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In 2009, weak gravitational lensing was used to extend the mass-X-ray-luminosity relation to older and smaller structures than was previously possible to improve measurements of distant galaxies. [29] As of 2013 the most distant gravitational lens galaxy, J1000+0221, had been found using NASA's Hubble Space Telescope.
In weak gravitational lensing, the Jacobian is mapped out by observing the effect of the shear on the ellipticities of background galaxies. This effect is purely statistical; the shape of any galaxy will be dominated by its random, unlensed shape, but lensing will produce a spatially coherent distortion of these shapes.
The geometry of gravitational lenses. In the following derivation of the Einstein radius, we will assume that all of mass M of the lensing galaxy L is concentrated in the center of the galaxy. For a point mass the deflection can be calculated and is one of the classical tests of general relativity.
The key difference between an embedded lens and a traditional lens is that the mass of a standard lens contributes to the mean of the cosmological density, whereas that of an embedded lens does not. Consequently, the gravitational potential of an embedded lens has a finite range, i.e., there is no lensing effect outside of the void.
The effects of foreground galaxy cluster mass on background galaxy shapes. The upper left panel shows (projected onto the plane of the sky) the shapes of cluster members (in yellow) and background galaxies (in white), ignoring the effects of weak lensing. The lower right panel shows this same scenario, but includes the effects of lensing.
Strong gravitational lensing is a gravitational lensing effect that is strong enough to produce multiple images, arcs, or Einstein rings. Generally, for strong lensing to occur, the projected lens mass density must be greater than the critical density , that is Σ c r {\displaystyle \Sigma _{cr}} .
Abell 2218 was used as a gravitational lens to discover the most distant known object in the universe as of 2004. The object, a galaxy some 13 billion years old, is seen from Earth as it would have been just 750 million years after the Big Bang. [3] The color of the lensed galaxies is a function of their distances and types.
These arcs or deformations are mirages caused by gravitational lensing of distant galaxies by the massive galaxy cluster located between the observer and the magnified galaxies. [3] [8] This cluster shows an apparent magnitude of +22. In 2002, astronomers used this lensing effect to discover a galaxy, HCM-6A, 12.8 billion light years away from ...