Lyman-break galaxy

High school (ages 12+)
Space & Astronomy

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Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/lyman-break-galaxy

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the object classification?Galaxies
2. What is the redshift range?Typically z > 2, extending to z ~ 10 or higher
3. What is a Lyman‑break galaxy?A Lyman‑break galaxy is a very old, very far‑away galaxy that we can see from the early universe. It is special because its light has a sudden drop at a particular ultraviolet wavelength, called the Lyman‑alpha line.
4. Why do Lyman‑break galaxies have a "break" in their light?The drop, or "break", happens because neutral hydrogen gas in space absorbs the energetic ultraviolet light before it reaches us. This absorption makes the galaxy look much fainter just below that wavelength.

Intergalactic Medium (IGM): The diffuse gas and plasma that exists between galaxies in the universe.
Lyman-alpha Emission: Electromagnetic radiation emitted by hydrogen atoms when an electron transitions to the n=1 energy level.
Photometric Redshift: An estimation of a galaxy's redshift based on its colors across different photometric bands.
Cosmic Web: The large-scale structure of the universe, characterized by filaments, clusters, and voids of galaxies and dark matter.