奇怪電波圓環

奇怪電波圓環^[3]（英語：Odd radio circle，簡稱ORC）是一種非常大且尚無法解釋的天體。它們在無線電波波長處，是邊緣較亮且高度圓形^[4]。截至2021 4月27日，已經觀察到五個這樣的天體（可能還有六個）^[5]^[6]^[7]^[8]^[9]^[10]^[11]。觀察到的ORC在無線電的波長下相當明亮，但在可見、紅外或X射線波長下卻都不可見^[5]^[6]。其中三個ORC位於星系的中心，這表明可能是這些星系形成了這種天體^[6]^[11]。

概述

ORC是天文學家安娜·卡賓斯卡（英語：Anna Kapinska）研究基於澳大利亞平方公里陣列探路者（ASKAP）無線電望遠鏡陣列的宇宙演化圖計劃（英語：Evolutionary Map of the Universe）（EMU）的試點調查後，於2019年底發現的^[12]。所有觀測到的ORC直徑都約為1弧分，處於高銀緯，距銀河平面有一段距離。圓環的成因不明，快速電波爆發，伽馬射線暴或中子星碰撞相關的球形衝擊波的可能性被考慮過。但是由於ORC擁有大角直徑的關係，研究人員認為如果與這些相關的話，那麼它必定發生在遙遠的過去，為宇宙中最遙遠且古老的一種天體，應該有着非常大的紅移^[8]。此外，根據天文學家的說法，"圓形特徵在電波天文影像中是眾所周知的，通常代表一個球形物體，如超新星遺跡、行星狀星雲、星周包層、正面朝向的圓盤面，如原行星盤或一個恆星形成星系，……它們也可能由校準誤差或反褶積不足引起的明亮光源周圍的成像資料偽缺陷（英語：Artifact (error)）引起。無線電影像中的這一類圓形特徵似乎並不對應於任何已知類型的天體或人工製品，而似乎是一類新的天體 ^[8]。

參考資料

^ ^1.0 ^1.1 Norris, Ray P; Collier, J D; Crocker, Roland M; Heywood, Ian; Macgregor, Peter; Rudnick, L; Shabala, Stas; Andernach, Heinz; da Cunha, Elisabete; English, Jayanne; Filipović, Miroslav. MeerKAT uncovers the physics of an Odd Radio Circle. Monthly Notices of the Royal Astronomical Society. 2022-03-24, 513: 1300–1316. ISSN 0035-8711. arXiv:2203.10669 . doi:10.1093/mnras/stac701 （英語）.
^ ^2.0 ^2.1 Norris, Ray. 'Odd radio circles' that baffled astronomers are likely explosions from distant galaxies. The Conversation. [2022-03-30] （英語）.
^ 天文學家震驚！宇宙中出現4個從未發現過的物體. 自由時報. 2020-07-10 [2020-07-16]. （原始內容存檔於2020-07-16）.
^ Norris, Ray. 'WTF?': newly discovered ghostly circles in the sky can't be explained by current theories, and astronomers are excited. The Conversation Australia. 1 December 2020 [14 December 2020]. （原始內容存檔於2020-12-16）.
^ ^5.0 ^5.1 Norris, Ray P.; et al. Unexpected Circular Radio Objects at High Galactic Latitude. Publications of the Astronomical Society of Australia. 2021, 38. Bibcode:2021PASA...38....3N. S2CID 220128279. arXiv:2006.14805v1 . doi:10.1017/pasa.2020.52.
^ ^6.0 ^6.1 ^6.2 Johnson-Groh, Mara. 4 mysterious objects spotted in deep space are unlike anything ever seen. Live Science. 8 July 2020 [9 July 2020]. （原始內容存檔於2020-07-09）.
^ Murugesu, Jason Arunn. Circles in space made of radio waves are like nothing we've ever seen. New Scientist. 3 July 2020 [9 July 2020]. （原始內容存檔於2020-07-08）.
^ ^8.0 ^8.1 ^8.2 Starr, Michelle. Astronomers Detect Unexpected Class of Mysterious Circular Objects in Space. ScienceAlert. 9 July 2020 [9 July 2020]. （原始內容存檔於2020-07-09）.
^ Osborne, Hannah. 'Odd' Circles of Radio Waves Coming from Unknown Cosmic Source Discovered. Newsweek. 9 July 2020 [10 July 2020]. （原始內容存檔於2020-07-09）.
^ Ferreira, Becky. Scientists Discover Unexplained Glowing Circles of Energy in Space - Scientists believe they have likely discovered a new and unexplained class of space object: the Odd Radio Circle, or ORC.. Vice. 10 July 2020 [11 July 2020]. （原始內容存檔於2020-07-11）.
^ ^11.0 ^11.1 Nowakowski, Tomasz. Astronomers discover a new extragalactic circular radio source. Phys.org. May 4, 2021 [4 May 2021]. （原始內容存檔於2022-09-22）.
^ Rod, Isabelle. Astronomy: 'Odd radio circles' in the sky a 'genuine mystery'. BBC World News. 2020-12-07 [2020-12-08]. （原始內容存檔於2021-01-29）.

