I am sorry for your loss.
I am assuming your father was of retirement age or older when he passed. I am also assuming there was no will, and that you were named as a beneficiary recipient on the IRA. If that's the case, and there were "truely" no other assets, there's probably no need to create an estate for the deceased for the purpose of paying taxes and passing on any assets to heirs through probate court. Remember, the designated beneficiary on the IRA account over-rides what any will may say.
However, a final tax return does need to be prepared on behalf of the deceased. If taxes are owed they need to be paid out of that IRA "before" it it passed to you (if possible). If the IRA has already been passed to you and you received documentation to that effect already (such as a 1099-R with your name on it, if you took a distribution) then the taxes should be paid from those IRA proceeds before the beneficiary recipient takes any of it. That's because whatever the beneficiary recipient takes from the IRA after the IRA is passed to them, is taxable income to *that* beneficiary recipient, even if they use it to pay a tax liability of the deceased. There is a work-around for this if this is your case. But you'll need to seek professional help. This would be especially called for if your state also taxes personal income.
