超大質量黑洞的旋轉
Spin up of a Supermassive Black Hole
發表日期：2025-05-04
黑洞的旋轉速度有多快？ 如果任何由普通物質構成的物體旋轉得太快--它就會碎裂。但黑洞可能不會解體--它的最大自旋速度確實是個未知數。理論家們通常用愛因斯坦廣義相對論的克爾解來模擬快速旋轉的黑洞。 不過，它最容易驗證的預言也許是，從遠處看，進入最大旋轉黑洞的物質最後應該以接近光速的速度執行。美國宇航局的 NuSTAR 和歐空局的 XMM 衛星透過觀測螺旋星系 NGC 1365 中心的超大質量黑洞，驗證了這一預言。透過測量周圍吸積盤內緣核輻射的加熱和譜線增寬，證實了接近光速的極限。圖中是一幅藝術家繪製的插圖，描繪了一個由正常物質組成的吸積盤圍繞著黑洞旋轉，黑洞頂部噴射出一股噴流。由於隨機落入黑洞的物質不可能使黑洞旋轉得如此劇烈，NuSTAR 和 XMM 的測量結果也驗證了周圍吸積盤的存在。 洞穴新世界：今天是美國國家航空航天局的黑洞周！
原文：How fast can a black hole spin? If any object made of regular matter spins too fast -- it breaks apart. But a black hole might not be able to break apart -- and its maximum spin rate is really unknown. Theorists usually model rapidly rotating black holes with the Kerr solution to Einstein's General Theory of Relativity, which predicts several amazing and unusual things. Perhaps its most easily testable prediction, though, is that matter entering a maximally rotating black hole should be last seen orbiting at near the speed of light, as seen from far away. This prediction was tested by NASA's NuSTAR and ESA's XMM satellites by observing the supermassive black hole at the center of spiral galaxy NGC 1365. The near light-speed limit was confirmed by measuring the heating and spectral line broadening of nuclear emissions at the inner edge of the surrounding accretion disk. Pictured here is an artist's illustration depicting an accretion disk of normal matter swirling around a black hole, with a jet emanating from the top. Since matter randomly falling into the black hole should not spin up a black hole this much, the NuSTAR and XMM measurements also validate the existence of the surrounding accretion disk. Hole New Worlds: It's Black Hole Week at NASA!
※ 本文由萌芽機器人自動轉貼自每日一天文圖（Astronomy Picture of the Day，APOD），原文為英文，正體中文是透過 DeepL 翻譯及 OpenCC 進行自動處理，內容僅供參考，若有任何錯誤之處還請見諒！
關於每日一天文圖：每日一天文圖網站是美國國家航空暨太空總署與密西根理工大學提供的服務，網站每天提供一張影像或圖片，並由天文學家撰寫扼要說明其特別之處。