The Event Horizon Telescope needs a 22 micro-arcsecond resolution to view the event horizon regions around black holes. If the average wavelength is a 1.3 mm radio wave, (A) what is the diameter of the effective primary objective? (B) How can astronomers build a telescope this big? Defend your answers.

Answer :

Answer:

14869817.395 m

Explanation:

[tex]\theta[/tex]=22 microarcsecond

λ = Wavelength = 1.3 mm

Converting to radians we get

[tex]22\times 10^{-6}\frac{\pi}{180\times 3600}\ radians[/tex]

From Rayleigh Criterion

[tex]\theta=1.22\frac{\lambda}{D}\\\Rightarrow D=1.22\frac{\lambda}{\theta}\\\Rightarrow D=1.22\frac{1.3\times 10^{-3}}{22\times 10^{-6}\frac{\pi}{180\times 3600}}\\\Rightarrow D=14869817.395\ m[/tex]

Diameter of the effective primary objective is 14869817.395 m

It is not possible to build one telescope with a diameter of 14869817.395 m. But, we need this type of telescope. So, astronomers use an array of radio telescopes to achieve a virtual diameter in order to observe objects that are the size of supermassive black hole's event horizon.

Other Questions