features many massive, often relatively inactive galaxies. Scientists would be able to probe how galaxies transition from forming lots of new stars to this quieter stage, when star formation is complete. The possible causes of this metamorphosis are currently poorly understood, but Roman's wide viewing power could offer clues about how a galaxy's environment, such as its location in relation to other galaxies or galaxy clusters, affects its star formation. Galaxies in which star formation has ended, known as quiescent galaxies, are increasingly difficult to find the farther back in time astronomers look. "We're not sure whether we haven't detected very distant quiescent galaxies because they don't exist, or simply because they're so difficult to find," Drakos said. Drakos and co-authors showed that Roman's ability to image large patches of the distant universe and reveal both rare and faint objects could help astronomers find as many as 100,000 quiescent galaxies, likely including some of the farthest ones ever discovered. Astronomers could also use Roman ultra-deep field observations to determine whether galaxies transition from star-forming to quiescent differently in different cosmic eras.
The end of the cosmic "dark ages" But then the neutral hydrogen atoms broke apart, returning to charged particles in an epoch of reionization. The fog lifted, transforming the universe from being mostly opaque to the brilliant starscape we see today. Findings from NASA's Spitzer Space Telescope hint that the first galaxies released extremely high amounts of ionizing radiation - ultraviolet light, X-rays, and gamma rays - which could have disrupted the hydrogen fog. A Roman ultra-deep field program could advance our understanding of the epoch of reionization by revealing wide images containing more than 10,000 galaxies from this relatively brief cosmic age, which happened sometime between when the universe was around 600 million to 900 million years old, and a detailed view of the environments around these galaxies. This could help scientists understand what caused reionization, when exactly it happened, and whether its occurrence was uniform or patchy. Roman also has the power to reveal how galaxies and galaxy clusters - which form some of the largest structures in the universe - evolved over time. Scientists think galaxies were born within vast spherical clumps of dark matter called halos. Observations indicate that each galaxy's luminosity, or absolute brightness, is linked to the mass of the dark matter halo it resides in. By creating an ultra-deep field image, Roman could help astronomers better understand this connection. This has implications for not only galaxy formation but also the standard cosmological model - the theoretical model of how the universe evolves - which includes a dark matter clumping parameter. "Roman could shine a light on so many cosmic mysteries in just a few hundred hours of observing time," said Bruno Villasenor, a graduate student at the University of California Santa Cruz and a co-author of the study. "It's amazing to think that no one knew for sure whether other galaxies existed until about a hundred years ago. Now, Roman offers us the opportunity to observe thousands of the first galaxies that appeared in the very early universe!"
NASA to host coverage for Webb Telescope's final unfolding Washington DC (SPX) Jan 07, 2022 NASA will provide live coverage and host a media briefing Saturday, Jan. 8, for the conclusion of the James Webb Space Telescope's major spacecraft deployments. Beginning no earlier than 9 a.m. EST, NASA will air live coverage of the final hours of Webb's major deployments. After the live broadcast concludes, at approximately 1:30 p.m., NASA will hold a media briefing. Both the broadcast and media briefing will air live on NASA TV, the NASA app, and the agency's website. As the final step in the o ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |