Barred spiral

Definition

A barred spiral galaxy is a type of galaxy characterized by its central bar-shaped structure composed of stars, which extends from the core and leads into spiral arms. This unique morphology is significant as it influences the dynamics and evolution of the galaxy, often resulting in enhanced star formation in the spiral arms compared to non-barred spirals.

5 Must Know Facts For Your Next Test

1. Barred spiral galaxies make up about two-thirds of all spiral galaxies observed in the universe.
2. The bar structure in these galaxies helps funnel gas towards the center, which can trigger bursts of star formation in the arms.
3. Examples of barred spiral galaxies include the Milky Way, NGC 1300, and NGC 1365.
4. The presence of a bar can also influence the rotation curve of the galaxy, impacting how stars and gas move within it.
5. Barred spirals are often more stable than regular spirals, allowing them to maintain their shape over longer periods.

Review Questions

• What role does the bar structure in barred spiral galaxies play in their overall dynamics?
  • The bar structure in barred spiral galaxies acts as a gravitational force that funnels gas toward the center of the galaxy. This process enhances star formation rates in the spiral arms by concentrating material where it can ignite new stellar births. Additionally, this dynamic flow can stabilize the structure of the galaxy, leading to more orderly motion among stars and gas.
• Compare and contrast barred spiral galaxies with non-barred spiral galaxies in terms of their formation and star formation rates.
  • Barred spiral galaxies typically have higher star formation rates compared to non-barred spirals due to their unique bar structures that channel gas towards the galactic center. This influx of material can lead to more vigorous star formation in the arms. In contrast, non-barred spirals may have more distributed gas but lack the focused mechanism that promotes concentrated bursts of star activity seen in their barred counterparts.
• Evaluate how understanding barred spiral galaxies contributes to our broader knowledge of galaxy evolution and dynamics.
  • Studying barred spiral galaxies enhances our understanding of galaxy evolution by revealing how morphological features influence star formation and galactic stability. The interactions between bar structures and surrounding gas provide insight into the processes that drive galactic growth and change over time. By analyzing these systems, astronomers can better understand the life cycles of galaxies and the impact of gravitational dynamics on their evolution.

Related terms

Spiral Galaxy: A type of galaxy featuring a flat, rotating disk containing stars, gas, and dust, along with a central concentration of stars known as the bulge.

Galaxy Morphology: The classification of galaxies based on their shape and structure, including types like elliptical, spiral, and irregular.

Star Formation Rate:

The rate at which new stars are being created in a galaxy, often affected by factors such as gas density and the presence of stellar nurseries.