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S4G and ATLAS3D: a few thousand galaxies from published decompositions, and ellipticals

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Assessment

Difficulty
5/5
Estimated time
Over a week
Newbie friendliness
12/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Active
Tech stack
javascript
Domain
data, data-visualization

Research direction

Start with the SPARC pipeline this extends: tools/sparc/ and the parametric-galaxy work in #221 and PR #223, plus the point-population engine in #98 that the far points should move onto. The work is a new build script with NED/SIMBAD cross-matching and sourced defaults for S4G and ATLAS3D, not a small edit. Done means about 2,500 galaxies rendered from their published decompositions, labelled on e, searchable, and holding frame rate under ?perf=1.

Written by the indexing model from the issue text.

Description

enhancement track:deep-sky

Part of #117 (deep sky). This extends SPARC's parametric galaxies (#221, PR #223) to a few thousand galaxies, and adds the elliptical family that SPARC lacks.

What

  • S4G, the Spitzer Survey of Stellar Structure in Galaxies (Sheth et al. 2010):
    • about 2,350 nearby galaxies (d < 40 Mpc) at 3.6 µm, SPARC's band, so the mapping is the same;
    • Salo et al. 2015 (ApJS 219, 4) publish multi-component decompositions (Sérsic bulge, exponential disc with breaks, bar, nucleus), which prime #223's glow model directly;
    • S4G's early-type extension covers S0s and ellipticals.
  • ATLAS3D (Cappellari et al. 2011): 260 early-type galaxies with structural and kinematic parameters (fast or slow rotators). It's the source for a Sérsic-profile family of ellipticals on the same glow model, which #223 didn't need.

How

  • Pipeline: the same as #223's tools/sparc/:
    • a build script;
    • cross-matches against NED and SIMBAD for positions, PAs and colours;
    • type-driven defaults, with sources, for what isn't measured.
  • Overlaps: SPARC's rows, which have rotation curves, win where both catalogues have a galaxy. OpenNGC adds names only.
  • Levels of detail: as in #223 (far points, impostors, the full march up close). With a few thousand galaxies, the far points should move onto the point-population engine (#98).

Done when

  • About 2,500 galaxies (spirals, S0s and ellipticals) are each drawn from their own published decomposition, in exposure units.
  • They're labelled on e, searchable and flyable.
  • Ellipticals look like ellipticals.
  • The frame rate holds (?perf=1).

Related: SPARC galaxies #221 / PR #223; globulars #228 (Harris, plus Baumgardt); deep-sky objects from OpenNGC #229; nearby galaxies #230; S4G and ATLAS3D #231; large-scale structure #232; catalogues as scene features, analysis as apps #233; galactic dynamics #106; the Milky Way #116.

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Dominant language
JavaScript
Stars
55
Forks
4
Avg merge
10h 12m
Merged PRs (30d)
134

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