Intergalaktisk

Intergalaktisk is a Swedish adjective meaning “between galaxies” or “relating to the space between galaxies.” In astronomy it is used to describe regions, processes, and objects that lie outside the gravitational influence of individual galaxies.

The intergalactic medium (IGM) is the primary context for the term. It consists largely of ionized hydrogen and helium and is extremely tenuous, with densities around 10^-6 to 10^-4 particles per cubic centimeter (roughly 1 to 100 particles per cubic meter). This diffuse gas forms part of the cosmic web, a network of filaments that connect galaxies and clusters across vast distances.

In addition to its scientific usage, intergalaktisk appears in broader, often fictional, contexts to describe phenomena, structures, or events that span multiple galaxies—such as intergalactic travel, trade, or conflict. In scholarly writing, more precise terms like intergalactic medium or intergalactic space are commonly employed, while intergalaktisk may appear in descriptive or literary passages.

Etymology is straightforward: inter- means “between,” and galaktisk derives from galaxis, itself from Greek galaktikos meaning “milky,” tied to the Milky Way. The word reflects the scale of space beyond a single galaxy and its place in languages that describe the broader cosmos.

Related concepts include interstellar (between stars), galaxy, and the cosmic web that underpins the large-scale structure of the universe.