Radiation from Active Galactic Nuclei (AGN) is the main source for which cosmic background(s)? (Select all that apply)
A. X-ray Background
B. Infrared Background
C. Radio Background
D. Gamma-ray Background
A, B, C, D.
Radiation from Active Galactic Nuclei (AGN) is the main source for the following cosmic backgrounds:
1. Cosmic X-ray Background (CXB): AGN emit significant amounts of X-ray radiation, and their cumulative emission forms a diffuse X-ray background observed throughout the universe.
2. Cosmic Infrared Background (CIB): AGN can also contribute to the infrared background radiation due to their emission of thermal radiation from dust and gas in their surroundings.
So, the correct selections are:
- Cosmic X-ray Background (CXB)
- Cosmic Infrared Background (CIB)
To determine the main sources of cosmic backgrounds, including those related to radiation from Active Galactic Nuclei (AGN), we can consult relevant scientific literature or astrophysics resources.
To begin, we can search for information on the primary cosmic backgrounds. Some widely known cosmic backgrounds include:
1. Cosmic Microwave Background (CMB): This is the oldest radiation present in the universe, dating back to roughly 380,000 years after the Big Bang. It is predominantly composed of microwave radiation.
2. Cosmic X-ray Background (CXB): This background radiation is in the X-ray wavelength range and comes from various sources, including AGN, star-forming galaxies, and galaxy clusters.
3. Cosmic Infrared Background (CIB): This background consists of infrared radiation and originates from the collective emission of stars, galaxies, and AGN.
Now, let's focus on the role of AGN radiation as a source for cosmic backgrounds. AGN are known to be powerful emitters of radiation across different wavelengths, including radio waves, optical light, X-rays, and gamma-rays. Therefore, AGN can contribute to multiple cosmic backgrounds.
Based on this information, the cosmic backgrounds for which radiation from AGN could be a main source are:
- Cosmic X-ray Background (CXB): AGN contribute significantly to the X-ray background due to their emission of high-energy X-rays.
- Cosmic Infrared Background (CIB): AGN radiation at various wavelengths, including infrared, contributes to the overall CIB.
Therefore, the correct answer is:
- Cosmic X-ray Background (CXB)
- Cosmic Infrared Background (CIB)