For the first time, astronomers have detected a moving red light streak heading toward Earth, potentially revealing the energy source at the center of the Milky Way galaxy.
A research team at Embry-Riddle Aeronautical University in Florida, USA, utilized the Wisconsin H-Alpha Mapper (WHAM) telescope in Chile to detect red light emanating from an area known as the “Inclined Disk” located in the central region of the Milky Way. This faint light, which can only be observed from Earth, penetrates through dust holes and is a trace of ionized hydrogen gas coming from forming stars.
Simulation of the bright red streak in the center of the Milky Way. (Video: Science Advances).
Researchers stated that the red light was discovered by comparing various bands of visible light emitted from ionized nitrogen and oxygen gases. According to Dr. Lawrence Haffner, a co-author of the study, without an energy source, free electrons would find each other and recombine to return to a neutral state. This typically occurs over a relatively short period.
Professor Bob Benjamin, a colleague of Lawrence Haffner at the University of Wisconsin-Whitewater, observed the light streak resembling a “red flag” after two decades of reviewing WHAM data. Its unusual shape stands out in the dark, dust-laden central region of the Milky Way. The light streak is moving toward Earth and cannot be explained by known physical phenomena such as galactic rotation.
The red light streak is moving toward Earth.
Lead researcher Dhanesh Krishnarao, a doctoral student at the University of Wisconsin-Madison, leveraged a current model to predict how much gas is present. Unprocessed data from the WHAM telescope enabled him to refine calculations until the research team developed an accurate 3D picture of the light streak’s structure. They published their findings on July 3 in the journal Science Advances. The data suggests that about half of the hydrogen gas is ionized by an unknown source.
Identifying and measuring the ionized gas allows astronomers to compare the center of the Milky Way with other spiral galaxies more easily. The next step is to investigate the energy source responsible for the ionization process at the galactic center.
