In the course of my PhD I have written a few papers that I am planning on incorporating into my dissertation. I was first author on these papers and legitimately wrote and developed the high majority of the papers (as in, I wasn't just gifted "first author" status). In the course of our papers, my co-authors and I used some computer simulations to verify our theoretical results.
While I developed all of the theory for the paper independently, another graduate student did some of the grunt work writing the code for one of the simulations. This was done mainly just to expedite the submission of our paper, and not because I had no idea what was going on with the simulations. I actually helped develop the intricacies of the simulation; it just was not my hands on the keyboard coding it. Can I just cite our own paper in my dissertation and use its results as if they are my own, or do I need to independently replicate the results that my fellow grad student found in order to use them in my dissertation?
The underlying question here comes down to how much I can "self-cite" as my own a part of a paper that I was the main author for, but did not explicitly produce? I am aware that citing a paper I wrote is fine. I am even okay copying wording directly for certain potions of the dissertation (with a note explaining the replication). However it is unclear if I can use results that someone else found as part of my dissertation. His results give application for the theoretical framework that I am establishing for my dissertation.