The Stratospheric Observatory for Infrared Astronomy (SOFIA) Enabling Major Scientific Discoveries

Columbia, MD—October 7, 2021. During the past year, NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) has enabled several outstanding and unique scientific discoveries in astronomy, astrophysics, planetary science, and earth science -- from observing the Solar System, to observing galactic and extragalactic centers, star formation and supernovae. SOFIA, whose science mission operations are managed by Universities Space Research Association (USRA) “continues to make significant contributions and its seminal findings have been published in high impact refereed scientific journals,” said Margaret Meixner, USRA Director of SOFIA Mission Operations.

SOFIA is regarded as a world-class observatory committed to improving scientific prowess and looks forward to continuing collaborations with other major ground-based and space-based astronomical observatories such as ALMA and JWST in the future. SOFIA researchers continue to lead and co-author many highly influential refereed papers, with some of these papers being led by SOFIA scientists as the first author, and most being led by scientists world-wide.

Supported by NASA and DLR—the German Space Center—some of SOFIA’s significant discoveriesduring this past year are highlighted below.

SOFIA discovers water on the Moon

Clavius Still; Image credit: NASA/Moon Trek/U.S. Geological Survey/Lunar Reconnaissance Orbiter

SOFIA recently discovered even more compelling evidence of water on the Moon, this time in its sunlit regions—in Clavius Crater-- affording exciting new opportunities for lunar science.

This discovery enhances our understanding of the behavior of water and other volatile elements on the surface of cold, airless bodies. This important result and follow-up observations by SOFIA will support future Moon missions in creating the first water resource maps of the Moon and was published in Nature Astronomy, October 2020.

Growth of active black holes does not stop star birth—SOFIA findings causing scientists to rethink galactic evolution

Illustration of the galaxy called CQ4479. The extremely active black hole at the galaxy’s center is consuming material so fast that the material is glowing as it spins into the black hole’s center, forming a luminous quasar. Quasars create intense energy that was thought to halt all star birth and drive a lethal blow to a galaxy’s growth. But SOFIA found that the galaxy CQ4479 is surviving these monstrous forces, holding on to enough cold gas, shown around the edges in brown, to birth about 100 Sun-sized stars a year, shown in blue. The discovery is causing scientists to re-think their theories of galactic evolution. Credit: NASA/ Daniel Rutter

Black holes are thought to gobble up so much surrounding material that they put an end to the life of their host galaxy. In that process they create a highly energetic object called a quasar which was previously thought to halt star birth. Now researchers, using SOFIA, have found a galaxy –CQ4479--that is surviving the ravenous forces, and continuing to birth new stars –about 100 Sun-sized stars a year. >The discovery is causing scientists to re-think their theories of galactic evolution. The results are published in the Astrophysical Journal, November 2020

Galactic wind flowing from the center of the Cigar Galaxy (M82) channels gas and dust along a magnetic field providing clues to the evolution of galaxies

Magnetic fields in Messier 82, or the Cigar galaxy, are shown as lines over a visible light and infrared composite image of the galaxy from the Hubble Space Telescope and the Spitzer Space Telescope. Stellar winds streaming from hot new stars form a galactic super wind that is blasting out plumes of hot gas (red) and a huge halo of smoky dust (yellow/orange) perpendicular to the narrow galaxy (white). Researchers used the Stratospheric Observatory for Infrared Astronomy magnetic field data and tools that have been used extensively to study the physics around the Sun to extrapolate the magnetic field’s strength 20,000 lights-years around the galaxy. They appear to extend indefinitely into intergalactic space, like the Sun’s solar wind, and may help explain how the gas and dust have traveled so far away from the galaxy Credit: NASA, SOFIA, L. Proudfit; NASA, ESA, Hubble Heritage Team; NASA, JPL-Caltech, C. Engelbracht

New research shows that magnetic fields are also contributing to the expulsion of material from Messier 82, a well-known example of a starburst galaxy with a distinctive, elongated shape.

The findings from, SOFIA, help explain how dust and gas can move from inside galaxies into intergalactic space, offering clues to how galaxies formed. This material is enriched with elements like carbon and oxygen that support life and are the building blocks for future galaxies and stars. The research was presented at the meeting of the 2021 Winter meeting of the American Astronomical Society and has been published in the Astrophysical Journal, June 2021.

SOFIA’s studies of comet Catalina suggests comets delivered carbon to rocky planets

Illustration of a comet from the Oort Cloud as it passes through the solar system with dust and gas evaporating into its tail. SOFIA’s observations of Comet Catalina reveal that it’s carbon-rich, suggesting that comets delivered carbon to the terrestrial planets like Earth and Mars as they formed in the early solar system. Credit: NASA/SOFIA/ Lynette Cook

SOFIA discovered that some comets are carbon rich and may be the source of carbon on planets like Earth and Mars. The observations of Comet Catalina as it made its first pass through the solar system and was briefly visible to stargazers, offers new clues about how this essential ingredient for life came to rocky planets in the Sun’s inhabitable zone.

