Quasars Emit Significant Amounts of Radiation from the Lyman-Alpha Transition

question 46

Multiple Choice

Quasars emit significant amounts of radiation from the Lyman-alpha transition. When the spectrum is observed on Earth, it is found that the Lyman-alpha line is accompanied by many absorption lines, called the Lyman-alpha forest. What is the origin of these lines? See Figure 18-5 in the text.

• A) The absorption lines are caused by the rotation of the quasar. Different parts of the quasar thus give rise to Lyman-alpha lines with different Doppler shifts.
• B) The absorption lines are the result of gravitational lensing by objects between the quasar and Earth.
• C) The emitted Lyman-alpha radiation is absorbed by many gas clouds between the quasar and Earth. The lines are receding at various velocities and thus are absorbed at different Doppler-shifted wavelengths.
• D) Because the quasar's jets are aimed at various directions, the jet plasma has Doppler shifts that are different from those of the quasar itself. The result is a variety of Lyman-alpha wavelengths in the spectrum received on Earth.

Understand the importance of self-awareness and self-examination in the helping profession.

Recognize the role of personal motivations and influences in choosing a helping career.

Identify effective strategies for coping with anxiety, uncertainty, and challenges in the helping profession.

Appreciate the significance of cultural competence and diversity awareness in effective helping.

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Definitions:

Independent

The state of being free from outside control or not influenced by others, often used in the context of research to describe variables not affected by others.

In-Group Bias

The tendency to favor individuals within our own group over those from outside groups.

Out-Group Bias

The tendency to have negative views or prejudices towards people who are perceived as belonging to a different group than one's own.

Discrimination

Unjust or prejudiced treatment of different categories of people, especially on the grounds of race, age, or sex.