Webb Reveals Intricate Webs of Gas and Dust in Nearby Galaxies :: NASANET

New images from NASA’s James Webb Space Telescope are giving scientists their first high-resolution look at the fine structure of nearby galaxies and how that is affected by the formation of young stars. NGC 1433 is a barred spiral galaxy with a particularly bright nucleus surrounded by double rings of star formation. For the first time, in Webb’s infrared images, scientists can see cavernous bubbles of gas where forming stars have released energy into their surrounding environment. Credits: NASA, ESA, CSA and J. Lee (NOIRLab). Image Processing: A. Pagan (STScI)

Researchers using NASA’s James Webb Space Telescope are observing for the first time the formation of stars, gas, and dust in nearby galaxies with unprecedented resolution at infrared wavelengths. The data has enabled an initial collection of 21 research papers that provide new insight into how some of the smallest-scale processes in our universe, the beginnings of star formation, impact the evolution of the largest objects in our cosmos: the galaxies.

The largest study of nearby galaxies in Webb’s first year of science operations is being carried out by the PHANGS collaboration, involving more than 100 researchers from around the world. The Webb observations are led by Janice Lee, chief scientist for the Gemini Observatory at the National Science Foundation’s NOIRLab and an affiliated astronomer at the University of Arizona in Tucson.

The team is studying a diverse sample of 19 spiral galaxies, and in the first few months of Webb’s science operations, observations have been made of five of those targets: M74, NGC 7496, IC 5332, NGC 1365, and NGC 1433. The results already They are astonishing astronomers.

“The clarity with which we are seeing the fine structure certainly took us by surprise,” said David Thilker, a team member at Johns Hopkins University in Baltimore, Maryland.

“We are seeing directly how the energy from the formation of young stars affects the gas around them, and it’s just remarkable,” said Erik Rosolowsky, a team member from the University of Alberta, Canada.

NGC 7496’s spiral arms are filled with cavernous bubbles and shells that overlap each other in this MIRI image. These filaments and hollow cavities are evidence of young stars releasing energy and, in some cases, expelling gas and dust from the surrounding interstellar medium. Credits: NASA, ESA, CSA, and J. Lee (NOIRLab). Image Processing: A. Pagan (STScI)

Images from the Webb Mid-Infrared Instrument (MIRI) reveal the presence of a network of highly structured features within these galaxies: glowing pockets of dust and huge cavernous bubbles of gas lining the spiral arms. In some regions of nearby observed galaxies, this network of features appears to be built from individual and overlapping layers and bubbles where young stars are releasing energy.

“Areas that are completely dark in the Hubble images light up in exquisite detail in these new infrared images, allowing us to study how dust in the interstellar medium has absorbed light from forming stars and re-emitted it. in the infrared, illuminating a complex web of gas and dust,” said team member Karin Sandstrom of the University of California, San Diego.

The high-resolution images needed to study these structures have eluded astronomers for a long time, until Webb came on the scene.

“The PHANGS team has spent years observing these galaxies at optical, radio, and ultraviolet wavelengths using NASA’s Hubble Space Telescope, the Atacama Large Millimeter/Submillimeter Array, and the Very Large Telescope’s Multi-Unit Spectroscopic Explorer.” added Adam Leroy, a member of the Ohio State University team. “But, the early stages of a star’s life cycle have remained out of sight because the process is shrouded in clouds of gas and dust.”

Webb’s powerful infrared capabilities can cut through dust to connect the missing puzzle pieces.

For example, the specific wavelengths observable by MIRI (7.7 and 11.3 microns) and Webb’s near-infrared camera (3.3 microns) are sensitive to the emission of polycyclic aromatic hydrocarbons, which play a critical role. in the formation of stars and planets. These molecules were detected by Webb in the first observations of the PHANGS program.

Studying these interactions at the finest scale can help provide insight into the big picture of how galaxies have evolved over time.

In MIRI observations of NGC 1365, clumps of dust and gas in the interstellar medium have absorbed light from forming stars and emitted it back in the infrared, illuminating an intricate network of cavernous bubbles and filamentary layers influenced by by young stars releasing energy in the spiral arms of the galaxy. Credits: NASA, ESA, CSA, and J. Lee (NOIRLab). Image Processing: A. Pagan (STScI)

“Because these observations are taken as part of what is called a treasury program, they are available to the public as they are observed and received on Earth,” said Eva Schinnerer of the Max Planck Institute for Astronomy in Heidelberg, Germany. , and leader of the PHANGS Collaboration.

The PHANGS team will work to create and publish data sets that align the Webb data with each of the previously obtained complementary data sets from the other observatories, to help speed discovery by the broader astronomical community.

“Thanks to the telescope’s resolution, for the first time we can perform a complete census of star formation and make inventories of interstellar intermediate bubble structures in nearby galaxies beyond the Local Group,” Lee said. “That census will help us understand how star formation and feedback imprints itself in the interstellar medium, giving rise to the next generation of stars, or preventing the next generation of stars from forming.”