code: def filter_catalog(catalog, **kwargs):
      bright_limit = kwargs.get('bright_limit', 1.00)
      max_bright = kwargs.get('max_bright', None)
      min_bright = kwargs.get('min_bright', 20)
      colname = kwargs.get('colname', 'vegamag')
      phot_column = catalog[colname]
      num_sources = len(phot_column)
      sort_indx = np.argsort(phot_column)
      if max_bright is None:
          max_bright = num_sources
      limit_num = max(int(num_sources * bright_limit), min_bright)
      limit_num = min(max_bright, limit_num, num_sources)
      new_catalog = catalog[sort_indx[:limit_num]]
      return new_catalog