++++++++++++++++++++++++++++++++++++++++++++++++++ Galaxy quantities for Roman-Rubin joint simulation ++++++++++++++++++++++++++++++++++++++++++++++++++ Data are partitioned by (nside=32, ring ordering) healpixel. For each pixel there is a so-called "main file" (with information largely coming from the diffsky galaxy catalog), a flux file and a SED file. The flux file contains for each object only fluxes for lsst and Roman bands and the object id so it can be joined with the main file. Both it and the main file are parquet files. The SED file is in hdf5 format. The file names take the form galaxy_.parquet (main file), galaxy_flux_.parquet (flux file) and galaxy_sed_.hdf5 for SED files. In all cases is the id of the healpixel covered by the file. Galaxy main file ---------------- ============================= ======== ========== ========================== Name Datatype Units Description ============================= ======== ========== ========================== galaxy_id int64 N/A Unique object identifier ra double degrees Object right ascension dec double degrees Object declination redshift double N/A Cosmological redshift with line-of-sight motion redshiftHubble double N/A Cosmological redshift peculiarVelocity double km/sec Peculiar velocity shear1 double N/A Shear (gamma) component 1, treecorr/Galsim convention shear2 double N/A Shear (gamma) component 2, treecorr/Galsim convention convergence double N/A Convergence (kappa) spheroidHalfLightRadiusArcsec float arcsec Bulge component half-light radius diskHalfLightRadiusArcsec float arcsec Disk component half-light radius diskEllipticity1 double N/A Ellipticity component 1 for disk, not lensed diskEllipticity2 double N/A Ellipticity component 2 for disk, not lensed spheroidEllipticity1 double N/A Ellipticity component 1 for bulge, not lensed spheroidEllipticity2 double N/A Ellipticity component 2 for bulge, not lensed um_source_galaxy_obs_sm float solar mass Stellar mass (h=0.7) MW_rv float N/A Extinction parameter MW_av float N/A Extinction parameter from F19 dust map ============================= ======== ========== ========================== Galaxy flux file ---------------- =============== ======== ================ ==================================== Name Datatype Units Description =============== ======== ================ ==================================== galaxy_id int64 N/A Unique object identifier lsst_flux_u float photons/sec/cm^2 Flux integrated over lsst u-band lsst_flux_g float photons/sec/cm^2 Flux integrated over lsst g-band lsst_flux_r float photons/sec/cm^2 Flux integrated over lsst r-band lsst_flux_i float photons/sec/cm^2 Flux integrated over lsst i-band lsst_flux_z float photons/sec/cm^2 Flux integrated over lsst z-band lsst_flux_y float photons/sec/cm^2 Flux integrated over lsst y-band roman_flux_W146 float photons/sec/cm^2 Flux integrated over roman W146-band roman_flux_R062 float photons/sec/cm^2 Flux integrated over roman R062-band roman_flux_Z087 float photons/sec/cm^2 Flux integrated over roman Z087-band roman_flux_Y106 float photons/sec/cm^2 Flux integrated over roman Y106-band roman_flux_J129 float photons/sec/cm^2 Flux integrated over roman J129-band roman_flux_H158 float photons/sec/cm^2 Flux integrated over roman H158-band roman_flux_F184 float photons/sec/cm^2 Flux integrated over roman F184-band roman_flux_K213 float photons/sec/cm^2 Flux integrated over roman K213-band =============== ======== ================ ==================================== Galaxy SED file --------------- This file has two sections. One (**meta**) has an array **wave_list**, shape(312), of wavelengths (angstroms), which is used for SEDs of all galaxies in the file's healpixel. The other section, **galaxy**, contains groups of galaxies. Each group has entries for individual galaxies, keyed by galaxy id. Such an entry is an array, shape(3, 312), consisting of SEDs for the three galaxy components (disk, bulge, knot). Units are fnu.