Multiband analysis

The multiband analysis in hscPipe can provide the photometry of the objects in every filter. The detected object catalogs created in coaddDriver.py are merged and new catalogs are produced. The hscPipe command multiBandDriver.py is used to perform multiband analysis. If you are interested in the detailed procedure of multiband analysis, please refer to Description of multiBandDriver.py . The PSF-matched photometry is carried out in hscPipe5.

# Directory for reduction is ~/HSC and rerun name test. Filters are g, i2, and r2.
# In case of using local system,
multiBandDriver.py ~/HSC --rerun test --id tract=0 filter=HSC-G^HSC-I2^HSC-R2 --batch-type=smp --cores=8

# multiBandDriver.py [data reduction directory] --rerun [rerun name] --id tract=[tract] filter=[filter1^filter2^...]
# Option
#       --id: Specify all data used in multiband analysis.

For the first step, multiBandDriver.py gathers the positional information of the detected objects in det catalog and creates new merge catalogs (mergeDet). Based on the mergeDet catalogs, the measurements are performed on the coadd images in each filter (meas). In this process, the objects are deblended to child objects when needed. In this measurement, the centroids and object shapes are allow to vary from filter to filter. Then the object information is gathered again and one reference is created (ref). Finally, the measurements are performed again, then forced_src catalogs are created. The generated catalogs are summarized below.

  • List of source positions and footprints containing akk sources detected in any bands: rerun/[rerun]/deepCoadd-results/merged/[tract]/[patch]/mergeDet-[tract]-[patch].fits
  • Source catalog measured on each of sources in a coadd images listed in mergeDet: rerun/[rerun]/deepCoadd-results/[filter]/[tract]/[patch]/meas-[filter]-[tract]-[patch].fits
  • Match list of objects in mergeDet catalogs with reference catalogs: rerun/[rerun]/deepCoadd-results/[filter]/[tract]/[patch]/srcMatch-[filter]-[tract]-[patch].fits
  • List of object measurements and their matched reference catalog information: rerun/[rerun]/deepCoadd-results/[filter]/[tract]/[patch]/srcMatchFull-[filter]-[tract]-[patch].fits
  • List of sources based on meas catalog: rerun/[rerun]/deepCoadd-results/merged/[tract]/[patch]/ref-[tract]-[patch].fits
  • Source catalogs generated by a forced measurement: rerun/[rerun]/deepCoadd-results/[filter]/[tract]/[patch]/forced_src-[filter]-[tract]-[patch].fits

There are schema files in rerun/[rerun]/schema.

Warning

The name of column in these catalogs are different from the ones created hscPipe4.

There are some models of photometry in hscPipe5.

  • Photometry with fixed aperture
    • base_CircularApertureFlux_[3,4,6,9,12,17,25,35,50,70]_[0,5]_flux (fixed radius = [3.0, 4.5, 6.0, 9.0, 12.0, 17.0, 25.0, 35.0, 50.0, 70.0])
  • PSF model (Default PSFEx is used for modeling. Useful for point sources.)
    • base_PsfFlux_flux
  • CModel (Fitted by n = 1 and 4 Sersic profile. Useful for extended objects.)
    • base_CmodelFlux_flux
  • Kron aperture
    • base_KronFlux_flux

The results of PSF-matched photometry is also included in forced catalog. For example,

  • ext_convolved_ConvolvedFlux_seeing: Original seeing
  • ext_convolved_ConvolvedFlux_[0,1,2,3]_kron_flux: Krin flux with matched seeing of [3.5,5.0,6.5,8.0] pixels
  • ext_convolved_ConvolvedFlux_[0,1,2,3]_[3_3,4_5,6_0]_flux: Fixed pixel ([3.3,4.5,6.0] pixcels) apaerture flux with matched seeing of [3.5,5.0,6.5,8.0] pixels

Other parameters can be checked in a schema file (e.g., forced_src schema file).