diff options
Diffstat (limited to 'bin/cosmo_calc.py')
| -rwxr-xr-x | bin/cosmo_calc.py | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/bin/cosmo_calc.py b/bin/cosmo_calc.py index 1302bdb..3f0b81f 100755 --- a/bin/cosmo_calc.py +++ b/bin/cosmo_calc.py @@ -74,15 +74,22 @@ def calc_quantity(q, calculator, args): def main(): + # Hubble parameter at present day + H0 = 71.0 # [km/s/Mpc] + # Present-day matter density + Om0 = 0.27 + # Chandra ACIS pixel size + pixelsize = 0.492 # [arcsec] + parser = argparse.ArgumentParser( description="Cosmology calculator with Chandra-specific quantities") parser.add_argument("-H", "--hubble", dest="H0", - type=float, default=71.0, + type=float, default=H0, help="Present-day Hubble parameter " + - "(default: 71 km/s/Mpc)") + "(default: %s [km/s/Mpc])" % H0) parser.add_argument("-M", "--omega-m", dest="Om0", - type=float, default=0.27, - help="Present-day matter density (default: 0.27") + type=float, default=Om0, + help="Present-day matter density (default: %s)" % Om0) parser.add_argument("-b", "--brief", dest="brief", action="store_true", help="be brief") parser.add_argument("-U", "--unit", dest="unit", @@ -102,11 +109,11 @@ def main(): parser.add_argument("--kpc-per-pix", dest="kpc_per_pix", action="store_true", help="calculate the transversal length [kpc] " + - "w.r.t. 1 ACIS pixel (0.492 arcsec) at DA(z)") + "w.r.t. 1 pixel (%s [arcsec]) at DA(z)" % pixelsize) parser.add_argument("--cm-per-pix", dest="cm_per_pix", action="store_true", help="calculate the transversal length [cm] " + - "w.r.t. 1 ACIS pixel (0.492 arcsec) at DA(z)") + "w.r.t. 1 pixel (%s [arcsec]) at DA(z)" % pixelsize) parser.add_argument("--norm-apec", dest="norm_apec", action="store_true", help="calculate the normalization factor " + |