← Back to catalogue
Published

galaxy

vr.tr.galaxy · thing-q318

Let an agent describe galaxies by type, distance, size and designation, and handle catalogue cross-identification.

Thing Registry Physical world and living systems PHY.SPC
Bundle → Layer → Finding → QuestionsClassifiersWhat it isWhy it existsDistinguishing featuresWhat robots and AI may and may not doMoral aspectsOwnersLinks to other meta-modelsIdentity and identifiersDirect propertiesRecognitionCapabilities and actionsHazards and failure modesStandards and interfacesContext of useSources

Bundle → Layer → Finding → Questions Filled

4 bundles · 8 layers · 8 findings · 16 questions

Identity Which galaxy.

Designations

Catalogue ids.

Designations

Designations and names.

  1. Which designations identify this galaxy? provenance
  2. Is it confirmed or a candidate? boundary

Type

Morphology.

Morphology

Morphological type.

  1. What morphological type is it? definition
  2. Is it active? definition
Distance and size How far and how big.

Distance

Method and value.

Distance

Distance and method.

  1. How far away is it, by which method? measurement
  2. Which cosmology was assumed? provenance

Size and mass

Diameter, stars, mass.

Size

Size and mass.

  1. What are its size and mass? measurement
  2. How much is dark matter? measurement
Contents What it contains.

Stars and gas

Populations.

Populations

Stellar populations and gas.

  1. What stellar populations and gas does it contain? measurement
  2. Is it forming stars? measurement

Nucleus

Central black hole.

Nucleus

The central black hole.

  1. Does it have a supermassive black hole, of what mass? measurement
  2. Is the nucleus active? definition
Environment Neighbours and interactions.

Group

Cluster or group.

Membership

Group membership.

  1. Which group or cluster is it part of? definition
  2. Is it interacting with neighbours? definition

Observation

Data sources.

Data

Surveys and archives.

  1. Which surveys have observed it? provenance
  2. How can it be observed by amateurs? action

Classifiers Filled

Family
Thing Registry
Category
Physical world and living systems
Entry kind
thing
Plane
PHY
Domain
PHY.SPC
Other names and narrower kinds
radio galaxy, field galaxy, dark galaxy, luminous infrared galaxy, possible galaxy, binary galaxy, X-shaped radio galaxy, Lyman-alpha emitter, star-forming galaxy, intergalactic, brightest cluster galaxy, low-surface-brightness galaxy

What it is Filled

A gravitationally bound system of stars, stellar remnants, gas, dust and dark matter, ranging from ultra-faint dwarf galaxies with far fewer than a million stars to giants of trillions.

Why it exists Filled

Let an agent describe galaxies by type, distance, size and designation, and handle catalogue cross-identification.

Distinguishing features Filled

  • Gravitationally bound with dark matter
  • Much larger than star clusters
  • Classified by the Hubble sequence and activity
  • Our own galaxy is the Milky Way

What robots and AI may and may not do Filled

Must not

  • Merge different galaxies with similar designations into one record.
  • Give redshift distances without stating the cosmology.
  • Present speculative findings as established.

Only with a human decision

  • Correcting catalogue records that others rely on.

May

  • Report galaxy designations, positions and properties from astronomical catalogues.
  • State the cosmological model used when converting redshift to distance.

Moral aspects Filled

  • Public understanding of the universe depends on honest reporting of uncertainty.

Who is affected

  • The public
  • Astronomers

Owners Filled

Steward

Nobody owns a galaxy; the astronomical community catalogues them.

Master systems

  • Extragalactic catalogues of the astronomical community

Links to other meta-models Filled

parent

  • Q249389 - registry parent class

related

  • astronomical object - large-scale system
  • galaxy cluster - larger structures
  • supermassive black hole - at the centre of most large galaxies

contains

  • star and black hole - components

What else AI and robots need to interact with it Filled

Identity and identifiers required Filled

  • Vercy registry: vr.tr.galaxy
  • Wikidata: Q318 (https://www.wikidata.org/wiki/Q318)
  • Messier and NGC numbers: M or NGC plus number classic catalogues
  • PGC number: numeric Principal Galaxies Catalogue

Direct properties required Filled

  • stars: 10^6 to 10^13 stars
  • diameter: 1000-500000+ light years
  • distance to Andromeda: 2.5 million light years

Recognition required Filled

  • Extended, not point-like, sources
  • Morphology: spiral, elliptical, lenticular, irregular
  • Designations such as M31, NGC 224, PGC numbers
  • A fuzzy patch in a telescope; in images, spiral arms, ellipsoids or irregular shapes; the Milky Way is seen from inside as a band of light.

Capabilities and actions required Filled

  • observe it, across the spectrum
  • classify it, by morphology and activity
  • measure its distance and redshift
  • catalogue it, with designations

Hazards and failure modes required Filled

  • Merging different galaxies with similar designations
  • Using redshift distances without stating cosmology

Standards and interfaces required Filled

  • IAU nomenclature

Context of use required Filled

  • Galaxies are the building blocks of the large-scale universe; studying them explains cosmic history.
  • spiral, barred spiral, elliptical, lenticular, irregular
  • dwarf galaxies
  • active galaxies: radio galaxies, quasars
  • luminous infrared galaxies
  • interacting and binary galaxies

Sources Filled

  1. Wikidata item Q318: galaxy - identity and sense of the item
  2. Wikipedia: Galaxy - general description of the item

Open questions

  • Should named galaxies be instances with cross-identifiers?
  • How should distance methods be recorded?
  • How should uncertain galaxy candidates be marked?

Machine files

Card as JSON Specification Card backlog vercy.card/1

Provenance

thing registry research (pass 2) · unreviewed

Built from: models/things/publications/thing-q318/spec.json