filter_catalog module

This script filters the output catalog based on some conditions

filter_catalog.arcsec2kpc(redshift, theta)

Converts angular size to linear size given a redshift

Parameters
  • redshift (float) – redshift

  • theta (array of floats) – angular size in arcsec

Returns

distance_kpc – linear size in kpc

Return type

array of floats

filter_catalog.compute_d_m(cat)

Computes the Mass of HI and linear diameter of the galaxies in a catalog

Parameters

cat (pandas.DataFrame) – catalog of galaxies

Returns

cat – original catalog adding the columns log(M_HI) and log(D_HI_kpc)

Return type

pandas.DataFrame

filter_catalog.filter_md(df_md, uplim=0.45, downlim=- 0.15)

Removes items from a catalog based on distance from the Wang et al. 2016 2016MNRAS.460.2143W correlation. The values used are log DHI= (0.506±0.003) log MHI−(3.293±0.009)

Parameters
  • df_md (pandas DataFrame) – input catalog in pandas format

  • uplim (float) – Threshold distance to consider outliers in the top region

  • downlim (float) – Threshold distance to consider outliers in the bottom region

Returns

df_out – output catalog without the outliers

Return type

pandas DataFrame

filter_catalog.freq_to_vel(f0_hi=1420405751.786)

Convers line frequency to velocity in km/s

Parameters

f0_hi (float) – rest frequency of the spectral line

Returns

freq2vel – function to convert frequency in Hz to velocity

Return type

function

filter_catalog.get_args()

This function parses and returns arguments passed in

filter_catalog.main()

Gets an input catalog and filters the sources based on deviation from the D_HI M_HI correlation