SA13 master catalogue

Checks and diagnostics

There is very little data on SA13 so there is very little data to compare to.

In [1]:
from herschelhelp_internal import git_version
print("This notebook was run with herschelhelp_internal version: \n{}".format(git_version()))
This notebook was run with herschelhelp_internal version: 
255270d (Fri Nov 24 10:35:51 2017 +0000)
In [2]:
%matplotlib inline
#%config InlineBackend.figure_format = 'svg'

import matplotlib.pyplot as plt
plt.rc('figure', figsize=(10, 6))
plt.style.use('ggplot')

import locale
locale.setlocale(locale.LC_ALL, 'en_GB')

import os
import time
import itertools

from astropy.coordinates import SkyCoord
from astropy.table import Table
from astropy import units as u
from astropy import visualization as vis
import numpy as np
from matplotlib_venn import venn3, venn2

from herschelhelp_internal.masterlist import (nb_compare_mags, nb_ccplots, nb_histograms, find_last_ml_suffix,
                                              quick_checks)
In [3]:
OUT_DIR = os.environ.get('OUT_DIR', "./data")
SUFFIX = find_last_ml_suffix()
#SUFFIX = "20171016"

master_catalogue_filename = "master_catalogue_sa13_{}.fits".format(SUFFIX)
master_catalogue = Table.read("{}/{}".format(OUT_DIR, master_catalogue_filename))

print("Diagnostics done using: {}".format(master_catalogue_filename))
Diagnostics done using: master_catalogue_sa13_20171123.fits

0 - Quick checks

In [4]:
quick_checks(master_catalogue)
The column merr_ap_bass_g contains 479 zero or negative values!it's minimum is -601.4183959960938.
The column f_bass_g contains 681 zero or negative values!it's minimum is -155.7931671142578.
The column merr_bass_g contains 384 zero or negative values!it's minimum is -264.1638488769531.
The column merr_ap_bass_r contains 249 zero or negative values!it's minimum is -91.37073516845703.
The column f_bass_r contains 161 zero or negative values!it's minimum is -195.38099670410156.
The column merr_bass_r contains 160 zero or negative values!it's minimum is -13190.6357421875.
The column merr_ap_bass_z contains 249 zero or negative values!it's minimum is -550.5607299804688.
The column f_bass_z contains 331 zero or negative values!it's minimum is -171.47164916992188.
The column merr_bass_z contains 150 zero or negative values!it's minimum is -162.03775024414062.

I - Summary of wavelength domains

In [5]:
flag_obs = master_catalogue['flag_optnir_obs']
flag_det = master_catalogue['flag_optnir_det']
In [6]:
venn2(
    [
        np.sum(flag_obs == 1),
        np.sum(flag_obs == 2),
        np.sum(flag_obs == 3)
    ],
    set_labels=('Optical', 'near-IR'),
    subset_label_formatter=lambda x: "{}%".format(int(100*x/len(flag_obs)))
)
plt.title("Wavelength domain observations");
In [7]:
venn2(
    [
        np.sum(flag_det[flag_obs == 3] == 1),
        np.sum(flag_det[flag_obs == 3] == 2),
        np.sum(flag_det[flag_obs == 3] == 3)
    ],
    set_labels=( 'Optical', 'near-IR'),
    subset_label_formatter=lambda x: "{}%".format(int(100*x/np.sum(flag_det != 0)))
)
plt.title("Detection of the {} sources detected\n in any wavelength domains "
          "(among {} sources)".format(
              locale.format('%d', np.sum(flag_det != 0), grouping=True),
              locale.format('%d', len(flag_det), grouping=True)));

II - Comparing magnitudes in similar filters

The master list if composed of several catalogues containing magnitudes in similar filters on different instruments. We are comparing the magnitudes in these corresponding filters.

In [8]:
u_bands = []
g_bands = ["BASS g"]
r_bands = ["BASS r"]
i_bands = []
z_bands = ["BASS z"]
y_bands = []

II.a - Comparing depths

We compare the histograms of the total aperture magnitudes of similar bands.

In [9]:
for bands in [g_bands + r_bands + z_bands]:
    colnames = ["m_{}".format(band.replace(" ", "_").lower()) for band in bands]
    nb_histograms(master_catalogue, colnames, bands)

II.b - Comparing magnitudes

We compare one to one each magnitude in similar bands.

