Which transactions are deadlocked?

Our database is running into problems, as many transactions are waiting for locks held by other transactions. Here is what each transaction is waiting for:

T1 is waiting on T4

T5 is waiting on T8

T2 is waiting on T7

T6 is waiting on T2

T3 is waiting on T2

T7 is waiting on T6

T4 is waiting on T1

T8 is not waiting

Which transactions are deadlocked?