Android : What is the meaning of hexadecimal number that see in strings of MAT report?

I used eclipse Memory Analysis Tool ( MAT ) to take a heap dump profile for a process on an android device. along with all objects I see a cryptic looking hexadecimal number

example:

android.graphics.Bitmap @ 0x428e5c90

android.graphics.Bitmap @ 0x428f5888

android.graphics.Bitmap @ 0x42717950

android.graphics.Bitmap @ 0x426fed10

Can anyone help me find out what these numbers are and also can i use them in tracking more specifically the items they are associated to?