What does "BALs" mean?
Table of Contents
Broad Absorption Lines, or BALs, are features seen in the light from some quasars. Quasars are very bright and distant objects in the universe, thought to be powered by supermassive black holes. As light travels from a quasar to us, it can pass through gas around it. This gas can absorb certain wavelengths of light, creating dark lines in the spectrum. These dark lines are what we call "absorption lines."
Why Are BALs Important?
BALs help scientists learn more about the gas surrounding quasars and how it interacts with the quasar's light. They indicate that there is a significant amount of fast-moving gas around the quasar. This gas can contain elements like carbon and magnesium, which are crucial for understanding the quasar's environment and the processes happening there.
The Connection to Quasars
Not all quasars have BALs. Those that do are often described as being "red," meaning their light has a longer wavelength. Research has shown that quasars with BALs tend to be less "radio loud," which means they do not emit as much radio wave energy compared to other quasars. This difference can affect how we see and study these objects, leading to different conclusions about their nature.
Why Study BALs?
Studying BALs reveals a lot about the characteristics of quasars and the gases surrounding them. By understanding this connection, scientists can better grasp the role of quasars in the universe and how they evolve over time. The insights gained from researching BALs also point to broader questions about the universe, such as the formation of galaxies and the behavior of matter in extreme conditions.