The Gravitational Lens System UM673

This photo shows a newly discovered gravitational lens system and the galaxy that causes this effect. To the left are seen the two lensed stellar-like images of the quasar UM673; the magnitude of the brighter (A) is 17 and that of the fainter (B) is 19. The angular distance between A and B is 2.2 arcsec., i.e. approximately equal to one thousandth the angle under which we see the solar (or lunar) disk from Earth. The intervening galaxy (C) which is responsible for the gravitational bending of the quasar light, and thus for the formation of the two images of the same object, is seen on the right, together with another galaxy (D), possibly a member of the same cluster of galaxies. The right-hand picture was computer enhanced and the two images of the quasar have been removed in order to show better the faint lensing galaxy. This is why the background is rather uneven and the individual picture elements (pixels) are visible. The CCD frame was obtained with the EFOSC instrument attached to the Cassegrain focus of the ESO 3.6m telescope. One pixel = 0.338 arcsec. The scale is indicated. North is up and East to the left. (ESO Press Release eso8715; BW)

 

This photo shows a newly discovered gravitational lens system and the galaxy that causes this effect. To the left are seen the two lensed stellar-like images of the quasar UM673; the magnitude of the brighter (A) is 17 and that of the fainter (B) is 19. The angular distance between A and B is 2.2 arcsec., i.e. approximately equal to one thousandth the angle under which we see the solar (or lunar) disk from Earth. The intervening galaxy (C) which is responsible for the gravitational bending of the quasar light, and thus for the formation of the two images of the same object, is seen on the right, together with another galaxy (D), possibly a member of the same cluster of galaxies. The right-hand picture was computer enhanced and the two images of the quasar have been removed in order to show better the faint lensing galaxy. This is why the background is rather uneven and the individual picture elements (pixels) are visible. The CCD frame was obtained with the EFOSC instrument attached to the Cassegrain focus of the ESO 3.6m telescope. One pixel = 0.338  0.338 arcsec. The scale is indicated. North is up and East to the left. (ESO Press Release eso8715; BW)

Credit:

 

About the Image

Id:eso8715a
Type:Observation
Release date:22 October 1987
Related releases:eso8715
Size:1782 x 1260 px

About the Object

Name:UM673
Type:• Early Universe : Galaxy : Type : Gravitationally Lensed
• Early Universe : Galaxy : Activity : AGN : Quasar
• X - Galaxy Clusters
• X - Galaxies
Distance:z=2.731 (redshift)

Image Formats

Large JPEG
862.0 KB
Screensize JPEG
307.2 KB

Colours & filters

BandTelescope
OpticalESO 3.6-metre telescope
EFOSC

 

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