Avg pitch angles & spiral amplitudes in S4G

Spiral galaxies are very common in the local Universe, but their formation, evolution, and interplay with bars remain poorly understood after more than a century of astronomical...旋涡星系（spiral galaxies）在本地宇宙中极为常见，但历经一个多世纪的天文学研究，其形成、演化以及与星系棒的相互作用机制仍未被充分阐明……