Comets like Catalina could have been an essential source of carbon on planets like Earth and Mars during the early formation of the solar system. New results from SOFIA, a joint project of NASA and the German Aerospace Center, were published recently in the Planetary Science Journal, February 2021.

SOFIA’s observations of the Whirlpool galaxy (M51) identify cause of Spiral arms in the galaxy

Magnetic field streamlines detected by SOFIA are shown over an image of the Whirlpool galaxy, M51, from NASA’s Hubble Space Telescope. For the first time, SOFIA’s infrared view shows that the magnetic fields in the outer arms do not follow the galaxy's spiral shape and are instead distorted. The intense star formation activity in theses regions, shown in red, may be causing the chaos, along with the forces from neighboring galaxy, NGC 5195, tugging on one of the spiral arms. Credit: NASA, the SOFIA science team, A. Borlaff; NASA, ESA, S. Beckwith (STScI) and the Hubble Heritage Team (STScI/AURA)

The Whirlpool galaxy’s arms are strikingly visible as they reach out along the central spine structure displaying swirling clouds of gas and dust are massive star-making factories. But new observations by NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, presented at 237^th meeting of the American Astronomical Society, and accepted for publication in the Astrophysical Journal shows a more complicated picture --that magnetic fields play an important role in shaping spiral galaxies.

Radio telescopes previously detected neatly-drawn magnetic fields throughout the length of the galaxy’s massive arms. But under SOFIA’s infrared gaze for the first time those lines give way to a chaotic scene in the outer spiral arms. Using a far-infrared camera and imaging polarimeter instrument called the High-Resolution Airborne Wideband Camera, or HAWC+, researchers found that the magnetic fields in the outskirts of the galaxy no longer follow the spiral structure and are instead distorted. The research builds on SOFIA’s previous findings that show magnetic fields are important in shaping spiral galaxies and helps unravel the complex role magnetic fields play in the evolution of galaxies.

SOFIA offers new way to study Earth’s atmosphere

Photo taken through SOFIA’s window during an observing flight from New Zealand. Aurora glow green high in Earth’s atmosphere in a region called the thermosphere. The Milky Way (left) and Mars (right) shine brightly above it. Credit: NASA/SOFIA/Ian Griffin

A major science finding that resulted from SOFIA’s direct measurement of atomic oxygen in the mesosphere and lower thermosphere, offered a new way to study one of the least understood regions of Earth’s upper atmosphere. The results were published in Nature Communications Earth and Environment, January, 2021.

SOFIA observed a particular form of unbonded oxygen, known as atomic oxygen, which is distinct from the life-giving O₂ found at the Earth’s surface. Atomic oxygen plays an important role in cooling the upper atmosphere and therefore is used to estimate temperatures in this region. Climate models predict that increasing greenhouse gases will raise temperatures in the lower atmosphere but decrease temperatures in the mesosphere. A more accurate monitoring of the mesosphere’s temperature can help researchers better understand the relationship between the lower and upper atmosphere. SOFIA’s direct measurements improve these temperature estimates.

SOFIA witnesses rare accretion flare on a massive protostar

The Cat's Paw Nebula (NGC 6334), imaged here by NASA's Spitzer Space Telescope using the IRAC instrument, is a star-forming region of the Milky Way galaxy. The dark filament running through the middle of the nebula is a particularly dense region of gas and dust. The inset shows the region of the high-mass protostar with pre- and post-outburst luminosity imaged by the Cerro Tololo Inter-American Observatory and NASA’s Stratospheric Observatory for Infrared Astronomy, respectively. Credits: Cat’s Paw Nebula: NASA/JPL-Caltech; Left inset: De Buizer et al. 2000; Right inset: Hunter et al. 2021

SOFIA can detect extraordinary luminous outbursts due to episodic accretion into stellar objects at different stages of their evolution. Recently, SOFIA observed a rare accretion flare on a massive protostar. Infrared data obtained by SOFIA was crucial for studying an outburst from a massive protostar in the iconic Cat’s Paw Nebula that is now glowing at 50,000 times the luminosity of the Sun. Unlike some of its companions, this particular protostar is so deeply embedded that it was not even detectable in the infrared prior to the outburst. These new findings confirm that the formation of high-mass stars can be considered a scaled-up version of the process by which low-mass stars like our Sun are born. The results are published in the Astrophysical Journal Letters, May 2021.

