Yes.
If so, what are they? Are these only notarial acts or also acts of other authorities?
Article 224 of the Contentious Civil Procedure Act gives the definition of an authentic instrument (see answer to question 2.). Under Notaries Act, notarial instruments are notarial deeds, notarial minutes and notarial certificates. Notarial instruments are considered authentic instruments, provided that all the essential formalities required by this Act have been observed in their drafting.
Certain other documents could fall within the scope of the definition as well, when prescribed so by the law – e.g. The General Administrative Procedure Act , Art. 169.