Description: 活动星系核（AGN）是位于星系中心的一个非常明亮的区域。人们认为它是由一个超大质量黑洞驱动的，黑洞吸积周围的物质，在其周围形成一个极热的吸积盘。AGN具有相当复杂的结构，有许多不同的区域发出不同特性的光，并且通常被甜甜圈状的环形尘埃包围。AGN有时会向相反的方向喷射物质。虽然许多星系的中心都有一个超大质量黑洞，但并非所有黑洞都在吸积物质，因此也并非所有星系中心都是AGN。

AGN是一个统称，包括类星体、耀变体、赛弗特星系和射电星系。人们认为这些天体的不同观测特性部分是由于从不同角度观察AGNs造成的。

Related Terms:

• Disk
• Galaxy
• Quasar
• Supermassive Black Hole
• Accretion Disk

Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

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