Simplify the following text for a Grade 4 native English-speaking person.
Original: The yellow arrows also form a cross , which symbolizes both the Southern Cross , a constellation seen only in the Southern Hemisphere and the Roman Catholic or Christian symbol of redemption brought by Pedro Ã lvares Cabral and under whose shadow the first Mass in Brazil was celebrated in 1500 in Bahia .
Simplified: The yellow arrows also form a cross . This is a symbol of the Southern Cross carried by Pedro Ã lvares Cabral .