。
The train has literally just arrived.
Literal
Train [topic-は] just-now arrived [just-ばかり] [copula-です].
たった今 ('just now, a moment ago') emphasizes the very recent past — more immediate than plain 今. Paired with ついたばかり (the ~たばかり pattern for 'just did'), it pushes the 'just arrived' meaning hard. Note the kana-only つく — the kanji 着く is understood.