Arjuna realizes that Kiratas are Lord Shiva & Parvathi and prostrates. Shiva and Parvathi blesses Arjuna with Pasupatastra.
This Kirata women is the main deity at Kadampzha and "poo moodal' - covering with flowers- is the main offering. There is a Kirata Shiva temple one mile west. Kirata with bow and arrow is the main deity and both these deities face each other. There is a belief that one has to visit both the temples to please Kadampuzha Devi.
From the book, "Keralathile Kshethrangalilude" published by H & C Publishing, Kunnamkulam.
Information from Krishnakumar Avanoor.