Abstract was selected for 'oral abstracts' competition, in a shortlist of 5 presenters. I was announced winner at the end of the competition. Following the event I have been emailed to pass on my bank details as the beneficiary of the £1500 prize. My co-authors are all seniors/co-supervisors. What should I do? Should I email them all to discuss splitting up the share? Or should I not raise the matter at all, to avoid embarrassment. From reading responses to a similar post before, I get the impression that since the award is for best Oral Presentation, and I am the only 'student' it should probably just go to me. At the same time, I don't want to just keep it without mentioning it to anybody.
You should absolutely inform your co-authors
These people care about your career. They will be your recommenders, they will help you find jobs. People will ask them about your work. "Hey, I just won a big prize" is something I'd want to know if it was one of my students or postdocs - because I'd proceed to cheerfully show off the awesome work people in my lab are doing.
You can broach the subject of splitting the prize with them, but personally you did the presentation, and you won the award. If I was on the paper, I'd settle for a warm fuzzy feeling.
Congratulations! It will not hurt to let your co-authors know about the prize, and you can certainly offer to share the amount as well. As a student and presumably the only presenter, you are the primary recipient of this award, but your supervisors will likely be glad to know you received a substantial award.