The phrase "a topic of vigorous" is not complete and lacks context, but it is grammatically correct and can be used in written English.
You can use it when discussing a subject that is being actively debated or discussed with enthusiasm and energy.
Example: "The conference focused on a topic of vigorous debate among scientists regarding climate change."
Alternatives: "a subject of intense" or "an issue of lively".
It turned Potash, to the surprise of many Canadians, into a topic of vigorous political debate.
Why do you think race and TV casting is a topic of vigorous discussion right now in our culture?
Foremost among them is the definition of "patentable subject matter," in other words, reaching universal agreement on what may be patented, a topic of vigorous debate.
The conversion of marginal lands into monoculture production areas for biomass crops is a topic of vigorous debate with various unresolved issues, notably the relative carbon sequestration benefits and productivity of monocultures vs. polycultures [5], the disruption of ecosystem services provided by marginal lands [6], [7], and the invasiveness risks of the species being considered [8], [9].
The cascading reactions underlying transduction of the PINK1 and Parkin 'mitochondrial damage' signal remain a topic of vigorous research.
It should be noted, however, that these associations remain a topic of vigorous investigation and debate (Hodges et al. 2004; Mesulam et al. 2008).
The value of corporate philanthropy is a topic of ongoing and vigorous discussion.
Now, these topics are a matter of vigorous public debate.
The bird's ecology and conservation are the topic of vigorous debate among foresters, wildlife ecologists, academics, politicians, social scientists, and economists (e.g., Dixon and Juelson 1987, Simberloff 1987, McKillop 1992, Sample and Le Master 1992, Thomas and Verner 1992, Meslow 1993, Yaffee 1994).
The point at which this happens is nebulous, as is evident from the fact that it's still the topic of vigorous professional discussion.
