Who are the noble ones and who are their disciples?

In the suttas, we read about the noble ones (*ariya*) and the disciples of the noble ones (*ariyasavaka*). Who are the noble ones? Do they include only the four persons who are the stream enterers, once-returners, never-returners and arahants? Or do they also include the four persons trying to achieve stream entry, once-returnership, never-returnership and arahantship? Together, the eight form the noble sangha. Who are the disciples of the noble ones? Do they include the four persons trying to achieve stream entry, once-returnership, never-returnership and arahantship? Is there any overlap between the two? References from the Pali Canon on this is appreciated.