View source for Astronomy:APM 08279+5255

{{Short description|Quasar}}
{{Infobox quasar
| name = APM 08279+5255
| image = File:Quasar in Water Vapor concept.jpg
| caption = Artist's concept of a quasar similar to APM 08279+5255
| epoch = J2000
| ra = {{RA|08|31|41.70}}<ref name=SIMBAD />
| dec = {{DEC|52|45|16.8}}<ref name=SIMBAD /> 
| constellation name = [[Astronomy:Lynx (constellation)|Lynx]]
| z = 3.911<ref name=Riechers2009 />
| dist_ly = {{convert|23.6|Gly|Gpc|abbr=on|lk=on}} {{hub|0.73}}<ref name=Wright2006 /><br/>(co-moving)<br/>12.05 Gly<ref name=Wright2006 /><br/>(light travel time)
| type = broad absorption line (BAL) quasar,<br/>hyper[[Astronomy:Luminous infrared galaxy|luminous infrared galaxy]]<ref name=NED />
| appmag_v =15.2 <small>{{abbr|(R)|with red filter}}</small><ref name=Irwin1998 />
| size_v =
| notes = [[Astronomy:Gravitational lens|gravitationally lensed]]<ref name=SIMBAD />
| names = [[Astronomy:IRAS|IRAS]] F08279+5255, [[Astronomy:Quasar|QSO]] B0827+5255, QSO J0831+5245<ref name=SIMBAD />
| luminosity = 10<sup>14</sup> to 10<sup>15</sup> L<sub>⊙</sub><ref name=Ibata1999 />
}}
{{Sky|08|31|41.70|+|52|45|16.8|2360000}}
'''APM 08279+5255''' is a very distant, broad absorption line [[Astronomy:Quasar|quasar]] located in the constellation [[Astronomy:Lynx (constellation)|Lynx]]. It is magnified and split into multiple images by the [[Astronomy:Gravitational lens|gravitational lens]]ing effect of a foreground galaxy through which its light passes. It appears to be a giant [[Astronomy:Elliptical galaxy|elliptical galaxy]] with a [[Astronomy:Supermassive black hole|supermassive black hole]] and associated [[Astronomy:Accretion disk|accretion disk]]. It possesses large regions of hot dust and molecular gas, as well as regions with [[Astronomy:Starburst region|starburst]] activity.

==Gravitational lensing==

APM 08279+5255 was initially identified as a quasar in 1998 during an Automatic Plate Measuring Facility (APM) survey to find [[Astronomy:Carbon star|carbon star]]s in the [[Astronomy:Galactic halo|galactic halo]]. The combination of its high [[Astronomy:Redshift|redshift]] (z=3.87) and brightness (particularly in the infrared) made it the most [[Astronomy:Luminosity|luminous]] object yet seen in the universe. It was suspected of being a gravitationally lensed object, with its luminosity magnified.<ref name=Irwin1998 /> Observations in the infrared with the [[Astronomy:Near Infrared Camera and Multi-Object Spectrometer|NICMOS]] high-resolution camera on board the [[Astronomy:Hubble Space Telescope|Hubble Space Telescope]] (HST) showed that the source was composed of three discrete images. Even accounting for the magnification, the quasar is an extremely powerful object, with a luminosity of 10<sup>14</sup> to 10<sup>15</sup> times the luminosity of the sun.<ref name=Ibata1999 /> Subsequent observations with the Hubble [[Astronomy:Space Telescope Imaging Spectrograph|Space Telescope Imaging Spectrograph]] confirmed the presence of a third faint image between the two brighter images. Each component has the same spectral energy distribution and is an image of the quasar. Gravitational lensed systems with odd numbers of images are extremely rare; most contain two or four.<ref name=Lewis2002 />

Initially the magnification due to gravitational lensing was thought to be large, in the range of 40 to 90 times.<ref name=Irwin1998 /><ref name=Ibata1999 /> After detailed observations at many wavelengths, the best model of the lensing galaxy is a tilted [[Spiral galaxy|spiral galaxy]]. This gives a magnification of about 4. The additional observations led to a revised redshift of 3.911.<ref name=Riechers2009 />

== Galactic structure ==
APM 08279+5255 is a bright source at almost all wavelengths and has become one of the most studied of distant sources. Using [[Astronomy:Astronomical interferometer|interferometry]] it has been mapped in [[Astronomy:X-ray astronomy|X-ray]] with the AXAF CCD Imaging Spectrometer on the [[Astronomy:Chandra X-ray Observatory|Chandra X-ray Observatory]], in [[Astronomy:Infrared astronomy|infrared]] with the Hubble Space Telescope, and in [[Astronomy:Radio astronomy|radio]] with the [[Astronomy:Very Long Baseline Array|Very Long Baseline Array]]. Measurements with the IRAM [[Astronomy:Plateau de Bure Interferometer|Plateau de Bure Interferometer]] and other instruments looked at the distribution of molecules such as [[Chemistry:Carbon monoxide|CO]], [[Chemistry:Cyanide|CN]], [[Chemistry:Hydrogen cyanide#HCN in space|HCN]], and HCO+ as well as atomic [[Chemistry:Carbon|carbon]].<ref name=Riechers2009 />

