Table of Contents
How does a gravitational lens work?
What Is Gravitational Lensing? A gravitational lens can occur when a huge amount of matter, like a cluster of galaxies, creates a gravitational field that distorts and magnifies the light from distant galaxies that are behind it but in the same line of sight. The effect is like looking through a giant magnifying glass.
How was gravitational lens discovered?
The first gravitational lens was discovered in 1979, when two quasars were discovered very close to each other in the sky and with similar distances and spectra. The two quasars were actually the same object whose light had been split into two paths by the gravitational influence of an intervening galaxy.
Who invented Einstein’s ring?
The first Einstein ring was discovered by Hewitt et al. (1988), who observed the radio source MG1131+0456 using the Very Large Array. This observation saw a quasar lensed by a nearer galaxy into two separate but very similar images of the same object, the images stretched round the lens into an almost complete ring.
What is gravitational deflection?
Abstract. Gravitational deflection of light ray is one of the famous predictions of Einstein’s general theory of relativity. Introduction Light around a massive object, such as sun, is curved. This is due to the gravity of that massive body and this phenomenon is known as gravitational bending.
What does gravitational lens mean in astronomy Dictionary?
What does gravitational-lens mean? A massive object whose gravitational field redirects or bends light rays. (noun) Dictionary ! Menu. (astronomy) A massive body that produces distorted, magnified or multiple images of more distant objects when its gravitational field bends the path of light rays. noun. 0. 0.
Do Gravitational lenses have a focus point?
Consequently, a gravitational lens has no single focal point, but a focal line. The term “lens” in the context of gravitational light deflection was first used by O.J. Lodge, who remarked that it is “not permissible to say that the solar gravitational field acts like a lens, for it has no focal length”.
Which lens is the second lens that magnifies the object?
The first lens catches light rays from the distant object and makes a focused image a short distance behind the lens. This lens is called the objective, because it’s nearest to the object you’re looking at. The second lens picks up that image and magnifies it, just like a magnifying glass magnifies an image on paper. It’s called the eyepiece .
What is gravitational lensing?
Gravitational lensing is useful to cosmologists because it is directly sensitive to the amount and distribution of dark matter. This is because the amount of light bending is sensitive only to the strength of the gravitational field it passes through*, which is mostly generated by the mass of the dark matter in the Universe.