ULAS J1342+0928

ULAS J1342+0928
	藝術家概念下相似的類星體。
觀測資料(曆元 J2000.0)
星座	牧夫座
赤經	13h 42m 08.10s
赤緯	+09° 28′ 38.61″
紅移	7.54
距離	29.36 Gly（9.00 Gpc）; （同移距離）; 13.1 Gly（4.0 Gpc）; （光程距離）
其他编号
	ULAS J134208.10+092838.61, Quasar20171206
	参见：類星體，類星體列表
	查; 论; 编;

ULAS J1342+0928為已知距離第二遙遠的的類星體，位於牧夫座^[3]，其中心也是已知最古老和最遙遠的超大質量黑洞之一^[1]^[5]^[6]^[7]。其紅移為z=7.54，超越之前被認為是最遙遠的類星體ULAS J1120+0641（紅移為z=7）^[1]，並且一直為最遙遠的類星體，直至2020年3月才被PSO J0309+27的133億光年的紀錄打破。相關報導中指出^[谁？]，其中心的超大質量黑洞的質量是太陽質量的8億倍^[5]。

發現

2017年12月6日^[1]，天文學家發表文章表示^[谁？]，他們使用廣域紅外線巡天探測衛星^[6]的資料，結合位在智利拉斯坎帕納斯天文台的麥哲倫望遠鏡、亞利桑那州的大雙筒望遠鏡和夏威夷的雙子北望遠鏡的觀測資料，當宇宙大約6.9億歲時，類星體與相關的黑洞就存在了（大約宇宙年齡的5%，目前已知的宇宙年齡為138億歲）^[1]。

這個類星體來自宇宙在黑暗時代嶄露頭角之後，被稱為再電離的時代^[5]。大量的氣體和塵埃被檢測到從類星體釋放進入宿主星系成為星際物質^[2]。

描述

ULAS J1342+0928被測量出7.54的紅移，這相當於距離地球294.6億光年的同移距離^[1]^[4]。截至2017年12月 (2017-12)^[update]，於當時為止觀測到距離最遙遠的類星體。在地球觀察到這個類星體輻射的光是在大爆炸之後不到6.9億年，也就是大約在131億年前輻射出來的^[5]^[8]。

估計這個類星體光度是7013400000000000000♠4×10¹³ 太陽光度^[1]。估計輸出這些能量的超大質量黑洞擁有7008800000000000000♠8×10⁸太陽質量^[1]。根據天文學家愛德華多·巴尼亞多斯（Eduardo Bañados）的資料^[9]，這個特殊的類星體是如此的明亮，它將成為後續研究的一個金礦，是研究早期宇宙的一個關鍵實驗室^[5]。

重要性

來自ULAS J1342+0928的光是理論預測星際物質從結束電中性成為電離狀態的過渡時期（再電離時期）。類星體在這個過程中可能是一個重要的能量來源，這標誌著黑暗時期，也就是宇宙的黑暗時代的終結。所以，觀察來自黑暗時期的過渡時期的類星體是理論學家主要的興趣所在^[10]^[11]。由於它們的高紫外線光度，類星體也是研究再電離過程的最好來源。這一發現也被描述為對黑洞形成理論具有挑戰性：通過在宇宙早期階段擁有一個比預期大得多的超大質量黑洞^[6]。然而，這並不是第一個能提供這樣挑戰的遙遠類星體 ^[12]^[13]。

少數的來源質疑^[谁？]，如此大質量的超大質量黑洞（如ULAS J1342+0928）很難解釋在大爆炸之後極短的時間內快速生成^[6]，可能證明我們的宇宙是大反彈的結果，而非大爆炸；是在大反彈之前形成這些超大質量黑洞^[14]^[15]。

