My father passed away last month and I was wondering what do I do about his pension?

I don't know where it comes from. Do I need to notify them that he has passed?

does social security inform them?

Do I still have to file a tax returm for him?

Additionally, is his ex-wife entitled to it now that he has passed?

My father wasn't much on planning so I have to straighten all this out now.

Thanks

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