From these observations APM 08279+5255 is in a giant elliptical galaxy with large amounts of gas, dust, and an [[Active galactic nucleus|active galactic nucleus]] (AGN) at its core. The AGN is radio-quiet with no evidence for a relativistic jet.  It is powered by one of the [[Astronomy:List of most massive black holes|largest known]] supermassive black holes: 23 billion solar masses (based on the molecular disk velocities<ref name=Riechers2009 />); or alternatively 10 billion solar masses (based on [[Astronomy:Reverberation mapping|reverberation mapping]]<ref name="saturni2016"/>).  The black hole is surrounded by an accretion disk of material spiraling into it, a few [[Astronomy:Parsec|parsec]]s in size. Further out is a dust torus, a doughnut shaped cloud of dust and gas with a radius of about 100 parsecs. Both the accretion disk and dust torus appear to be almost face-on to us.<ref name=Riechers2009 /> The radiation from the molecular gas is coming from a flattened disk at the center of the galaxy with a radius of 550 pc. This is also the [[Astronomy:Starburst region|starburst region]] of the galaxy. The gas is heated both by activity in the AGN and by the newly forming stars.<ref name=Riechers2009 />

APM is an [[Astronomy:Luminous infrared galaxy#ULIRG|ultra-luminous infrared galaxy]] (ULIRG). Its high redshift shifts the far-infrared spectrum into [[Physics:Extremely high frequency|millimeter wavelengths]] where it can be observed from observatories on the ground. In 2008 and 2009 the intensities of its [[Physics:Water vapor|water vapor]] [[Physics:Spectral line|spectral line]]s were measured using the millimeter wave spectrometer Z-Spec at the [[Astronomy:Caltech Submillimeter Observatory|Caltech Submillimeter Observatory]]. Comparing the spectrum to that of [[Astronomy:Markarian 231|Markarian 231]], another ULIRG, showed that it had 50 times the water vapor of that galaxy.<ref name=Bradford2011 /> This made it the largest mass of water in the known universe—100 trillion times more water than that held in all of Earth's oceans combined. Its discovery shows that water has been prevalent in the known universe for nearly its entire existence; the radiation was emitted 1.6 billion years after the [[Astronomy:Big Bang|Big Bang]].<ref>{{cite web |url=http://www.science20.com/news_articles/apm_082795255_largest_water_mass_universe_so_far-81124 |title=APM 08279+5255 - The Largest Water Mass In The Universe (So Far) |work=Science 2.0 |publisher=ION Publishing |date=July 22, 2011 |accessdate=24 April 2014}}</ref>

==Gallery==
<gallery mode="nolines" widths=500px heights=500px>
File:quasar Mark Johnston.jpg|Amateur astronomer photo of APM 08279+5255
</gallery>

==References==
{{reflist|refs=

<ref name=Bradford2011>{{cite journal |first1=C. M. |last1=Bradford |first2=A. D. |last2=Bolatto |first3=P. R. |last3=Maloney |title=The Water Vapor Spectrum of APM 08279+5255: X-Ray Heating and Infrared Pumping over Hundreds of Parsecs |journal=The Astrophysical Journal |year=2011 |volume=741 |issue=2 |pages=L37 (6 pp.)|bibcode=2011ApJ...741L..37B |doi=10.1088/2041-8205/741/2/L37|arxiv = 1106.4301 |s2cid=28580964 |display-authors=0}}</ref>

<ref name=Ibata1999>{{cite journal |first1=Rodrigo A. |last1=Ibata |first2=Geraint F. |last2=Lewis |first3=Michael J. |last3=Irwin |first4=Joseph |last4=Lehár |first5=Edward J. |last5=Totten |display-authors=3  |title=NICMOS and VLA Observations of the Gravitationally Lensed Ultraluminous BAL Quasar APM 08279+5255: Detection of a Third Image |journal=The Astronomical Journal |year=1999 |volume=118 |issue=5 |pages=1922–1930 |bibcode=1999AJ....118.1922I |doi=10.1086/301111|arxiv = astro-ph/9908052 |s2cid=14818874 }}</ref>

