Answer:
Radiation.
Step-by-step explanation:
There are three types of heat transfer
Convection : when heat is transfered via fluids its called convection heat transfer.
Radiation : when heat is transfered via electromagnetical waves its called radiation heat transfer.
Conduction: when heat is transfered via solid material its called conduction heat transfer.
Therefore, when heat is transferred from one object to another by electromagnetic rays there is radiation heat transfer