Examining the ionized carbon emissions of Sagittarius B provides essential information about star formation in our own galaxy and beyond.
Sagittarius, or Sgr B, a cloud of gas and dust near the center of the Milky Way is one of the brightest sources in the Central Molecular Zone – a massive, dense area of gas at the center of our galaxy, home to very high star formation rates and turbulent molecular gas clouds. Less than 27,000 light years away, Sgr B is a relatively close neighbor, making it a useful region to study, both as an indicator for understanding other galaxies in the universe and also for understanding our own galactic center. .
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 SOFIAThe German Receiver Improved for Astronomy at Terahertz Frequencies, or upGREAT, a team of researchers has imaged the characteristics of the ionized carbon of Sgr B. GREAT has sufficient spectral resolution to study Sgr B in detail at scales ranging from small clouds To star-forming regions, allowing scientists to understand gas dynamics within our galactic center. UpGREAT’s fast imaging capabilities and detailed speed resolution were crucial to enable the study, which is part of a much larger scan of the area.
Among a number of discoveries, astronomers have noted that the constant emission of carbon from Sgr B implies that the entire region is physically connected, making it a continuous structure spanning about 34 by 15 parsecs, or about 111 by 49 years. -light. It is spatially complex, composed of arcs and ridges subjected to large-scale turbulent motion.
By comparing the brightness of different emission lines, the group obtained an estimate of the ratio of emission of ionized carbon from regions dominated by ionized hydrogen versus emission from photodissociation regions, which are created by distant UV photons of massive stars.
In particular, the three star formation cores of Sagittarius B2, within Sgr B, do not exhibit any emission of ionized carbon, which is atypical of extreme star formation regions. They appear to be in a dark, narrow strip of dust that appears to be physically slightly apart and ahead of the rest of the region – although they remain, for the most part, dynamically linked. This may answer the debate about the origin of star formation in Sgr B – bands of dark dust have been associated with cloud-to-cloud collisions and are a common sign of a star formation trigger induced by a shock. This possibility is also consistent with the fact that several stages of star formation coexist in Sgr B, as a recent explosion of star formation in Sgr B indicates that some sort of trigger has likely occurred.
“The nuclear regions of galaxies are fascinating places, and our relatively close galactic center allows us to explore its gas clouds, stars and black hole in much more detail than we can get in any other galaxy, ”said Andrew Harris, University of Maryland astronomer and lead author of the article. “The SOFIA results we found in our US-German project join those obtained at wavelengths across the electromagnetic spectrum made from telescopes around the world and in space, allowing us to better understand not only our galaxy but also others. “
SOFIA is a joint project of ">Nasa and the German Space Agency at DLR. The DLR provides the telescope, scheduled aircraft maintenance and other support for the mission. NASA’s Ames Research Center in Silicon Valley, California manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German Institute SOFIA of the University of Stuttgart. The aircraft is maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California.