What you can do

Look up a relation

2,041 curves from 22 simulations and 117 observational and empirical sources on one plot, each with its source and its definitions.

Check your own run

Paste your curve; get offsets against the published curves it can fairly be compared with. Nothing leaves your browser.

Turn the physics dials

Four feedback dials each for IllustrisTNG and SIMBA, from 2,054 CAMELS simulations: what moves, what stays apart.

Take the data

CSV, JSON, BibTeX and a Python loader. CC BY 4.0.

What it has found

• Only 4% of 2,567 pairs of curves from different simulations measure the same thing in the same way.
• Putting 9 simulations' stellar mass functions on the same footing did not measurably shrink the disagreement between them.
• We could not show that simulations disagree more about the early Universe than the later one (the spread is 2.2 times larger, but our test did not pass); retuning four dials per code brings two codes from 0.22 to 0.08 dex apart.
• After the best possible retuning of each code's four dials, IllustrisTNG and SIMBA are still 4.8 noise units apart over all properties at once.

Each result was fixed by a rule written before the answer was computed, except the first, which is descriptive. The studies give the rules, the checks made afterwards and the limits.

How far to trust it

• Not peer reviewed; one maintainer (see Methods). 55% of simulation curves were read from published figures and are never used to rank anything; where authors publish a table, use theirs.
• The dials results are for two codes at CAMELS resolution, not for simulations in general.
• Nobody outside the project is known to have used it yet. Used it? Say so.

Cite

Bhatia, S. (2026). sim-highline: curated galaxy scaling relations from cosmological simulations (v0.24.0). Zenodo. https://doi.org/10.5281/zenodo.23217259. Please also cite the original paper of every curve you use.

Wrong or confusing? Tell us in two sentences.