Twin Quasar

Twin Quasar
The Twin Quasar Q0957+561
Foto
Twin Quasar
Observation data (Epoch J2000)
Constellation Ursa Major
Right ascension 10h 01m 20.99s
Declination +55° 53′ 56.5″
Redshift 1.413
Distance 7,800,000,000 ly (2,400,000,000 pc)
Type Rad
Apparent dimensions (V) 6" distance
Apparent magnitude (V) 16.7
Other designations
Twin Quasar, Double Quasar, Twin QSO, QSO 0957+561, Q0957+561, SBS 0957+561, TXS 0957+561, 8C 0958+561, PGC 2518326, A: USNO-A2 1425-7427021 B:USNO-A2 1425-7427023
See also: Quasar, List of quasars
v · d · e

The Twin Quasar (Twin QSO or Double Quasar or Old Faithful), also known as SBS 0957+561, or TXS 0957+561 (also Q0957+561 or QSO 0957+561 A/B), was the first identified gravitationally lensed object.

Contents

Quasar

QSO 0957+561 A (SBS 0957+561 A) and QSO 0957+561 B (SBS 0957+561 B) are the two components of a double-imaged quasar, meaning that an intervening mass concentration between Earth and the quasar bends light so that two images of the quasar appear in the sky. This is known as gravitational lensing, and is a consequence of Einsteinian warped space-time. The quasar lies at redshift z = 1.41(8.7 billion ly), while the lensing galaxy lies at redshift z = 0.355 (3.7 billion ly). The lensing galaxy with apparent dimension of 0.42×0.22 arcminutes lies almost in line with the B image, lying 1 arcsecond off. The quasar lies 10 arcminutes north of NGC 3079, in the constellation Ursa Major. The astronomical data services SIMBAD and NASA/IPAC Extragalactic Database (NED) list several other names for this system.

The Twin Quasar's two images are separated by 6 arcseconds. Both images have an apparent magnitude of 17, with the A component having 16.7 and the B component having 16.5. There is a 417 ± 3 day time lag between the two images.[1]

Lens

The lensing galaxy, YGKOW G1[2] (sometimes called G1 or Q0957+561 G1), is a giant elliptical (type cD) lying within a cluster of galaxies that also contribute to the lensing.

History

The quasars QSO 0957+561A/B were discovered in early 1979 by an Anglo-American team around Dennis Walsh, Robert Carswell and Ray Weyman, with the aid of the 2.1 m Telescope at Kitt Peak National Observatory in Arizona/USA. The team noticed the two quasars not only being unusually close to each other, but redshift and visible light spectrum for these objects were surprisingly similar. They published their assumption of "the possibility that they are two images of the same object formed by a gravitational lens".[3]

The Twinquasar soon caught attention of professional astronomers, since it was one of the first directly observable gravitational lens effects, first described in 1915 by Albert Einstein in his General Theory of Relativity.[4]

Critics however indicated the difference between the two quasars in radio frequency. In mid 1979 a team around David Roberts at the VLA (Very Large Array) near Socorro, New Mexico/USA discovered a relativistic jet emerging from quasar A with no corresponding equivalent in quasar B.[5] Furthermore the distance between the two images, namely 6 arcseconds, was too great to have emerged from the galaxy G1, a galaxy found closely by quasar B.

Finally a team around Marc V. Gorenstein found axial symmetric (mirrored-imaged) relativistic jets in 1983 with the aid of high resolution pictures produced by VLBI (Very Long Baseline Interferometry). It was further discovered that galaxy G1 is part of a galaxy cluster which intensifies the deflection.

Slight spectral differences between quasar A and quasar B can be explained by different densities of the intergalactic medium in the light paths, resulting in differed extinction.[6]

30 years of observation made it clear that image A of the quasar reaches earth about 14 months earlier than the corresponding image B, obviously resulting in a range difference of 1.1 ly.

