I understand that I can use EM in a JEE 1.4 environment by handling the EM myself. So am I correct in understanding that this then is an Application-managed entity manger?

I want to make use of Container Managed Transactions as provided by my application server. So is this possible with an application managed EM?
(On page 2 of the Hibernate EM document it says that an application managed entity manger can be involved in the current JTA transaction.)

I have the following configuration:
<persistence-unit name="persistence" transaction-type="JTA">
<jta-data-source>java:comp/env/Hiber DataSource</jta-data-source>
<property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.WebSphereExtendedJTATransactionLookup"/>

So if the above is possible, does it mean that the persistence context is associated with the JTA transaction lifecycle as stated in the document?
So when the EM is invoked the persistence context is opened if not already associated with the current JTA tx and the persistence context ends when the JTA tx completes?
OR do you have to propagate the persistence context yourself?

yes, this is considered an application managed EM
If the em is created when a JTA transaction is already active, then the EM joins the transaction
Otherwise, when the transaction is active you need to call em.joinTransaction()

you still have to close() the EM