Prev: P13.5 Next: P13.7

P13.6: Gwyn, Stephen
Stephen Gwyn (Canadian Astronomy Data Centre)







Theme: Other
Title: MegaPipe 2.0: 10000 square degrees of CFHT MegaCam imaging

MegaPipe, the MegaCam data processing pipeline at the CADC, has been upgraded to version 2.0 and has processed 10000 square degrees of the sky. MegaPipe has been operating since 2008. It was originally intended to increase the usage of archival MegaCam data by calibrating and stacking the images as they became public. That focus moved to include processing data from the CFHT Large Programs such as the NGVS, OSSOS, VESTIGE and CFIS. MegaPipe 2.0 represents several improvements. The advent of GAIA means that the astrometric calibration is considerably more accurate. The public release of Pan-STARRS allows photometric calibration of images that even if they were taken under non-photometric conditions, by using the PS1 stars as in-field standards. Together this means that almost every MegaCam image can be astrometrically/photometrically calibrated to sufficient accuracy to allow stacking (30 mas and 0.01 magnitudes respectively). The other change going to MegaPipe 2.0 is how the images are stacked. Previously, MegaPipe only stacked images that were taken on more or less the same part of the sky. This limited the number of images that could stacked. MegaPipe 2.0 instead stacks on set of 10000x10000 pixel tiles, each half a degree square evenly covering the whole sky. The result that twice much sky area can stacked. There are now 10000 square degrees of imaging in the ugriz bands available for download at: http://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/en/megapipe/access/graph.html

Link to PDF (may not be available yet): P13-6.pdf