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How to Explore Pulsar Timing Array 3D Explorer
Open the Pulsar Timing Array 3D Explorer, sweep the separation slider, and watch the gold reference pulsar and magenta probe pulsar's live-computed Hellings-Downs correlation rise, dip negative, and climb back up.
- Open https://freetoolonline.com/space-3d/pulsar-timing-array.html and wait for Earth, the pulsar array, and the highlighted pair to render.
- Drag the separation slider from 0 toward 180 degrees and watch the magenta probe pulsar move along the dashed arc away from the gold reference pulsar.
- Press "Play sweep" to run the full 0-to-180-degree cycle automatically.
- Check "Show correlation-curve chart" to reveal the inline chart plotting the correlation across every angle, with a marker at your current position.
- Read the facts panel for the live Hellings-Downs correlation number and whether the pair is positively correlated, anti-correlated, or near zero.
- Drag to orbit the scene and scroll or pinch to zoom for a better view of the array.
Key published figures
| Figure | Value |
|---|---|
| Hellings-Downs correlation at 0 degrees | 0.500 |
| Hellings-Downs correlation at 180 degrees | 0.250 |
| NANOGrav 15-year data set | 68 millisecond pulsars |
| 2023 background amplitude | about 2.4e-15 at 1/year |
Next: the when guide or vs alternatives. Open the Pulsar Timing Array 3D Explorer.
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