In 1996 a team at Harvard-Smithsonian Center for Astrophysics around Rudy E. Schild discovered a temporal anomaly which led to a controversial, and unconfirmable theory that there is a planet approximately three Earth masses in size in the lensing galaxy. The results remain speculative because the chance alignment that led to its discovery will never happen again; although hope is nurtured that fine structures in the early universe could be made observable with the aid of gravitational lensing effects. If it could be confirmed, however, it would make it the most distant known planet, 4 billion ly away.[7]

MECO possibility

R. E. Schild announced findings which suggest that the object at the heart of Q0957+561 is not a supermassive black hole, as is believed to be the case for all quasars, but a magnetospheric eternally collapsing object. Schild's team at the Harvard-Smithsonian Center for Astrophysics found that the jets originated 8000 AU from the poles of the centre, in a region 1000AU across, and that "this quasar appears to be dynamically dominated by a magnetic field internally anchored to its central, rotating supermassive compact object" (R. E. Schild). The accretion disc ends at 2000AU from the centre, and the inner edge is intensely radiating.[8][9]

See also

References

Citations

  1. ^ Kundic, T., Turner, E.L., Colley, W.N., Gott, III, R., and Rhoads, J.E., ``A robust determination of the time delay in 0957+561A,B and a measurement of the global value of Hubble's constant, Astrophys. J., 482, 75-82, (1997).
  2. ^ Nomenclature of Celestial Objects (Result I)
  3. ^ Nature 279, S.381-384: 0957 + 561 A, B: twin quasistellar objects or gravitational lens? D.Walsh, R.F.Carswell, R.J.Weymann 31.May 1979
  4. ^ Einstein, Albert (1936). Science. pp. pp. 506–507. 
  5. ^ TIME (October 1, 1979). "Science: The Mysterious Celestial Twins". Time. http://www.time.com/time/magazine/article/0,9171,947469-1,00.html. Retrieved 2011-01-31. 
  6. ^ "Quasare im Doppelpack" aus "Astro-Lexikon" Andreas Müller August 2007
  7. ^ New Scientist (issue 2037), Do alien worlds throng faraway galaxy? Govert Schilling 06 July 1996
  8. ^ Mysterious quasar casts doubt on black holes - New Scientist, July 27, 2006.
  9. ^ Research Sheds New Light On Quasars - SpaceDaily July 26, 2006.

External links

Coordinates: Sky map 10h 01m 20.99s, +55° 53′ 56.5″


Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • twin quasar — noun a pair of quasar images formed by gravitational lensing of a single physical quasar …   Wiktionary

  • Quasar Jumeau — Q0957+561 A+B Données d observation Époque J2000 Type d objet Quasar Ascension droite (α) 10h 01m 20.99s Déclinaison (δ) +55°  …   Wikipédia en Français

  • Twin Signal — Infobox animanga/Header name = Twin Signal caption = Cover of Twin Signal OVA. ja name = ツインシグナル ja name trans = Tsuin Sigunalu genre = Sci fiInfobox animanga/Manga title = author = Sachi Oshimizu publisher = Enix/Gangan Comics demographic =… …   Wikipedia

  • Einstein Cross — Quasar name = QSO 2237+0305 epoch = J2000 ra = RA|22|40|31 dec = DEC|+3|21|30.3 constellation name = Pegasus z = 1.695 dist ly = 8,000,000,000 ly (2,500,000,000) pc type =LeQ appmag v =16.78 size v = 0.870´ X 0.338´ notes = names =LEDA 69457, Z… …   Wikipedia

  • QSO B1359+154 — Quasar name = QSO B1359+154, QSO J1401+1513 caption= QSO B1359+154 epoch = J2000 ra = RA|14| 01| 35.6 dec = DEC| +15| 13| 25.0 constellation name = Boötes z =3.235 km/s type = dist ly = ly ( kpc) appmag v = 21.9 size v = notes = Six image lens,… …   Wikipedia

  • Q0957+561 — Datenbanklinks zu Q0957+561 Q0957+561 Beobachtungsdaten Äquinoktium: J2000.0 …   Deutsch Wikipedia

  • Einsteinkreuz — Datenbanklinks zu Einsteinkreuz Einsteinkreuz / Huchras Linse Beobachtungsdaten …   Deutsch Wikipedia

  • Sjur Refsdal — Prof Sjur Refsdal (born December 30, 1935) is a Norwegian astrophysicist, born in Oslo. He is best known for his pioneer work on gravitational lensing, including the Chang Refsdal lens.In 1970 he earned a PhD at the Institute of Theoretical… …   Wikipedia

  • Gravitationslinse — Als Gravitationslinseneffekt wird in der Astronomie die Ablenkung von Licht durch schwere Massen bezeichnet. Der Name rührt von der Analogie zu optischen Linsen und der wirkenden Kraft, der Gravitation, her. Grundsätzlich wird dabei das Licht… …   Deutsch Wikipedia

  • Gravitationslinseneffekt — (Animation) Das Einsteinkreuz …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”