Since your audience for this essay is the group of authors you used to inquire into your issue in the first place, it'll be easy to use skills you already know in order to profile them. Start by looking at the language used by those authors. Using your own analytical skills, what does the language your audience uses tell you about them? What do they value? What kinds of language do they respond to best? Write down what you think are the primary characteristics of your audience based on their language, listing examples from their writing to support each of your ideas. Spend at least a page on this--you'll be glad you did later.