Sample interview questions: Can you explain the concept of cosmic rays and their role in star and planet formation?
Sample answer:
Cosmic Rays: Origin, Propagation, and Role in Star and Planet Formation
- Nature and Origin of Cosmic Rays:
- Cosmic rays are energetic subatomic particles that originate from various astrophysical sources.
- Primary cosmic rays include protons (hydrogen nuclei), alpha particles (helium nuclei), and a small fraction of heavier atomic nuclei.
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They originate from various sources, including supernova explosions, active galactic nuclei, and stellar winds from massive stars.
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Propagation and Interactions:
- Cosmic rays travel through interstellar space and interact with the interstellar medium (ISM).
- They undergo various interactions, including collisions with gas atoms and molecules, producing secondary cosmic rays.
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The rate of interaction depends on the energy of the cosmic ray and the density of the ISM.
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Cosmic Rays in Star Formation:
- Cosmic rays play a crucial role in star formation by influencing various physical processes.
- They inject energy into molecular clouds, triggering the collapse of dense gas regions and the formation of protostars.
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They contribute to the ionization of the ISM, affecting the chemistry and cooling mechanisms within molecular clouds.
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Cosmic Rays in Planet Formation:
- Cosmic rays can influence the formation of planets by modifying the protoplanetary disk structure and chemistry.
- They ionize the disk gas, reducing the collisional damping and allowing dust grains to drift more freely.
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Cosmic rays can also contribute to the heating of the disk, affecting its vertical structure and… Read full answer