ALMA has begun work on correcting some Cycle 7 interferometric datasets for a visibility amplitude calibration error that affects fields containing strong astronomical emission -details were described in this previous announcement. For all affected datasets with a >10% flux scale offset that have yet to be delivered, including those that will be observed in the remainder of Cycle 7 and in Cycle 8 2021, ALMA will apply a renormalization correction during data processing to correctly scale the amplitude calibration before being sent to PIs. For affected datasets with flux scale offsets >2% but <10%, ALMA will provide renormalized data on request from the PI as needed. For affected data in the ALMA Archive, an investigation is underway and plans will be described in a future announcement.
Update on the Amplitude Calibration Issue Affecting some ALMA Data
Published: 24 Aug 2021