Quelltext der Seite Benutzer:W.pseudon/Event Horizon Telescope

[[Datei:Sagittarius_A*.jpg|thumb|Röntgenbild von [[Sagittarius A*]] und zwei [[Lichtecho]]s (markiert) einer früheren Explosion|300px]]

The '''Event Horizon Telescope''' ('''EHT''') is a project to create a large [[Astronomical interferometer|telescope array]] consisting of a global network of [[radio telescope]]s and combining data from several [[very-long-baseline interferometry]] (VLBI) stations around the Earth. The aim is to observe the immediate environment of the [[Milky Way]]'s [[supermassive black hole]] [[Sagittarius A*]] with [[angular resolution]] comparable to the black hole's [[event horizon]].<ref>[http://adsabs.harvard.edu/abs/2000ApJ...528L..13F Viewing the Shadow of the Black Hole at the Galactic Center]</ref><ref>[http://adsabs.harvard.edu/abs/2001ApJ...555L..83B Polarimetric Imaging of the Massive Black Hole at the Galactic Center]</ref><ref>[http://eventhorizontelescope.org/index.html Main project website]</ref><ref name="NYT-20150608">{{cite news |last=Overbye |first=Dennis |authorlink=Dennis Overbye |title=Black Hole Hunters |url=http://www.nytimes.com/2015/06/09/science/black-hole-event-horizon-telescope.html |date=8 June 2015 |work=[[NASA]] |accessdate=8 June 2015 }}</ref><ref name="NYT-20150608-do">{{Cite news |last1=Overbye |first1=Dennis |last2=Corum |first2=Jonathan |last3=Drakeford |first3=Jason |title=Video: Peering Into a Black Hole |url=http://www.nytimes.com/video/science/100000003725182/peering-into-a-black-hole.html |work=[[New York Times]] |date=8 June 2015 |accessdate= 9 June 2015 |issn = 0362-4331}}</ref>

== Überblick ==

The EHT is composed of many radio observatories or radio telescope facilities around the world to produce a high-sensitivity, high-angular-resolution telescope.  Through the technique of [[very-long-baseline interferometry]] (VLBI), many independent radio antennae separated by hundreds or thousands of miles can be used in concert to create a "virtual" telescope with an effective diameter of the entire planet.<ref name="O'Neil2015">{{cite news |last=O'Neill |first=Ian |url=http://news.discovery.com/space/astronomy/event-horizon-telescope-will-probe-spacetimes-mysteries-150702.htm |title=Event Horizon Telescope Will Probe Spacetime's Mysteries |work=Discovery News |date=2 July 2015 |accessdate=2015-08-21 }}</ref> The effort includes development and deployment of [[Submillimetre astronomy|submillimeter]] dual polarization receivers, highly stable frequency standards to enable very-long-baseline interferometry at 230–450&nbsp;GHz, higher-bandwidth VLBI backends and recorders, as well as commissioning of new submillimeter VLBI sites.<ref>[http://www.haystack.mit.edu/ast/uvlbi/mm/eht.html MIT Haystack observatory]</ref>

Each year since its first data capture in 2006, the EHT array has moved to add more observatories to its global network of radio telescopes. The first image of the Milky Way's supermassive black hole, Sagittarius A*, could be produced in 2017,<ref>{{cite news |last=Webb |first=Jonathan |url=http://www.bbc.com/news/science-environment-35258378 |title=Event horizon snapshot due in 2017 |work=BBC News |date=8 January 2016 |accessdate=2016-03-24 }}</ref> and it will also test Einstein's [[general relativity]] at the extreme.<ref name="O'Neil2015"/>

Data collected on hard drives must be transported by jet airliner (a so-called [[sneakernet]]) from the various telescopes to the MIT [[Haystack Observatory]] in Massachusetts, USA, where the data are cross-compared and analyzed on a grid computer made from about 800 CPUs all connected through a {{nowrap|40 Gbit/s}} network.<ref>{{cite news |last=Mearian |first=Lucas |url=http://www.computerworld.com/article/2972251/space-technology/massive-telescope-array-aims-for-black-hole-gets-gusher-of-data.html |title=Massive telescope array aims for black hole, gets gusher of data |work=Computer World |date=18 August 2015 |accessdate=2015-08-21 }}</ref>

== Beteiligte Institute ==
[[Datei:JCMT mirror from behind.jpg|mini|Rückseite des 15&nbsp;Meter großen [[James Clerk Maxwell Telescope|James-Clerk-Maxwell-Teleskops]]]]
Hier sind einige der beteiligten Institute aufgelistet:<ref>[http://www.eventhorizontelescope.org/collaborators/index.html Event Horizon Telescope – Collaborators]. August 2016.</ref>

* [[Atacama Large Millimeter Array|ALMA]]
* [[Atacama Pathfinder Experiment|APEX]]
* [[Academia Sinica]] Institut for Astronomy and Astrophysics
* [[Arizona Radio Observatory]], [[University of Arizona]]
* [[Caltech Submillimeter Observatory]]
* [[Combined Array for Research in Millimeter-wave Astronomy]]
* [[European Southern Observatory]]
* [[Georgia State University]]
* [[Goethe-Universität Frankfurt am Main]]
* Greenland Telescope
* [[Harvard–Smithsonian Center for Astrophysics]]
* [[Haystack Observatory]], [[Arizona Radio Observatory|MIT]]
* [[Institut de Radio Astronomie Millimetrique]]
* Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE)
* [[Joint Astronomy Centre]] – [[James Clerk Maxwell Telescope]]
* [[Large Millimeter Telescope]]
* [[Max-Planck-Institut für Radioastronomie]]
* [[National Astronomical Observatory of Japan]]
* [[National Radio Astronomy Observatory]]
* [[National Science Foundation]]
* [[University of Massachusetts]], Amherst
* [[Onsala Space Observatory]]
* [[Perimeter Institute]]
* [[Radio Astronomy Laboratory]], [[UC Berkeley]]
* Radboud University
* Shanghai Astronomical Observatory (SHAO)
* Universidad de Concepción
* Universidad Nacional Autónoma de México (UNAM)
* University of California – Berkeley (RAL)
* University of Chicago (South Pole Telescope)
* University of Illinois Urbana-Champaign
* University of Michigan



== Literatur ==

* D. Psaltis, S. Doeleman: ''Wie vermisst man ein Schwarzes Loch?'' In: [[Spektrum der Wissenschaft]] 2/16, [[Spektrum der Wissenschaft Verlagsgesellschaft]], Heidelberg 2016, {{ISSN|0170-2971}}
* J. A. Zensus u.a.:[http://www.mpifr-bonn.mpg.de/mitteilungen/2015/6 Ein Scharfer Blick auf Schwarze Löcher], Pressemitteilung vom Max-Planck-Institut für Radioastronomie (21. April 2015)
* F. Melia:[http://press.princeton.edu/titles/7480.html The Black Hole at the Center of Our Galaxy] (2001), ([[Princeton University Press]]), ISBN  0691095051
* F. Melia:[http://press.princeton.edu/titles/8453.html The Galactic Supermassive Black Hole] (2008), ([[Princeton University Press]]), {{ASIN|B008VQXCN2}}

== Weblinks ==
* [http://eventhorizontelescope.org/|Offizielle Website]
* [http://www.nytimes.com/video/science/100000003725182/peering-into-a-black-hole.html?emc=edit_au_20150609&nl=afternoonupdate&nlid=68634180 Peering into a Black Hole], New York Times Video 2015

== Einzelnachweise ==
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Kategorien:
Bodengebundenes ObservatoriumGroßteleskop (Radiobereich)