Data & source
Data: Gravitational Wave Open Science Center,
cumulative Gravitational-Wave Transient Catalog (GWTC-1 through GWTC-5.0),
LIGO Scientific / Virgo / KAGRA collaborations — open data, CC BY 4.0 ·
fetched —.
Scope: the 282 catalog entries that carry a published pair of
source-frame masses, out of 391 entries in all. The most
recent release also lists candidates whose parameters have not been published yet; those
are left out rather than guessed, so this is the detections whose masses are known,
not every detection. Every event drawn clears the catalogs' own confident threshold
(probability of astrophysical origin above 0.5), and a few sit only just above it.
Each mass is the median of a probability distribution, not a measurement: the cross
through every dot is the 90% credible interval, and on the faintest signals it is wider
than the dot is far from its neighbours. Masses are source-frame (the redshift is
divided out). Dot size is the network signal-to-noise ratio — how loudly the signal
arrived, which depends as much on distance and on which detectors were running as on the
collision itself. Distance is luminosity distance in megaparsecs. The catalog is
detection-limited by construction: loud, nearby, heavy mergers are easy to hear and
quiet ones are not, so this is what the instruments could reach, not what the universe
contains.