JuryDutySucks

Hello all I just finished my Biology PhD and am considering applying for another degree program (JD or MBA). I was hoping to rework some of my dissertation work into a publication as well. During my PhD, I had submitted a paper with my PhD advisor to a top tier and second tier biology journal, but my publication was rejected twice. Since then, my paper has languished on my advisor's desk for nearly one year. As one might imagine in a competitive field, this nearly guarantees that a study will be "scooped" (i.e. another group will publish the same or highly similar findings first). My friend, who has a rival paper, is offering me a co-first authorship for providing a single image to his study. He is also willing to offer me co-first authorship for "intellectual contribution." If I do not place my name on his paper, my data will become worthless as my friend will "scoop" us. Moreover, it appears that my friend's study surpassed the study I submitted with my PhD advisor and is being considered for publication in a top-tier journal. I feel the urge to add my name to his paper to get a publication that is related to my dissertation work. The other fact is that I am not on good terms with my PhD advisor (which happens). As a graduate, I am no longer affiliated with the PhD program or institute in which I produced the PhD work. The trouble is, do I need to include my previous advisor as a co-author or I am allowed to add my name to my friend's paper without my PhD advisor's name? Is there a distinction in the rules for providing data or intellectual contribution? So my question is really, is this done? Is it okay to try to publish now that I am temporarily out of academia? Do I need to get in touch with the professors from this past project? Thank you!