SOFIA finds clues to star formation in a young nebula

Composite image of the nebula RCW 120. The ring-shaped clouds around the nebula were detected by the Spitzer Space Telescope. SOFIA measured the glowing gas shown in red and blue to study the nebula’s expansion speed and determine its age. The blue gas represents gas expanding in the direction toward Earth and the red away from Earth. The expansion is triggering the birth of stellar neighbors at breakneck speeds – and revealing the nebula is younger than previously believed. Credit: NASA/JPL-Caltech/SOFIA

Astronomers are still trying to understand how stars and galaxies formed in the early universe. Using SOFIA, scientists have new data from a glowing nebula, filled with clouds of hot gas and dust, known as RCW 120. Observations from SOFIA suggest that this nebula may be representative of how stars formed in the early universe. Scientists found the stellar wind emanating from the nebula's central massive star is making the nebula expand rapidly. The expansion is triggering the birth of stellar neighbors at breakneck speeds – and revealing the nebula is younger than previously believed. The results are published in Science Advances, April 2021.

Galactic merger warps magnetic fields

Composite image of Centaurus A. Magnetic fields observed by SOFIA are shown as streamlines over an image of the galaxy taken at visible and submillimeter wavelengths by the European Southern Observatory and Atacama Pathfinder Experiment (orange), X-ray wavelengths from the Chandra X-Ray observatory (blue) and infrared from the Spitzer Space Telescope (dark red). The large-scale magnetic fields, across 1,600 light-years, are parallel to the dust lanes seen in visible light and other wavelengths. However, the fields appear twisted and distorted near the middle. The twisting is a remnant of the spiral-shaped magnetic field from one of the original galaxies, while the active, supermassive black hole at its core adds to the distortions. Image Credits: Optical: European Southern Observatory (ESO) Wide Field Imager Submillimeter: Max Planck Institute for Radio Astronomy/ESO/Atacama Pathfinder Experiment (APEX)/A.Weiss et al X-ray and Infrared: NASA/Chandra/R. Kraft; JPL-Caltech/J. Keene; SOFIA/L. Proudfit

SOFIA’s new observations provide new insights into how the early universe may have been shaped by galactic mergers under the influence of their supercharged magnetic fields and were recently published in Nature Astronomy, June 2021.

For the first time, scientists have mapped out the invisible magnetic fields pulsing through Centaurus A using infrared light. The results show how the merging of the two original galaxies created a new, reshaped, and contorted galaxy that not only combined the two galaxies’ magnetic fields but amplified their forces. One of the brightest galaxies in the night sky, Centaurus A, is well known for its distinct “S” shape, and according to scientists is a good candidate for the study of galactic mergers.

SOFIA Probes Heart of Hot core chemistry increasing understanding of star formation

The image shows the Orion region taken by the Gemini South Telescope. The cross marks the approximate position of the Orion hot core located at the center of an explosion generated by a multibody dynamical encounter about 500 years ago. The red and blue nebulosity trace finger-like tendrils resulting from the blast. The SOFIA EXES spectrum across the bottom of the image shows the signature of the HNC molecule – the series of intensity dips near 21.6µm.

SOFIA probed the Heart of Hot Core Chemistry High-resolution molecular line surveys provide a chemical inventory for star forming regions — essential for establishing the relative importance of potential chemical networks, understanding organic chemistry associated with star formation. SOFIA was able to detect HNC, HCN, and H¹³CN in an Orion hot core—which was not possible with previous high resolution molecular surveys. The findings were published in a paper in the Astrophysical Journal, January 2021

Discovering New Insights into Star forming regions called Westerland 2

A color image of the emissions in RCW 49, the star-forming region of Westerlund 2. Credit: Tiwari et al.

With the help of the SOFIA’s FEEDBACK program, researchers obtained the first clear picture of how massive stars begin to form. Using the German REceiver for Astronomy at Terahertz Frequencies, or GREAT, in one of its advanced configurations called UpGREAT, SOFIA’s FEEDBACK program enabled high-resolution insights into the star-forming region called Westerlund 2 - one of the brightest and most massive star formation regions in the Milky Way. The results were recently published in the Astrophysical Journal, September 2021.

“We believe the best is yet to come in the remaining years in SOFIA’s planned life-time, and perhaps beyond, based on its new and archival datasets. For example, SOFIA observations are being used in tandem with other major ground-based and space-based astronomical observatories to study our galaxy and solar system (e.g. Earth’s Moon and other planets) and galaxies far beyond,” said USRA’s Ghassem Asrar, Senior Vice President, Science.

Additional Resources:

https://www.sofia.usra.edu/science/publications/sofia-publications

https://newsroom.usra.edu

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About USRA

Founded in 1969, under the auspices of the National Academy of Sciences at the request of the U.S. Government, the Universities Space Research Association (USRA) is a nonprofit corporation chartered to advance space-related science, technology and engineering. USRA operates scientific institutes and facilities, and conducts other major research and educational programs. USRA engages the university community and employs in-house scientific leadership, innovative research and development, and project management expertise. More information about USRA is available at www.usra.edu.

About SOFIA

SOFIA is a joint project of NASA and the German Aerospace Center. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California.