外部連結

Images of ORCs （頁面存檔備份，存於互聯網檔案館） (CTA Observatory（英語：Cherenkov Telescope Array） / Western Sydney University; 04/20/2020)
YouTube上的Video (9:16): ORCs (Anton Petrov; 07/15/2020)
YouTube上的Video (2:24): ORCs (Mr. Researcher; 07/10/2020)
YouTube上的Video (8:37): ORCs (World Today; 07/09/2020)

[:0-1] 1.0 ^1.1 Norris, Ray P; Collier, J D; Crocker, Roland M; Heywood, Ian; Macgregor, Peter; Rudnick, L; Shabala, Stas; Andernach, Heinz; da Cunha, Elisabete; English, Jayanne; Filipović, Miroslav. MeerKAT uncovers the physics of an Odd Radio Circle. Monthly Notices of the Royal Astronomical Society. 2022-03-24, 513: 1300–1316. ISSN 0035-8711. arXiv:2203.10669 . doi:10.1093/mnras/stac701 （英語）.

[:1-2] 2.0 ^2.1 Norris, Ray. 'Odd radio circles' that baffled astronomers are likely explosions from distant galaxies. The Conversation. [2022-03-30] （英語）.

[3] 天文學家震驚！宇宙中出現4個從未發現過的物體. 自由時報. 2020-07-10 [2020-07-16]. （原始內容存檔於2020-07-16）.

[TC-20201201-4] Norris, Ray. 'WTF?': newly discovered ghostly circles in the sky can't be explained by current theories, and astronomers are excited. The Conversation Australia. 1 December 2020 [14 December 2020]. （原始內容存檔於2020-12-16）.

[ARX-20200726-5] 5.0 ^5.1 Norris, Ray P.; et al. Unexpected Circular Radio Objects at High Galactic Latitude. Publications of the Astronomical Society of Australia. 2021, 38. Bibcode:2021PASA...38....3N. S2CID 220128279. arXiv:2006.14805v1 . doi:10.1017/pasa.2020.52.

[LS-20200709-6] 6.0 ^6.1 ^6.2 Johnson-Groh, Mara. 4 mysterious objects spotted in deep space are unlike anything ever seen. Live Science. 8 July 2020 [9 July 2020]. （原始內容存檔於2020-07-09）.

[NS-20200703-7] Murugesu, Jason Arunn. Circles in space made of radio waves are like nothing we've ever seen. New Scientist. 3 July 2020 [9 July 2020]. （原始內容存檔於2020-07-08）.

[SA-20200709-8] 8.0 ^8.1 ^8.2 Starr, Michelle. Astronomers Detect Unexpected Class of Mysterious Circular Objects in Space. ScienceAlert. 9 July 2020 [9 July 2020]. （原始內容存檔於2020-07-09）.

[NW-20200709-9] Osborne, Hannah. 'Odd' Circles of Radio Waves Coming from Unknown Cosmic Source Discovered. Newsweek. 9 July 2020 [10 July 2020]. （原始內容存檔於2020-07-09）.

[VICE-20200710-10] Ferreira, Becky. Scientists Discover Unexplained Glowing Circles of Energy in Space - Scientists believe they have likely discovered a new and unexplained class of space object: the Odd Radio Circle, or ORC.. Vice. 10 July 2020 [11 July 2020]. （原始內容存檔於2020-07-11）.

[PHYS-20210504-11] 11.0 ^11.1 Nowakowski, Tomasz. Astronomers discover a new extragalactic circular radio source. Phys.org. May 4, 2021 [4 May 2021]. （原始內容存檔於2022-09-22）.

[Anna_Kapinska's_discovery_of_WTF_ORCS-12] Rod, Isabelle. Astronomy: 'Odd radio circles' in the sky a 'genuine mystery'. BBC World News. 2020-12-07 [2020-12-08]. （原始內容存檔於2021-01-29）.

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概述

相關條目

參考資料

外部連結