The phrase "alien subject" is correct and usable in written English.
It can be used in contexts discussing topics or themes that are foreign or unfamiliar to a particular audience or field of study.
Example: "The researchers found that the alien subject of their study posed unique challenges in understanding its implications."
Alternatives: "foreign topic" or "unfamiliar theme".
He was abruptly locked up in November as a "criminal alien," subject to mandatory deportation to China -- the nation he left at 5, when his family immigrated legally to the United States.
"Mazen Al-Najjar is an alien subject to a final deportation order who has been illegally present in the United States for many years," Ms. Reno said in a statement.
Because the man, Ralph Richardson, had a previous conviction for cocaine trafficking, immigration officials treated him not as a returning lawful resident, but as an "arriving alien," subject to incarceration and automatic "removal" proceedings under the 1996 immigration law.
According to The Times of London, his affection for his adopted country was evident in a story he told about how, after the outbreak of World War II, the police informed him that on his 16th birthday he would become an enemy alien subject to internment.
Self-directable acts are such that the subject toward whom they are directed may be identical with the subject of the act (as in cases of self-pity, self-hatred, etc).. Non-self-directable acts, on the other hand, such as forgiving or praying, demand an alien subject.
… Art should not be an alien subject simply because schools have less resources.
In early 1996, Congress explicitly expanded the group of aliens subject to mandatory detention, eliminating provisions that permitted release of criminal aliens who had at one time been lawfully admitted to the United States.
Congress' decision to ameliorate the condition of aliens subject to a final order of removal who cannot be repatriated, but who need not be detained, illustrates a balance in the statutory design.
No one prepared me for the loss of control: a woman who had spent her professional life as a senior lawyer managing and giving instructions, now I was subject to alien discipline.
Assume that however alien your subject's life has been compared with yours, the same basic preoccupations will have underpinned it: love, money, death and ambition.
Later, the actor threatened the government and individual agents in his pursuit, declaring himself a "nonresident alien" not subject to tax laws.
