Which was used to create the first image of a black hole?(1 point)
Responses
a radio waves from matter at the edge of the black hole
b visible light from the black hole
c ultraviolet light from objects in the black hole
d x-rays from inside the black hole
a radio waves from matter at the edge of the black hole
a radio waves from matter at the edge of the black hole
The correct answer is option (a) - radio waves from matter at the edge of the black hole.
To arrive at this answer, we need to understand the process behind creating an image of a black hole.
The Event Horizon Telescope (EHT) project was responsible for capturing the first-ever image of a black hole. Here's how they did it:
1. Radio Telescopes: The EHT team used a network of radio telescopes placed around the world. These telescopes formed a virtual telescope the size of the Earth, allowing them to observe the black hole in great detail.
2. Radio Waves: Instead of using visible light or other forms of electromagnetic radiation, the EHT project focused on radio waves emitted by matter near the black hole's event horizon. The event horizon is the boundary beyond which nothing, not even light, can escape the gravitational pull of the black hole.
3. Accretion Disk: As matter falls towards a black hole, it forms a disk-like structure called an accretion disk. This disk emits powerful radio waves due to friction and intense magnetic fields. The black hole's gravity compresses and accelerates the particles, generating the radio emissions.
4. Interferometry: By combining the signals received by the network of telescopes using a technique called Very Long Baseline Interferometry (VLBI), the EHT project was able to create a high-resolution image of the black hole's shadow, which is visible because it blocks the radio waves emitted from the accretion disk.
Therefore, the image of the black hole was created using radio waves from matter at the edge of the black hole, making option (a) the correct answer.