Star quantities for Roman-Rubin sims

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 UW star catalog) and a flux file. The latter contains for each object only fluxes for lsst bands and the object id so it can be joined with the main file. Both are parquet files.

Star main file

Note the same schema may be used for SNe. Some fields are unused for stars.

Name	Datatype	Units	Description
object_type	string	N/A	In practice always ‘star’
id	string	N/A	Unique object identifier
ra	double	degrees	Object right ascension
dec	double	degrees	Object declination
host_galaxy_id	int64	N/A	Unused for stars
magnorm	double	N/A	To be applied to SED
sed_filepath	string	N/A	Path to object’s SED file relative to env variable SIMS_SED_LIBRARY_DIR
MW_rv	float	N/A	Extinction parameter
MW_av	float	N/A	Extinction parameter from F19 dust map
mura	double	milarcsec per year	RA proper motion
mudec	double	milarcsec per year	Declin. proper motion
radial_velocity	double	km/sec	Radial velocity
parallax	double	milarcsec	Parallax
variability_model	string	N/A	Unused for stars
salt2_params	struct	N/A	Unused for stars

Star flux file

Name	Datatype	Units	Description
id	string	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