參考資料

^ ^1.00 ^1.01 ^1.02 ^1.03 ^1.04 ^1.05 ^1.06 ^1.07 ^1.08 ^1.09 Bañados, Eduardo; et al. An 800-million-solar-mass black hole in a significantly neutral Universe at a redshift of 7.5. Nature. 6 December 2017 [6 December 2017]. Bibcode:2018Natur.553..473B. arXiv:1712.01860 . doi:10.1038/nature25180. （原始内容存档于2019-08-30）.
^ ^2.0 ^2.1 Venemans, Bram P.; et al. Copious Amounts of Dust and Gas in a z = 7.5 Quasar Host Galaxy. The Astrophysical Journal Letters. 6 December 2017, 851 (1) [6 December 2017].
^ ^3.0 ^3.1 Staff. Finding the constellation which contains given sky coordinates. djm.com. [6 December 2017]. （原始内容存档于2019-08-15）.
^ ^4.0 ^4.1 Wright, Ned. Ned Wright's Javascript Cosmology Calculator. UCLA. 24 April 2016 [7 December 2017]. （原始内容存档于2018-09-29）.
^ ^5.0 ^5.1 ^5.2 ^5.3 ^5.4 ^5.5 Choi, Charles Q. Oldest Monster Black Hole Ever Found Is 800 Million Times More Massive Than the Sun. Space.com. 6 December 2017 [6 December 2017]. （原始内容存档于2017-12-06）.
^ ^6.0 ^6.1 ^6.2 ^6.3 ^6.4 Landau, Elizabeth; Bañados, Eduardo. Found: Most Distant Black Hole. NASA. 6 December 2017 [6 December 2017]. （原始内容存档于2019-02-18）. "This black hole grew far larger than we expected in only 690 million years after the Big Bang, which challenges our theories about how black holes form," said study co-author Daniel Stern of NASA's Jet Propulsion Laboratory in Pasadena, California.
^ Decarli, Roberto; et al. Rest-frame optical photometry of a z-7.54 quasar and its environment. CalTech. September 2017 [6 December 2017]. （原始内容存档于2017-12-07）.
^ Grush, Loren. The most distant supermassive black hole ever found holds secrets to the early Universe - We’re seeing how it looked when the Universe was a toddler. TheVerge. 6 December 2017 [6 December 2017]. （原始内容存档于2017-12-10）.
^ Bañados, Eduardo. Eduardo Bañados - Bio/CV. Carnegie Institution for Science. 2017 [7 December 2017]. （原始内容存档于2019-02-03）.
^ Matson, John. Brilliant, but Distant: Most Far-Flung Known Quasar Offers Glimpse into Early Universe. Scientific American. 29 June 2011 [7 December 2017]. （原始内容存档于2013-11-03）.
^ Willott, C. Cosmology: A monster in the early Universe. Nature. 2011, 474 (7353): 583–584. Bibcode:2011Natur.474..583W. PMID 21720357. arXiv:1106.6090 . doi:10.1038/474583a. preprint of this paper （页面存档备份，存于互联网档案馆）
^ Davide Castelvecchi. Young black hole had monstrous growth spurt. Nature. 25 February 2015 [9 December 2017]. （原始内容存档于2021-05-27）. A black hole that grew to gargantuan size in the Universe's first billion years is by far the largest yet spotted from such an early date, researchers have announced. The object, discovered by astronomers in 2013, is 12 billion times as massive as the Sun, and six times greater than its largest-known contemporaries. Its existence poses a challenge for theories of the evolution of black holes, stars and galaxies, astronomers say. Light from the black hole took 12.9 billion years to reach Earth, so astronomers see the object as it was 900 million years after the Big Bang. That “is actually a very short time” for a black hole to have grown so large, says astronomer Xue-Bing Wu of Peking University in Beijing.
^ Discovery in the early universe poses black hole growth puzzle. Phys.org. 11 May 2015 [9 December 2017]. （原始内容存档于2017-12-09）. Now, researchers from the Max Planck Institute for Astronomy (MPIA) have discovered three quasars that challenge conventional wisdom on black hole growth. These quasars are extremely massive, but should not have had sufficient time to collect all that mass. The astronomers observed quasars whose light took nearly 13 billion years to reach Earth. In consequence, the observations show these quasars not as they are today, but as they were almost 13 billion years ago, less than a billion years after the big bang. The quasars in question have about a billion times the mass of the sun. All current theories of black hole growth postulate that, in order to grow that massive, the black holes would have needed to collect infalling matter, and shine brightly as quasars, for at least a hundred million years. But these three quasars proved to be have been active for a much shorter time, less than 100,000 years. "This is a surprising result," explains Christina Eilers, a doctoral student at MPIA and lead author of the present study. "We don't understand how these young quasars could have grown the supermassive black holes that power them in such a short time."
^ Jamie Seidel. Black hole at the dawn of time challenges our understanding of how the universe was formed. News Corp Australia. 7 December 2017 [9 December 2017]. （原始内容存档于2017-12-09）. It had reached its size just 690 million years after the point beyond which there is nothing. The most dominant scientific theory of recent years describes that point as the Big Bang — a spontaneous eruption of reality as we know it out of a quantum singularity. But another idea has recently been gaining weight: that the universe goes through periodic expansions and contractions — resulting in a “Big Bounce”. And the existence of early black holes has been predicted to be a key telltale as to whether or not the idea may be valid. This one is very big. To get to its size — 800 million times more mass than our Sun — it must have swallowed a lot of stuff. ... As far as we understand it, the universe simply wasn’t old enough at that time to generate such a monster.
^ Youmagazine staff. A Black Hole that is more ancient than the Universe. You Magazine (Greece). 8 December 2017 [9 December 2017]. （原始内容存档于2021-06-14）（希腊语）. This new theory that accepts that the Universe is going through periodic expansions and contractions is called "Big Bounce"