Which characteristics are considered most typical of an old galaxy in decline?(1 point) Responses spiral, abundant planets present spiral, abundant planets present very bright, relatively small very bright, relatively small low gas content, little star formation low gas content, little star formation shrinking in size, high dust content
low gas content, little star formation
The characteristics considered most typical of an old galaxy in decline include:
1. Low gas content and little star formation: As a galaxy ages, it generally exhausts its supply of gas, which is needed to form new stars. Therefore, an old galaxy in decline typically has a reduced amount of gas and experiences limited or negligible star formation.
2. Shrinking in size and high dust content: Over time, an old galaxy may undergo a process called "galactic cannibalism," where it merges with other galaxies, leading to a decrease in size. This process also results in the accumulation of dust within the galaxy, causing a higher dust content.
It is worth noting that while these characteristics can be commonly observed in old galaxies in decline, not all old galaxies exhibit all of these traits, as galactic evolution can vary.
The correct answer is: low gas content, little star formation.
To determine this answer, we need to understand the characteristics of old galaxies in decline. When a galaxy reaches its late stage of evolution, it tends to exhibit certain characteristics that indicate its decline and aging.
One of these characteristics is a decrease in gas content. As galaxies age, they consume their gas reservoirs for star formation, leading to a depletion of gas over time. This decline in gas content limits further star formation and reduces the overall activity within the galaxy.
Additionally, old galaxies in decline experience a significant decrease in star formation. Since their gas supplies dwindle, the production of new stars becomes less frequent. This reduction in star formation activity contributes to the overall aging process of the galaxy.
The other provided options, such as spiral structure, abundant planets, very bright and relatively small, and high dust content with a smaller size, do not necessarily indicate an old galaxy in decline. They might be characteristics of different types of galaxies or could be found in galaxies at various stages of their evolution.
Hence, the most typical characteristics of an old galaxy in decline are low gas content and little star formation.