View source for RX J1131-1231

{{Short description|Supermassive-black-hole-containing quasar in the constellation Crater}}
{{Quasar
| name = RX J1131-1231
| image = [[File:Space telescopes measure black hole's spin cropped.jpg|300px]]
| caption= Combination image of quasar RX J1131 (four duplicate images of it appear along the ring in pink) taken via NASA’s Chandra X-ray Observatory and the Hubble Space Telescope.
| epoch = [[J2000]]
| ra = {{RA|11|31|51.60}}<ref name="Chandra"/>
| dec = {{DEC|-12|31|57.00}}
| constellation name = [[Crater (constellation)|Crater]]<ref name="Chandra"/>
| z = 0.658<ref name="Chandra"/>
| type =
| dist_ly = 6.05 Gly<ref name="Chandra"/>
| appmag_v =
| size_v =
| notes = rotation is half the speed of light, [[extragalactic planets]]
| names = [[Quasar|QSO]] J1131-1231, [[Lyon-Meudon Extragalactic Database|LEDA]] 3772549,  [[2MASX]] J11315154-1231587
}}
'''RX J1131-1231''' is a distant, [[Supermassive black hole|supermassive-black-hole]]-containing [[quasar]] located about 6 billion [[light years]] from Earth in the constellation [[Crater (constellation)|Crater]].<ref name="Chandra"/><ref>{{cite web|url=http://www.nasa.gov/mission_pages/chandra/multimedia/distant-quasar-RXJ1131.html#.UxfB_PldVv8|title=Distant Quasar RX J1131|publisher=[[NASA]]|date=March 5, 2014|accessdate=March 5, 2014}}</ref>
In 2014, astronomers found that the [[X-rays]] being emitted are coming from a region inside the [[accretion disk]] located about three times the radius of the [[event horizon]]. This implies that the black hole must be spinning incredibly fast to allow the disk to survive at such a small radius.<ref name="Chandra">{{cite web|url=http://chandra.harvard.edu/photo/2014/rxj1131/|title=Chandra & XMM-Newton Provide Direct Measurement of Distant Black Hole's Spin|publisher=Chandra X-ray Center|date=March 5, 2014|accessdate=March 5, 2014}}</ref> The measurement of the black hole's rotation is the first time astronomers have been able to directly measure the rotational speed of any black hole.<ref name="Space">{{cite web|url=http://www.space.com/24936-supermassive-black-hole-spin-quasar.html|title=Monster Black Hole Spins at Half the Speed of Light|author=Nola Taylor Redd|publisher=[[Space.com]]|date=March 5, 2014|accessdate=March 5, 2014}}</ref>
This determination was made by a team led by Rubens Reis of the [[University of Michigan]] using [[NASA]]'s [[Chandra X-ray Observatory]] and the [[European Space Agency]]'s [[XMM-Newton]] telescopes. The team observed the X-rays generated in the innermost regions of the disk circling and feeding the black hole that powers the quasar. By measuring the radius of the disk, the astronomers were able to calculate the black hole's rotational speed, which was almost half the speed of light. The rapid spin of the quasar indicates that the black hole is being fed by a vast supply of gas and dust.<ref name="Space"/>
However, the measurements would not have been possible without a rare alignment of the quasar and a giant [[elliptical galaxy]] (which is itself part of a [[Galactic cluster|cluster of other galaxies]] in line with the quasar) which lies between Earth and RX J1131-1231.<ref name="Space"/> This line-up provided a quadruple [[gravitational lens]] which magnified the light coming from the quasar. The strong gravitational lensing effect associated with RX J1131-1231 has also produced measured time delays; that is, in one image the lensed quasar will be observed before the other image.<ref>{{cite arXiv|last1=Morgan |first1=Nicholas |last2=Kochanek |first2=Christopher |date=May 2006  |title=Time-Delay Measurement for the Quadruple Lens RX J1131-1231|eprint=astro-ph/0605321}}</ref>
== Extragalactic planets ==
A population of [[unbound planet]]s between stars with masses ranging from [[Lunar mass|Moon]] to [[Jupiter mass]]es has been confirmed for the first time in the galaxy by the use of [[microlensing]] in 2018.<ref>{{Cite journal|arxiv=1802.00049|last1 = Dai|first1 = Xinyu|title = Probing Planets in Extragalactic Galaxies Using Quasar Microlensing|journal = The Astrophysical Journal|volume = 853|issue = 2|pages = L27|last2 = Guerras|first2 = Eduardo|year = 2018|doi = 10.3847/2041-8213/aaa5fb|bibcode = 2018ApJ...853L..27D|s2cid = 119078402 | doi-access=free }}</ref>
== Gallery ==
{{Gallery
|File:Jewelled ring Webb photo gravitational lensing of RX J1131-1231 cropped.tif|James Webb photo of the quasar gravitationally lensed by a galaxy|File:Mosaic of Gravitationally Lensed Quasars (2020-04-4606) cropped RX J1131-1231.tif|Combined Hubble and Chandra photo
|File:Space telescopes measure black hole's spin cropped.jpg|Combined Hubble and Chandra photo, with a different coloring}}
==See also==
* [[Einstein Cross]]
==References==
{{reflist}}
{{Crater (constellation)|state=collapsed}}
{{DEFAULTSORT:RX J1131-1231}}
[[Category:Astronomical X-ray sources]]
[[Category:Supermassive black holes]]
[[Category:Crater (constellation)]]
[[Category:Quasars]]
[[Category:University of Michigan]]
[[Category:LEDA objects|3772549]]