A groundbreaking study has produced the first 3D maps of molecular clouds in the heart of the Milky Way, offering new insights into star formation in one of the most extreme environments of our galaxy. Researchers utilized decades of data from a variety of telescopes, including the Submillimeter Array, the Herschel Space Telescope, the Spitzer Space Telescope, and NASA’s Chandra X-ray Observatory, to map these clouds in three dimensions.
These molecular clouds, where new stars are born, lie near Sagittarius A* (Sgr A*), the Milky Way's supermassive black hole. The center of the galaxy is a turbulent region with gas densities and temperatures significantly higher than the rest of the galaxy, making it a challenging environment for study. In this region, inflowing gas occasionally gets drawn into Sgr A*, where it emits powerful X-ray flares that travel outward and interact with surrounding molecular clouds.
Using a novel X-ray tomography technique, the researchers were able to generate 3D models of two specific molecular clouds—the "Stone" and the "Sticks" clouds. This approach differs from traditional imaging methods that capture only two spatial dimensions. By analyzing the X-ray data collected over two decades by Chandra, the team could measure the third dimension, allowing them to observe how these clouds are illuminated over time as the X-rays interact with the gas.
In addition to the X-ray data, the researchers incorporated submillimeter and infrared observations to compare the structures seen in different wavelengths. Notably, they found that some cloud structures visible in submillimeter wavelengths were not detected in X-rays, providing valuable clues about the duration of the X-ray flares. The team concluded that the X-ray flare that illuminated the Stone Cloud lasted no longer than four to five months.
The findings were presented by Danya Alboslani from the University of Connecticut at the 245th meeting of the American Astronomical Society in National Harbor, MD. The full study, detailing these innovative 3D molecular cloud models, is available in a recent publication. The Chandra program, managed by NASA’s Marshall Space Flight Center, was integral to the success of this research, with science operations overseen by the Smithsonian Astrophysical Observatory's Chandra X-ray Center.
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