Estate Law Questions? Ask an Estate Lawyer.
Hello and welcome! My name is ***** ***** I will try my level best to help with your situation or get you to someone who can.
In AZ, as long as you are over 18 and of sound mind, you can serve as executor (actually Administrator since he had no will) of the estate.
So assuming the above is true, then yes, you can file a probate petition to be appointed Administrator of his estate. You would notify his children (or their guardians if they are minors) of the petition and then they would have an opportunity to object if they wanted to do so. If there were no objections, or none found reasonable by the judge, then you would be appointed by the judge.