Black hole - frequencies used for viewing

[isha89]

Hey,

In space missions why do they choose different frequencies for viewing stars?

For example why do they choose both 43 GHz and 230 GHz to view a black hole?


Cheers!

 

[Drakkith]

Different frequencies are emitted by different types of objects. They also can penetrate different things in space, such as visible light being blocked by dust while radio-infrared is able to penetrate it. I can't say why 43 ghz and 230 ghz is used to view certain black holes, but I assume it's either because much of rest of the spectrum is blocked or because the black hole emits radiation specifically at these frequencies.