In [10]:
# There are no comparable bands.

# for band_of_a_kind in [u_bands, g_bands, r_bands, i_bands, z_bands, y_bands]:
#     for band1, band2 in itertools.combinations(band_of_a_kind, 2):
#         
#         basecol1, basecol2 = band1.replace(" ", "_").lower(), band2.replace(" ", "_").lower()
#         
#         col1, col2 = "m_ap_{}".format(basecol1), "m_ap_{}".format(basecol2)
#         nb_compare_mags(master_catalogue[col1], master_catalogue[col2], 
#                         labels=("{} (aperture)".format(band1), "{} (aperture)".format(band2)))
#         
#         col1, col2 = "m_{}".format(basecol1), "m_{}".format(basecol2)
#         nb_compare_mags(master_catalogue[col1], master_catalogue[col2], 
#                         labels=("{} (total)".format(band1), "{} (total)".format(band2)))

III - Comparing magnitudes to reference bands

Cross-match the master list to 2MASS to compare magnitudes.

In [11]:
master_catalogue_coords = SkyCoord(master_catalogue['ra'], master_catalogue['dec'])

III.b - Comparing J band to 2MASS

The catalogue is cross-matched to 2MASS-PSC withing 0.2 arcsecond. We compare the UKIDSS total J and K magnitudes to those from 2MASS.

The 2MASS magnitudes are “Vega-like” and we have to convert them to AB magnitudes using the zero points provided on this page:

Band Fν - 0 mag (Jy)
J 1594
H 1024
Ks 666.7
In [12]:
# The AB zero point is 3631 Jy
j_2mass_to_ab = 2.5 * np.log10(3631/1595)
k_2mass_to_ab = 2.5 * np.log10(3631/666.7)
In [13]:
twomass = Table.read("../../dmu0/dmu0_2MASS-point-sources/data/2MASS-PSC_SA13.fits")
twomass_coords = SkyCoord(twomass['raj2000'], twomass['dej2000'])

idx, d2d, _ = twomass_coords.match_to_catalog_sky(master_catalogue_coords)
mask = (d2d < 0.2 * u.arcsec)

twomass = twomass[mask]
ml_twomass_idx = idx[mask]
In [14]:
nb_compare_mags(twomass['jmag'] + j_2mass_to_ab, master_catalogue['m_wfcam_j'][ml_twomass_idx],
                labels=("2MASS J", "WFCAM J (total)"))
WFCAM J (total) - 2MASS J:
- Median: 0.01
- Median Absolute Deviation: 0.04
- 1% percentile: -0.7482610212613876
- 99% percentile: 0.20659443177205777

Based on the first run of the above graph it became clear that uhs requires conversion from Vega to AB.

Keeping only sources with good signal to noise ratio

From here, we are only comparing sources with a signal to noise ratio above 3, i.e. roughly we a magnitude error below 0.3.

To make it easier, we are setting to NaN in the catalogue the magnitudes associated with an error above 0.3 so we can't use these magnitudes after the next cell.

In [15]:
for error_column in [_ for _ in master_catalogue.colnames if _.startswith('merr_')]:
    column = error_column.replace("merr", "m")
    keep_mask = np.isfinite(master_catalogue[error_column])
    keep_mask[keep_mask] &= master_catalogue[keep_mask][error_column] <= 0.3
    master_catalogue[column][~keep_mask] = np.nan

IV - Comparing aperture magnitudes to total ones.

In [16]:
nb_ccplots(
    master_catalogue['m_bass_r'],
    master_catalogue['m_ap_bass_r'] - master_catalogue['m_bass_r'],
    "r total magnitude (BASS)", "r aperture mag - total mag (BASS)",
    master_catalogue["stellarity"],
    invert_x=True
)
Number of source used: 6940 / 9799 (70.82%)

V - Color-color and magnitude-color plots

In [17]:
nb_ccplots(
    master_catalogue['m_bass_g'] - master_catalogue['m_bass_r'],
    master_catalogue['m_bass_z'] - master_catalogue['m_wfcam_j'],
    "g - r (BASS)", "z - J (BASS, WFCAM)",
    master_catalogue["stellarity"]
)
Number of source used: 1045 / 9799 (10.66%)