It is said that the gravitational waves (GW), recently detected by LIGO, correspond (according to Einstein General Relativity theory equations) to the effect of two black holes merging (with the masses of both colliding black holes and the mass of the black hole, which resulted due to that merger, being estimated).
Does the above method (detection of gravitational waves) constitute acceptable scientific method of proving with regards that the source of those waves was indeed the merger of two black holes (as definitely existing astronomical objects), or is it still at best currently possible implied assumption?
Since in the given case, existence of black holes is derived using two steps of inference from the General Relativity Theory mathematical model, should there be at least two independent of each other methods to claim the discovery of those two black holes as astronomical objects?
As an alternative, could LIGO signature detected GW possibly have been produced by collision/merge/annihilation of some matter and antimatter objects (this one is highly hypothetical assumptive question and I am asking it just to illustrate my point that the collision of two BHs, implied as the cause of LIGO detected GW, perhaps should be considered as just highly probable but not absolutely established astronomical fact)?
Could this issue (specifically with regards to detection of two black holes merge and existence of resulted from that merge single black hole) be compared (in the sense that both relied on indirect evidence analogy) with the issue of existence of Planet 9 (per California Institute of Technology astronomers Konstantin Batygin, a theoretician, and Mike Brown), which is considered at this point as just a hypothesis (with all evidence of its existence being indirect and relying on the calculational model)?
P.S. It is interesting (see below link)
that at the beginning of above article the word "discovery" was only applied by Stephen Hawking to the detection of gravitational waves as such, but further the term "discovery" was extended as:
"This discovery is the first detection of a black hole binary system and the first observation of black holes merging.”
"Asked what more could be discovered if scientists scanned for gravitational waves, he said: “Apart from testing general relativity, we could hope to see black holes throughout the history of the universe. We may even see relics of the very early universe during the big bang at the most extreme energies possible.”"
This question is a refinement of the previously asked by me question
which was diluted (Mia culpa) by another issue (related to classification of black holes).
I would like to see here an answer, which would more in general cover the subject of methodologies, with regards what constitutes discovery in PHYSICS (such as the phenomena of gravitational waves) versus discovery in ASTRONOMY (such as discovery of black holes, as astronomical objects). With regards to LIGO detection, I think that it amounts to discovery (in the field of Physics) of gravitational waves (as physical phenomena), but I do question whether LIGO detection constitutes a discovery (in the field of Astronomy) of specific black holes (as astronomical objects) - the latter one, IMHO, should be characterized as highly plausible very probable hypothesis ...
Could someone offer me the historical ASTRONOMY precedent when the second degree of inference (from the mathematical model, being associated with the theory of Physics) was accepted as the discovery of the astronomical object?