Gas phases of the interstellar medium
The interstellar medium contains ionized, atomic and molecular gas alongside dust.
Key knowledge
The interstellar medium contains ionized, atomic and molecular gas alongside dust. Different tracers reveal different components: ionized regions emit recombination lines, neutral hydrogen can be traced by 21-centimetre emission, and molecular transitions trace suitable cold gas. One observing band does not reveal the whole medium.
Conditions and scope
- A tracer's intensity depends on excitation, optical depth and abundance as well as gas amount.
- The tracer list is representative; ionization and temperature are not uniform within a phase label.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Read ionized nebulae, 21-cm neutral hydrogen and molecular-cloud tracer paragraphs; no fixed phase fractions or single-tracer mass conversion asserted.
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Entry details
Permanent link to this entry ↗- Record identity
- uni-cosmos-interstellar-medium
- Revision
- core.1
- Structured reference record
- University core expansion