Jets

Definition

Jets are narrow streams of gas and particles that are ejected from protostars at high velocities, often perpendicular to the plane of the surrounding accretion disk. These outflows play a crucial role in the formation and evolution of protostellar objects by influencing their environment, regulating mass accretion, and contributing to chemical processes in the surrounding molecular clouds.

5 Must Know Facts For Your Next Test

1. Jets can reach speeds of several hundred kilometers per second and can extend for light-years into space.
2. The material in jets is often composed of ionized gas, such as hydrogen and helium, and may also carry traces of complex molecules formed in the protostar's environment.
3. The presence of jets indicates ongoing star formation processes, as they are typically associated with young stellar objects actively accreting material.
4. Jets help to clear out surrounding material, preventing excessive mass accumulation onto the protostar, which can affect its growth and stability.
5. The study of jets provides insights into the physical conditions in the vicinity of forming stars and helps astronomers understand the mechanisms behind star formation.

Review Questions

• How do jets influence the surrounding environment of a protostar during its formation?
  • Jets significantly influence the environment around a protostar by ejecting material at high velocities, which clears away surrounding gas and dust. This clearing action prevents excessive mass from accumulating onto the protostar, allowing it to grow steadily while regulating its accretion rate. Additionally, jets can shape nearby molecular clouds by compressing material and triggering new star formation in regions affected by the outflows.
• Discuss the relationship between jets and accretion disks in the context of protostellar development.
  • Jets are closely linked to accretion disks as they originate from the inner regions of these disks. As material spirals inward toward the protostar from the accretion disk, some of it is funneled along magnetic field lines that extend outward, forming jets that shoot away from the disk. This process not only facilitates efficient mass transfer to the growing star but also helps maintain balance within the system by removing excess angular momentum.
• Evaluate how studying jets contributes to our understanding of chemical processes during star formation.
  • Studying jets enhances our understanding of chemical processes during star formation by revealing how these outflows transport materials from the protostar's environment into space. Jets can carry complex molecules and elements that were formed under unique conditions in the molecular cloud. By analyzing the composition of these jets, scientists can gather valuable information about the chemical evolution occurring during star formation and how these processes impact the development of planetary systems.

Related terms

Accretion Disk: A rotating disk of gas and dust formed around a protostar, where material gradually spirals inward, providing mass to the star.

Molecular Cloud: A dense region of gas and dust in space, rich in molecules, where stars are born and protostars develop.

Outflow: The general term for any flow of gas away from a star or protostar, which can include both jets and broader winds.