ex dies owing child support 47,000 inchild support arrears. No will

First of all, let me say that I feel for you and your situation.  I don't have any easy answers for you.  I'll first tell you that unpaid child support can be filed as a judgment against your ex.  That might make a difference if he had assets that can be attached.  The first question I have is whether an estate has been opened following his death.  You can check your local Register of Wills office to see if that's happened.  If it hasn't happened, you can actually file papers with the Register seeking to open his estate and to be appointed as the personal representative of the Estate (an Administrator).  If that happens, then you are in control of "marshalling" his assets.  That means you can find his assets, take possession of them and administer them to pay his debts (your judgment being at the front of the line) and distribute the balance according to the state intestacy laws (likely to his children).  This would help only with assets that are in his name alone.  If he had joint bank accounts, qualified retirement accounts (e.g. IRA, etc.) or any other account that has a "pay on death" designation, you may not be able to get to those assets.  Its complicated.  You really need to sit down with an attorney experienced in administering estates and collecting judgments for a more in-depth consultation.  All the best -- Mike