Which characteristics are considered most typical of an old galaxy in decline?(1 point)
Responses
low gas content, little star formation
shrinking in size, high dust content
very bright, relatively small
spiral, abundant planets present
low gas content, little star formation
a nearby galaxy
a much larger galaxy
Which factor is essential to the initial formation of galaxies, for either of the theories describing galaxy evolution?(1 point)
Responses
The force of orbiting stars generates collisions.
Small lumps of material merge into larger clumps.
Massive gas and dust clouds collapse.
Gravity acts on existing material, shaping it into a new form.
With which type of galaxy is a small galaxy most likely to merge? Select the two correct answers.(1 point)
Responses
a nearby galaxy
a much larger galaxy
a fast-moving galaxy
an equal-sized galaxy
The most typical characteristics of an old galaxy in decline include:
1. Low gas content: As a galaxy ages, it tends to run out of the gas necessary for the formation of new stars. Therefore, a decline in gas content is a characteristic often observed in old galaxies.
2. Little star formation: With lower gas content, there is a decrease in the formation of new stars in older galaxies. A decline in star formation is another typical characteristic of an aging galaxy.
Therefore, the correct response is:
- Low gas content, little star formation (1 point)
To determine which characteristics are considered most typical of an old galaxy in decline, we can consider the known properties and behaviors of such galaxies.
One point to consider is the low gas content and little star formation. As galaxies age, they exhaust their gas reservoirs used to form new stars. This results in a decline in the amount of gas available for star formation and a decrease in the overall rate of star formation.
Another characteristic is the shrinking in size and high dust content. As a galaxy ages and evolves, it is likely to undergo interactions with other galaxies or astrophysical processes that can cause it to gradually shrink in size. Additionally, the accumulation of dust in an older galaxy can contribute to its overall decline.
Concerning the characteristic of being very bright and relatively small, this is not necessarily typical of an old galaxy in decline. The brightness of a galaxy can vary depending on various factors such as its age, size, and the presence of active galactic nuclei. Similarly, the size of a galaxy can also vary, and it is not necessarily indicative of its decline.
Lastly, the presence of spiral structure and abundant planets is not necessarily associated with the decline of an old galaxy. Spiral structure can be present in galaxies of various ages, and the existence of planets is not directly related to the age or decline of a galaxy.
To summarize, the most typical characteristics of an old galaxy in decline would include low gas content, little star formation, shrinking in size, and high dust content.