# FAQ

## Should I contact a Caterpillar core member to use the data?

For using the merger tree and halo catalogs, no, you now no longer need to contact a core member. That being said however, we do encourage you to contact a core member as certain efforts may have been undertaken by groups either internally and externally and we can put you in direct contact with them to coordinate efforts.

## Why aren't the particle snapshots public?

This is primarily because unlink many other simulation suites, the particle resolution and snapshot resolution make it expensive to 100% host on public servers (e.g. Google Cloud Platform). Should you want more than the z = 0 snapshot, please get in touch so we can find the best path forward for your project.


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