Passing multiple store-data to Ember Component

I am trying to pass a second model to a component. I have several books that are ordered by categories. The categories are chosen by a Multi-Select-Box and I need to pass the categories (which are stored in my db) to the component. I dont need to change the categories I just need an array. Where and how do I request them and pass them on, if i dont want to inject the store into the component? (There is no way to build a many-to-many relationship, the books only have a string-array for the categories)