Redox Reactions

Identify oxidant in following reaction.

\(3 \mathrm{H}_3 \mathrm{AsO}_{3(\mathrm{aq})}+\mathrm{BrO}_{3(\mathrm{aq})}^{-} \longrightarrow \mathrm{Br}_{(\mathrm{aq})}^{-}+3 \mathrm{H}_3 \mathrm{AsO}_{4(\mathrm{aq})}\)