The phrase "a subject of deep" is correct and usable in written English.
It can be used when discussing a topic that evokes strong emotions or requires thorough exploration.
Example: "The book delves into a subject of deep philosophical significance that challenges our understanding of existence."
Alternatives: "a matter of profound" or "a topic of great".
In this new book, she has taken on a subject of deep moral consequence.
But it is a subject of deep and increasingly urgent importance for us in this country.
Among Texans, queso is a subject of deep passion and pride.
The Times refused, saying it had "published newsworthy information about a subject of deep public concern".
In most schools and families it remains a subject of deep shadow and denial, students, parents and health professionals say.
The credibility of Bush administration claims linking Iraq to Al Qaeda and other terrorist groups was, at the time, a subject of deep controversy.
The economic recovery bill is a subject of deep-rooted policy and ideological differences between the parties, with Republicans favoring a top-down approach and Democrats proposing a bottom-up strategy.
The behaviour of civil engineering works (structures, buildings, dams, etc). in time is a current problem which is the subject of deep consideration and numerous research projects.
That's the way regulation goes and if Goldman is surprised by all this, it's yet more evidence that the firm doesn't fully fathom its power as a symbol of Wall Street practices that are now the subject of deep democratic revulsion.
As the risks of long-term damage from concussions have become more evident, head impacts in football and other sports have become the subject of deep concern, much study and even Congressional hearings in recent years.
Last month, a wealthy resident stepped in to help the Casparados secure the former grammar school, built in 1912, as a community center, where even the symbols on the flagpole -- the American flag, the state flag and the Earth Flag, in that order -- were the subject of deep philosophical debate.
