A New Panorama of Our Galactic Center: Magnetized Threads Weave Spectacular Galactic Tapestry!

A new panorama from NASA’s Chandra X-ray Observatory and the MeerKAT radio telescope provides a stunning view of the center of our Milky Way galaxy. It also reveals threads of superheated gas and magnetic fields, which are weaving a tapestry of energy near the supermassive black hole that resides there.

The central part of the galaxy (left) and the same image labeled (right). Filaments are in red rectangles, purple circles are star clusters and gas clouds, green circles are dense dust clumps reflecting X-rays, and the central supermassive black hole marking the exact galactic center Sgr A* is arrowed. Credit: X-ray: NASA/CXC/UMass/Q.D. Wang; Radio: NRF/SARAO/MeerKAT.

Over the course of its mission, Chandra has taken many observations of the Galactic Center. This latest expands Chandra’s high-energy view farther above and below the plane of the galaxy — that is, the disk where most of the galaxy’s stars reside — than previous imaging campaigns. In the image, we see X-rays with different energies from Chandra in different colors. These have been combined with radio data from MeerKAT, a radio telescope in South Africa.

The result is intricate to the eye and also contains a wealth of scientific information to explore. For example, researchers identified long and narrow bands of X-rays that they call “threads”. These features are bound together by thin strips of magnetic fields. One of these threads points perpendicular to the plane of the galaxy and is about 20 light-years long but only one-hundredth that size in width. (That’s about five times the distance between the Sun and the nearest star.) These threads may have formed when magnetic fields aligned in different directions, collided, and became twisted around each other in a process called magnetic reconnection. This is similar to the phenomenon that drives energetic particles away from the Sun and is responsible for the space weather that sometimes affects Earth.

X-ray (pink) & Radio (blue) Image of G0.17-0.41. This thread is highlighted with a red box in the above image.

A detailed study of these threads teaches us more about the galactic space weather astronomers have witnessed throughout the region. This weather is driven by volatile phenomena such as supernova explosions, close-quartered stars blowing off hot gas, and outbursts of matter from regions near Sagittarius A*, our galaxy’s supermassive black hole.

In addition to the threads, the new panorama reveals other wonders in the Galactic Center. Researchers report large plumes of hot gas, which extend for about 700 light-years above and below the plane of the galaxy, seen here in greater detail than ever before. These plumes may represent galactic-scale outflows, analogous to the particles driven away from the Sun but on a much larger scale. The gas is likely heated by supernova explosions and many recent magnetic reconnections occurring near the center of the galaxy.

This new high-energy tapestry is a reminder how complex and compelling our Galaxy is. The paper by Q. Daniel Wang of the University of Massachusetts describing these results appears in the June issue of the Monthly Notices of the Royal Astronomical Society, and a preprint is available online. Source: chandra.harvard.edu.