It's hard to determine why "on the right" might be used in this citing (with angels possibly not lacking "authority or honour”). At the same time Jesus probably didn't need more honor while in heaven; he sat on the right hand of God.
Mark 16:19 (KJV)
So then after the Lord had spoken unto them, he was received up into heaven, and sat on the right hand of God.
Of the several ways in the “biblical usages of ‘right’ and ‘left’ ”, one was just that the right side was traditionally considered better than the left, all the way back to Genesis, because the right was the “side of honor” and “recognized in many ways to be the better”. The right side of a person received “special prominence”. Actually, being left-handed was even considered a disqualification for priesthood.
http://www.jewishencyclopedia.com/articles/12757-right-and-left
Right was also considered the "stronger" side. http://www.jewishvirtuallibrary.org/jsource/judaica/ejud_0002_0017_0_16755.html
In one case in Genesis when blessings took place, Isaac was blessing two grandsons he had next to him, but he even crossed his hands since he knew the younger would surpass the older.
Gen 48:13-16
13 And Joseph took them both, Ephraim in his right hand toward Israel's left hand, and Manasseh in his left hand toward Israel's right hand, and brought them near unto him.14 And Israel stretched out his right hand, and laid it upon Ephraim's head, who was the younger, and his left hand upon Manasseh's head, guiding his hands wittingly; for Manasseh was the firstborn. 17 And when Joseph saw that his father laid his right hand upon the head of Ephraim, it displeased him: and he held up his father's hand, to remove it from Ephraim's head unto Manasseh's head. 18 And Joseph said unto his father, Not so, my father: for this is the firstborn; put thy right hand upon his head. 19 And his father refused, and said, I know it, my son, I know it: he also shall become a people, and he also shall be great: but truly his younger brother shall be greater than he, and his seed shall become a multitude of nations.
In summary there may not be clearer reasons for emphasizing the right side, especially with the angels, then Jesus in heaven.
δεξιός
, an adjective and also means metaphorically a place of honour or authority.