The Einstein Cross (Q2237+030 or QSO 2237+0305) is a gravitationally lensedquasar that sits directly behind the centre of the galaxy ZW 2237+030, called Huchra's Lens. Four images of the same distant quasar (plus one in the centre, too dim to see) appear in the middle of the foreground galaxy due to strong gravitational lensing.[1][2] This system was discovered by John Huchra and coworkers in 1985, although at the time they only detected that there was a quasar behind a galaxy based on differing redshifts and did not resolve the four separate images of the quasar.[3]
While gravitationally lensed light sources are often shaped into an Einstein ring, due to the elongated shape of the lensing galaxy and the quasar being off-centre, the images form a peculiar cross-shape instead.[4]
Other "Einstein crosses" have been discovered[5] (see image below of one of them).
The quasar's redshift indicates that it is located about 8 billion light years from Earth, while the lensing galaxy is at a distance of 400 million light years. The apparent dimensions of the entire foreground galaxy are 0.87 × 0.34 arcminutes,[6] while the apparent dimension of the cross in its centre accounts for only 1.6 × 1.6 arcseconds.
The Einstein Cross can be found in Pegasus at 22h 40m 30.3s, +3° 21′ 31″.
Amateur astronomers are able to see some of the cross using telescopes; however, it requires extremely dark skies and telescope mirrors with diameters of 18 inches (46 cm) or greater.[7]
The individual images are labelled A through D (i.e. QSO 2237+0305 A), the lensing galaxy is sometimes referred to as QSO 2237+0305 G.
Galleryedit
Another lensed quasar, HE0435-1223 in Eridanus, and its surroundings[8]
^NASA and ESA (September 13, 1990). . HubbleSite. Archived from the original on 19 December 2005. Retrieved July 25, 2006.
^Drakeford, Jason; Corum, Jonathan; Overbye, Dennis (March 5, 2015). "Einstein's Telescope - video (02:32)". The New York Times. Retrieved December 27, 2015.
^Huchra, J.; et al. (1985). "2237 + 0305: A new and unusual gravitational lens". Astronomical Journal. 90: 691–696. Bibcode:1985AJ.....90..691H. doi:10.1086/113777.
^"How does gravitational lensing account for Einstein's Cross?". physics.stackexchange.com. Retrieved 2016-06-26.
^"A new Einstein cross is discovered". phys.org. Retrieved 2019-11-13.
einstein, cross, q2237, 2237, 0305, gravitationally, lensed, quasar, that, sits, directly, behind, centre, galaxy, 2237, called, huchra, lens, four, images, same, distant, quasar, plus, centre, appear, middle, foreground, galaxy, strong, gravitational, lensing. The Einstein Cross Q2237 030 or QSO 2237 0305 is a gravitationally lensed quasar that sits directly behind the centre of the galaxy ZW 2237 030 called Huchra s Lens Four images of the same distant quasar plus one in the centre too dim to see appear in the middle of the foreground galaxy due to strong gravitational lensing 1 2 This system was discovered by John Huchra and coworkers in 1985 although at the time they only detected that there was a quasar behind a galaxy based on differing redshifts and did not resolve the four separate images of the quasar 3 Einstein CrossObservation data Epoch J2000 ConstellationPegasusRight ascension22h 40m 30 3sDeclination 3 21 31 Redshift1 695Distance8 000 000 000 ly 2 500 000 000 pc TypeLeQApparent dimensions V less than 2 Apparent magnitude V 16 78Other designationsLEDA 69457 Z 378 15See also Quasar List of quasars While gravitationally lensed light sources are often shaped into an Einstein ring due to the elongated shape of the lensing galaxy and the quasar being off centre the images form a peculiar cross shape instead 4 Other Einstein crosses have been discovered 5 see image below of one of them Contents 1 Details 2 Gallery 3 See also 4 References 5 External linksDetails editThe quasar s redshift indicates that it is located about 8 billion light years from Earth while the lensing galaxy is at a distance of 400 million light years The apparent dimensions of the entire foreground galaxy are 0 87 0 34 arcminutes 6 while the apparent dimension of the cross in its centre accounts for only 1 6 1 6 arcseconds The Einstein Cross can be found in Pegasus at 22h 40m 30 3s 3 21 31 Amateur astronomers are able to see some of the cross using telescopes however it requires extremely dark skies and telescope mirrors with diameters of 18 inches 46 cm or greater 7 The individual images are labelled A through D i e QSO 2237 0305 A the lensing galaxy is sometimes referred to as QSO 2237 0305 G Gallery edit nbsp Another lensed quasar HE0435 1223 in Eridanus and its surroundings 8 nbsp Hubble Space Telescope captures Einstein Cross See also editCloverleaf Quasar Einstein ring Chwolson ring Gravitational lensing Quasar SN Refsdal Twin QuasarReferences edit NASA and ESA September 13 1990 The Gravitational Lens G2237 0305 HubbleSite Archived from the original on 19 December 2005 Retrieved July 25 2006 Drakeford Jason Corum Jonathan Overbye Dennis March 5 2015 Einstein s Telescope video 02 32 The New York Times Retrieved December 27 2015 Huchra J et al 1985 2237 0305 A new and unusual gravitational lens Astronomical Journal 90 691 696 Bibcode 1985AJ 90 691H doi 10 1086 113777 How does gravitational lensing account for Einstein s Cross physics stackexchange com Retrieved 2016 06 26 A new Einstein cross is discovered phys org Retrieved 2019 11 13 LEDA 69457 SIMBAD Centre de donnees astronomiques de Strasbourg Retrieved 12 February 2017 Crinklaw Greg Focus on Einstein s Cross Retrieved 2013 06 29 Cosmic lenses support finding on faster than expected expansion of the Universe www spacetelescope org Retrieved 27 January 2017 External links editSimbad Information about Einstein s Cross on Skyhound com Einstein s Cross core Einstein s Cross by Jay Reynolds Freeman Photo of the Einstein Cross at Astronomy Picture of the Day March 11 2007 Google Sky Portals nbsp Astronomy nbsp Stars nbsp Spaceflight nbsp Outer space nbsp Solar System Retrieved from https en wikipedia org w index php title Einstein Cross amp oldid 1204651280, wikipedia, wiki, book, books, library,
