One-to-one ARs and an identity crisis

I'm going to be honest, I have a couple of hunches about what my
issue(s) may be, but need some help.
I have Course, SlideShow, TestMaster, and Session entities. I *thought*
that Course, SlideShow, and Session were their own ARs, and TestMaster
was part of SlideShow. Here's why:
A Course is a simple container with a CourseId that has a description
and "Offerings". Offerings is a simple value object. It answers the
questions "is the course available online" and "is the course available
in the classroom". That's it.
However, a SlideShow *only* exists if the course is available online
(more accurately it is only "enabled" if offered online). A SlideShow is
a one-to-one with the course. Currently I create the SlideShow when the
event "CourseOfferingsChanged" is triggered and add it to the repository
(persistence uses transactions and UoW). Also, I'm not sure what the
identity of a slide show is. I have been using the Course ID--this is
how I currently look up the SlideShow from the repository.
How can SlideShow be its own AR? I am updating 2 ARs (read: what I
thought/think were/are 2 ARs) in a single transaction, and SlideShow
*only* exists when the Course exists AND Offerings contains the option
"is online".
Also note that in-classroom sessions are accessed via the repository and
created via client code using simple class construction (e.g. new
Session($courseId, $date, $duration, $signupClosesOn, etc...)).
Q. Am I correct in thinking that SlideShow as its own AR is a smell?
Q. How does one reconcile this relationship?