Magento: "core.13528" files?

Some files showed up mysteriously in my Magento shop home f开发者_C百科older, they're all named core.13528, core.13529...there's about 40 of them, and all take up to 400MB!!

Does anyone know what do they mean and how did they got there? Can I delete them?

These are core dumps - memory images from failed processes. You don't need them unless you are in a position to analyze program crashes with a debugger (or if you submit bug reports to the authors who are).

However, if the numbers (usually process IDs) are consecutive, it looks like your processes always crash eventually - this should be a cause of worry.