Left: An image of the Sagittarius B region in the Galactic center taken by SOFIA FORCAST combined with Herschel and Spitzer. Right: Ionized carbon intensity contours of the Sagittarius B region. The striped pattern is a scanning artifact due to the motion of the telescope. In both panels, crosses indicate the locations of the three star-forming cores of Sagittarius B2. Credit: Left: NASA/SOFIA/JPL-Caltech/ESA/Herschel; Right: Harris et al., 2021
Columbia, MD. The Stratospheric Observatory for Infrared Astronomy, SOFIA, imaged the ionized carbon characteristics of Sagittarius B (Sgr B), a molecular cloud of gas and dust in the center of the Milky Way. Studying the ionized carbon emission from Sagittarius B provides critical information about star formation in our own galaxy and beyond. In particular, observing the concentration of ionized carbon in a molecular cloud like Sgr B is a powerful method for probing the properties of the system, including its level of star formation.
Using SOFIA’s upgraded German Receiver for Astronomy at Terahertz Frequencies (upGREAT), a team of researchers imaged the ionized carbon characteristics of Sgr B. GREAT has ample spectral resolution to study Sgr B in detail at scales ranging from small clouds to star formation regions, allowing the scientists to understand the dynamics of gas within our Galactic Center. UpGREAT’s rapid imaging capabilities and detailed velocity resolution were crucial for enabling the study, which is part of a much larger scan of the area.
Among a number of findings, astronomers noted the steady carbon emission from Sgr B implies the entire region is physically connected, making it one continuous structure spanning about 34 by 15 parsecs, or about 111 by 49 light-years. It is spatially complex, comprised of arcs and ridges undergoing large-scale, turbulent motion.
By comparing the brightness of different emission lines, the group obtained an estimate of the ratio of ionized carbon emission coming from regions dominated by ionized hydrogen compared to emission from photodissociation regions, areas heated by far-infrared radiation dominated by atomic and molecular hydrogen. They found about half of the emission in the system is coming from each of these types of environments.
Notably, the three star-forming cores of Sagittarius B2, within Sgr B, exhibit no ionized carbon emission, which is atypical of extreme star forming regions. They appear to be within a dark, narrow lane of dust which appears to be slightly physically distanced and in front of the rest of the region – though they remain, for the most part, dynamically related. This may answer the debate about the origin of star formation in Sgr B — dark dust lanes have been associated with cloud-cloud collisions and are a common sign of a shock-induced star formation trigger. This possibility is also consistent with the fact that multiple different star formation stages coexist within Sgr B, as a recent burst of star formation within Sgr B indicates some sort of trigger has likely occurred.
“The nuclear regions of galaxies are fascinating places, and our relatively nearby Galactic center lets us explore its gas clouds, stars, and black hole in far more detail than we can get in any other galaxy,” said Andrew Harris, astronomer at the University of Maryland and lead author on the upcoming paper. “The SOFIA results we found in our US-German project join those made at wavelengths across the electromagnetic spectrum made from telescopes all over the world and in space, allowing us to better understand not only our Galaxy but others as well.”
Source: USRA/Newsroom
About SOFIA
Using SOFIA’s upgraded German Receiver for Astronomy at Terahertz Frequencies (upGREAT), a team of researchers imaged the ionized carbon characteristics of Sgr B. GREAT has ample spectral resolution to study Sgr B in detail at scales ranging from small clouds to star formation regions, allowing the scientists to understand the dynamics of gas within our Galactic Center. UpGREAT’s rapid imaging capabilities and detailed velocity resolution were crucial for enabling the study, which is part of a much larger scan of the area.
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
Contact:
Suraiya Farukhi, Ph.D.
Director, External
Communications
sfarukhi@usra.edu
443-812-6945
Contact:
Suraiya Farukhi, Ph.D.
Director, External
Communications
sfarukhi@usra.edu
443-812-6945
Source: USRA/Newsroom