<ref name=Irwin1998>{{cite journal |last1=Irwin |first1=Michael J. |last2=Ibata |first2=Rodrigo A. |last3=Lewis |first3=Geraint F. |last4=Totten |first4=Edward J. |year=1998 |title=APM 08279+5255: An Ultraluminous Broad Absorption Line Quasar at a Redshift z = 3.87 |journal=[[Astronomy:The Astrophysical Journal|The Astrophysical Journal]] |volume=505 |issue=2 |pages=529–535 |doi=10.1086/306213 |arxiv=astro-ph/9806171 |bibcode=1998ApJ...505..529I|s2cid=14924830 }}</ref>

<ref name=Lewis2002>{{cite journal |first1=Geraint F. |last1=Lewis |first2=Rodrigo A. |last2=Ibata |first3=Sara L. |last3=Ellison |first4=Bastien |last4=Aracil |first5=Patrick |last5=Petitjean |first6=Max |last6=Pettini |first7=Raghunathan |last7=Srianand |display-authors=3 |title=Spatially resolved STIS spectra of the gravitationally lensed broad absorption line quasar APM08279+5255: the nature of component C and evidence for microlensing |journal=Monthly Notices of the Royal Astronomical Society |year=2002 |volume=334 |issue=1 |pages=L7–L10 |bibcode=2002MNRAS.334L...7L |doi=10.1046/j.1365-8711.2002.05700.x|arxiv = astro-ph/0205416 |s2cid=17837043 }}</ref>

<ref name=NED>{{cite web |title=Results for IRAS F08279+5255 |publisher=NASA/IPAC Extragalactic Database |url=http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=IRAS+F08279%2B5255+&extend=no |accessdate=8 April 2014}}</ref>

<ref name=Riechers2009>{{cite journal |last1=Riechers |first1=Dominik A. |last2=Walter |first2=Fabian |last3=Carilli |first3=Christopher L. |last4=Lewis |first4=Geraint F. |title=Imaging The Molecular Gas in a z = 3.9 Quasar Host Galaxy at 0."3 Resolution: A Central, Sub-Kiloparsec Scale Star Formation Reservoir in APM 08279+5255 |journal=The Astrophysical Journal |volume=690 |issue=1 |pages=463–485 |year=2009 |arxiv=0809.0754 |doi=10.1088/0004-637X/690/1/463 |bibcode =2009ApJ...690..463R|s2cid=13959993 }}</ref>

<ref name="saturni2016">{{cite journal
   | last1 = Saturni | first1 = F. G.
   | last2 = Trevese | first2 = D.
   | last3 = Vagnetti | first3 = F.
   | last4 = Perna | first4 = M.
   | last5 = Dadina | first5 = M.
   | title = A multi-epoch spectroscopic study of the BAL quasar APM 08279+5255. II. Emission- and absorption-line variability time lags
   | year = 2016
   | journal = Astronomy and Astrophysics
   | volume = 587
   | pages = A43
   | doi = 10.1051/0004-6361/201527152
   | arxiv = 1512.03195
   | url = http://esoads.eso.org/abs/2016A%26A...587A..43S
   | bibcode = 2016A&A...587A..43S
| s2cid = 118548618
 }}
</ref>

<ref name=SIMBAD>{{cite web |title=Basic data: QSO J0831+5245 — Quasar |url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=IRAS+F08279%2B5255&submit=SIMBAD+search |work=SIMBAD |publisher=Centre de Données astronomiques de Strasbourg |accessdate=8 April 2014}}</ref>

<ref name=Wright2006>{{cite journal |last=Wright |first=Edward L. |title=A Cosmology Calculator for the World Wide Web |journal=The Publications of the Astronomical Society of the Pacific |volume=118 |issue=850 |pages=1711–1715 |date=December 2006 |doi=10.1086/510102  |bibcode=2006PASP..118.1711W|arxiv = astro-ph/0609593 |s2cid=9225000 }}{{cite web |title=Ned Wright's Javascript Cosmology Calculator |url=http://www.astro.ucla.edu/~wright/CosmoCalc.html |accessdate=8 April 2014}}</ref>

}}

==External links==
* {{cite web |title=APM 08279+5255: Matter Near Black Hole Gets Second Lease On Life |url=http://chandra.harvard.edu/photo/2003/apm08279/ |work=Chandra X-ray Observatory: Photo Album |publisher=Harvard-Smithsonian Center for Astrophysics
 |date=25 March 2003 |accessdate=27 April 2014}}

[[Category:Lynx (constellation)]]
[[Category:Gravitationally lensed quasars]]
[[Category:IRAS catalogue objects]]
[[Category:Starburst galaxies]]
[[Category:Supermassive black holes]]

{{Sourceattribution|APM 08279+5255}}