Tools for making DEIMOS slit masks

pip install masktools==0.0.6



Utilities for designing DEIMOS slitmasks



Required packages

  • numpy (tested on 1.11.0)
  • astropy (tested on 1.1.1)
  • matplotlib (tested on 1.5.0)
  • astroquery (tested on 0.3.1)


This package is for creating distributions of SKiMS (Stellar Kinematics with Multiple Slits) which optimally sample the integrated stellar light of a galaxy.

Authors: Nicola Pastorello and Asher Wasserman

This packages installs the superskims script, which creates dsim input files for a given galaxy.

usage: superskims [-h] [-m MU_EFF] [-r RA] [-d DEC] [-q] name R_eff axial_ratio position_angle num_masks

This script generates dsim input files from the inputted galaxy parameters

positional arguments: name Name of galaxy for output and NED lookup R_eff Effective radius of galaxy in arcseconds axial_ratio Ratio of minor axis to major axis position_angle In degrees counter-clockwise from North num_masks Number of masks for the galaxy

optional arguments: -h, --help show this help message and exit -m MU_EFF, --mu_eff MU_EFF Effective surface brightness in mag/arcsec^2, default is 22 -r RA, --ra RA Right ascension, in degrees J2000. If name is findable by NED, will use that one instead. -d DEC, --dec DEC Declination, in degrees J2000. If name is findable by NED, will use that one instead. -q, --quiet If toggled, suppress console output.

For more fine-grained control, you can access the Mask and Galaxy classes through the masktools.superskims package while within a python environment, e.g.,::

from masktools import superskims
from astropy.coordinates import SkyCoord
center = SkyCoord('12h35m37.9s +12d15m50s')
galaxy = superskims.Galaxy(name='N4551', center=center, r_eff=16.6, 
                           axial_ratio=0.75, position_angle=70.5)
for mask in galaxy.masks:
    output_file = + '_PA{:0.1f}_superskims.dsim'.format(mask.mask_pa)
    superskims.outputs.save_to_dsim(mask,, output_file)


This package is for obtaining good guide stars and align stars for a mask. Work in progress. The get_table method in the query_usno model is likely to be reorganized at some point.