Quenching of star formation

Definition

Quenching of star formation refers to the process that leads to a significant decrease or complete halt in the formation of new stars in galaxies. This phenomenon is crucial for understanding galaxy evolution, as it impacts the growth, structure, and eventual fate of galaxies. Quenching can result from various mechanisms, including feedback processes from supernovae, active galactic nuclei, or environmental effects such as galaxy mergers and interactions.

5 Must Know Facts For Your Next Test

1. Quenching can occur due to internal processes within a galaxy, such as feedback from massive stars and supernovae that blow away gas necessary for new star formation.
2. Environmental effects like galaxy mergers can trigger quenching by stripping gas from galaxies or altering their dynamics, which can inhibit star formation.
3. Quenching often leads to the transformation of a galaxy from a blue, star-forming state to a red, quiescent state, affecting its color and spectral properties.
4. Understanding quenching is essential for studying galaxy evolution over cosmic time and contributes to models of how galaxies transition between different phases.
5. The degree and mechanism of quenching can vary widely among galaxies, influencing their ultimate fate and their role in the larger cosmic web.

Review Questions

• How does feedback from supernovae contribute to the quenching of star formation in galaxies?
  • Feedback from supernovae plays a critical role in quenching star formation by injecting energy into the surrounding interstellar medium. This energy can heat up or expel the gas necessary for forming new stars, effectively halting the star formation process. As massive stars explode at the end of their life cycle, they create shock waves that can disperse gas and dust, preventing further stellar birth in their vicinity.
• Evaluate the impact of galaxy mergers on the quenching of star formation and discuss how this process affects galaxy evolution.
  • Galaxy mergers can significantly impact the quenching of star formation by triggering complex gravitational interactions that lead to gas stripping and redistribution. When two galaxies collide, their gas reservoirs can be disturbed or removed entirely, limiting the available material for new stars. This process not only quenches ongoing star formation but also plays a key role in shaping the evolutionary path of galaxies by transforming them into more massive systems with altered structures and stellar populations.
• Discuss the various mechanisms that lead to quenching of star formation and analyze how these mechanisms influence the long-term evolution of galaxies.
  • Several mechanisms contribute to the quenching of star formation, including feedback from supernovae, active galactic nuclei, and environmental interactions like galaxy mergers. Each mechanism affects galaxies differently; for instance, AGN feedback can create powerful outflows that expel gas while suppressing further star formation. These processes not only change the immediate conditions within galaxies but also have long-term implications by affecting their growth rates and morphologies, leading to distinct evolutionary tracks that shape their place in the universe.

Related terms

Starburst: A starburst is a period of intense star formation in a galaxy, often leading to the rapid creation of new stars and significant changes in the galaxy's properties.

Feedback Mechanisms: Feedback mechanisms are processes that regulate star formation and galaxy evolution through energy and momentum transfer from stars or black holes, influencing the surrounding interstellar medium.

Active Galactic Nuclei (AGN): Active Galactic Nuclei are regions at the centers of some galaxies that emit enormous amounts of energy, often due to accretion of material onto supermassive black holes, which can drive outflows that affect star formation.