Namaste,
Arya means noble, cultured, ethical and civilized in Veda and Sanskrit, not referring to any particular group or people or tribe at all. Aryan is a European corruption of the word Arya. Now when the Europeans came they assumed Arya means a race of people who are noble, cultured ect ect. at first they assumed that the Europeans came from India and Indian Aryans were their ancestors, then slowly their romance with India faded and as the 17th and 18th Centuries Europe were popular for its racism and race sciences, they assumed that such a Aryan race must be white or European because the inferior "N i g g e r s of India", cannot be capable of producing such great Sanskrit works nor would they be capable of influencing and producing the civilizations that flourished in most of Asia.
The famous Max Muller (Orientalist) notes the mood of the Europeans especially the British of the day, here is a quote from Max.
They would not have it [referring to the British], they would not believe that there could be any community of origin between the people of Athens and Rome, and the so-called N i g g e r s of India. The classical scholars scouted the idea, and I still remember the time, when I was a student at Leipzig and begun to study Sanskrit, with what contempt any remarks on Sanskrit or comparative grammar were treated by my teachers . . . No one ever was for a time so completely laughed down as Professor Bopp, when he first published his Comparative Grammar of Sanskrit, Zend, Greek, Latin and Gothic. All hands were against him.
(1883: 28)
Edward F Bryant in the book: (i suggest you get a copy)
THE INDO-ARYAN CONTROVERSY Evidence and inference in Indian history: in his concluding remarks makes this observation about the situation at the time the "Love", for Indian things ended. He writes:
"India was considered the cradle of civilization as the homeland of the Aryans, but, by the century’s end, it was viewed by some as its grave."
In the same book there are plenty of discussions from both sides of the debate, but as there is no conclusive answer to this "Aryan Myth", and i think that is purely because there never was a Aryan group of speakers nor was there are Aryan race in the first place, i think this is just 200 years of discussion and debate on something that probably is imaginations of the early orientalists.
Anyways this is what i gather from my limited readings of many books.