PanSTARRS - WISE crossmatch: Pre-configure the ML parameters

In this step we will prepare the auxiliary variables used for the ML



In [1]:

    
import numpy as np
from astropy.table import Table
from astropy import units as u
from astropy.coordinates import SkyCoord
import pickle



In [2]:

    
from mltier1 import get_center, get_n_m, estimate_q_m, Field



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%pylab inline









    



Populating the interactive namespace from numpy and matplotlib



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field = Field(170.0, 190.0, 45.5, 56.5)

Load the data

Load the catalogues



In [5]:

    
panstarrs_full = Table.read("panstarrs_u2.fits")



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wise_full = Table.read("wise_u2.fits")



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panstarrs = field.filter_catalogue(
    panstarrs_full, 
    colnames=("raMean", "decMean"))



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# Free memory
del panstarrs_full



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wise = field.filter_catalogue(
    wise_full, 
    colnames=("raWise", "decWise"))



In [10]:

    
# Free memory
del wise_full

Coordinates

As we will use the coordinates to make a cross-match we to load them



In [11]:

    
coords_panstarrs = SkyCoord(panstarrs['raMean'], panstarrs['decMean'], unit=(u.deg, u.deg), frame='icrs')



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coords_wise = SkyCoord(wise['raWise'], wise['decWise'], unit=(u.deg, u.deg), frame='icrs')

Compute the ML parameters

Number of sources per magnitude in i-band



In [13]:

    
bin_list = np.linspace(12., 30., 1801)



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center = get_center(bin_list)



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n_m = get_n_m(panstarrs["i"], bin_list, field.area)

Number of sources per magnitude per unit area in the selected region (cumulative distribution). This sets the number of background sources. The units of this are N/(square arcsec) per magnitude.



In [16]:

    
plot(center, n_m);

Compute real(m) and q(m)

The first step is to crossmatch the catalogues to make an estimation



In [17]:

    
radius = 5 # arcseconds



In [18]:

    
q_m = estimate_q_m(panstarrs["i"], bin_list, n_m, coords_wise, coords_panstarrs, radius=5)



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plot(center, q_m);

Estimated $Q_0$



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q0 = 0.62

Save the parameters



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pickle.dump([bin_list, center, q0, n_m, q_m], open("pw_params.pckl", 'wb'))



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