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Research draft

interstellar medium

vr.tr.interstellar-medium · PHY.SPC

Let an agent describe the interstellar medium by phase, composition and role in star formation, with sourced observations.

Thing Registry Physical world and living systems

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent describe the interstellar medium by phase, composition and role in star formation, with sourced observations.

The matter and radiation in the space between star systems in a galaxy, including gas, dust, cosmic rays and magnetic fields, from cold molecular clouds to hot ionised regions.

What it is for: The raw material of stars and the recycling medium of galaxies.

It can be observe it across the spectrum; measure density and temperature; map it; study star formation.

Distinguishing features

Matter between stars

Multiple phases

Mostly hydrogen and helium with dust

Site of star formation

What it looks like

Mostly invisible; seen as nebulae, dark clouds and in radio and infrared maps.

Physical character

average density: about 1 atom per cm3 - varies hugely by phase

temperature: 10 K to millions of K kelvin - phases

How it is recognised

Dark dust lanes

Emission and reflection nebulae

Radio maps of hydrogen

Related models

contains - structures

nebula

is part of - component

galaxy

forms - star formation

star

is studied by - field

astronomy

In practice

Families and kinds

molecular clouds

cold and warm neutral medium

warm and hot ionised medium

photodissociation regions

dust

Failure modes and hazards

Confusing phases

Overstating certainty of models

Also called

region of interstellar spacePhotodissociation region

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.interstellar-medium

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Phases Components.

Phases differ greatly.

Phase

Molecular to hot.

Phase

Phase.

  1. Which phase of the medium is meant? definition
  2. What are its density and temperature? measurement

Composition

Gas and dust.

Composition

Composition.

  1. What is its composition? measurement
  2. How was it measured? provenance
Observation How seen.

Multiwavelength observation.

Methods

Radio, infrared.

Methods

Observation methods.

  1. Which wavelengths reveal it? definition
  2. Which surveys map it? provenance

Dust

Extinction.

Dust

Dust effects.

  1. How does dust affect observations? definition
  2. How is it corrected? action
Role Star formation.

The medium feeds stars.

Star formation

Collapse.

Formation

Star formation.

  1. Where is star formation happening in it? provenance
  2. At what rate? measurement

Recycling

Feedback.

Recycling

Recycling.

  1. How do stars return material to it? definition
  2. What is the evidence? provenance
Science Models.

Models are uncertain.

Models

Theory.

Models

Models.

  1. Which models describe it? provenance
  2. Where do they disagree? boundary

Communication

Accuracy.

Communication

Clear explanation.

  1. How can it be explained simply? action
  2. Which images are false colour? boundary

What the second pass must settle

  • Should phases be separate entries?
  • How should survey maps be linked?
  • How should models be marked?