Making cutouts from a single or multiple bands

The first thing we will do is load the ID=718 z=14.63 JOF candidate from Robertson et al. 2023, as done in, for example, the galaxy selection notebook.

[1]:

# imports
import astropy.units as u
import numpy as np
from copy import deepcopy
from galfind import Catalogue, Band_Cutout, Multiple_Band_Cutout
from galfind.Data import morgan_version_to_dir

Reading GALFIND config file from: /nvme/scratch/work/austind/GALFIND/galfind/../configs/galfind_config.ini

WARNING:galfind:Aperture corrections for VISTA not found in /nvme/scratch/work/austind/GALFIND/galfind/Aperture_corrections/VISTA_aper_corr.txt
WARNING:galfind:Aperture corrections for VISTA not found in /nvme/scratch/work/austind/GALFIND/galfind/Aperture_corrections/VISTA_aper_corr.txt

Failed to `import dust_attenuation`
Install from the repo with $ pip install git+https://github.com/karllark/dust_attenuation.git

[2]:

survey = "JOF"
version = "v11"
instrument_names = ["NIRCam"]
aper_diams = [0.32] * u.arcsec
forced_phot_band = ["F277W", "F356W", "F444W"]
min_flux_pc_err = 10.

JOF_cat = Catalogue.pipeline(
    survey,
    version,
    instrument_names = instrument_names,
    version_to_dir_dict = morgan_version_to_dir,
    aper_diams = aper_diams,
    forced_phot_band = forced_phot_band,
    min_flux_pc_err = min_flux_pc_err
)
# TODO: Smooth galaxy load-in
# from Robertson et al. 2023
z14_gal = JOF_cat[717]

INFO:galfind:Loaded aper_diams=<Quantity [0.32] arcsec> for F277W+F356W+F444W
INFO:galfind:Combined mask for NIRCam/F277W+F356W+F444W already exists at /raid/scratch/work/austind/GALFIND_WORK/Masks/JOF/combined/JOF_F277W+F356W+F444W_auto.fits
WARNING: hdu= was not specified but multiple tables are present, reading in first available table (hdu=1) [astropy.io.fits.connect]
WARNING:astroquery:hdu= was not specified but multiple tables are present, reading in first available table (hdu=1)
WARNING:galfind:Aperture correction columns already in /raid/scratch/work/austind/GALFIND_WORK/Catalogues/v11/NIRCam/JOF/(0.32)as/JOF_MASTER_Sel-F277W+F356W+F444W_v11.fits
Calculating depths:   0%|          | 0/15 [00:00<?, ?it/s]
INFO:galfind:Calculated/loaded depths for JOF v11 NIRCam
INFO:galfind:Local depth columns already exist in /raid/scratch/work/austind/GALFIND_WORK/Catalogues/v11/NIRCam/JOF/(0.32)as/JOF_MASTER_Sel-F277W+F356W+F444W_v11.fits
INFO:galfind:Loaded 'has_data_mask' from /raid/scratch/work/austind/GALFIND_WORK/Masks/JOF/has_data_mask/JOF_MASTER_Sel-F277W+F356W+F444W_v11.h5
INFO:galfind:Making JOF v11 JOF_MASTER_Sel-F277W+F356W+F444W_v11 catalogue!
WARNING:galfind:cat_aper_diams not in kwargs.keys()=dict_keys(['ZP', 'min_flux_pc_err'])! Setting to aper_diams=<Quantity [0.32] arcsec>
WARNING:galfind:cat_aper_diams not in kwargs.keys()=dict_keys(['ZP', 'min_flux_pc_err'])! Setting to aper_diams=<Quantity [0.32] arcsec>
WARNING:galfind:cat_aper_diams not in kwargs.keys()=dict_keys([])! Setting to aper_diams=<Quantity [0.32] arcsec>
INFO:galfind:Made /raid/scratch/work/austind/GALFIND_WORK/Catalogues/v11/NIRCam/JOF/(0.32)as/JOF_MASTER_Sel-F277W+F356W+F444W_v11.fits catalogue!

Example 1: Making (and plotting) a single band cutout

Now that we have loaded the galaxy in question, we will first produce and plot the F444W cutout for this source. There are various options regarding the size of the cutout to make, as well as various other plotting options (i.e. changing colourmaps, scaling, adding SNR labels, etc).

[3]:

JOF_f444w_data = JOF_cat.data["F444W"]
z14_f444w_cutout = Band_Cutout.from_gal_band_data( \
    z14_gal, JOF_f444w_data, cutout_size = 0.96 * u.arcsec, overwrite = True)

print(z14_f444w_cutout)

WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F444W
INFO:galfind:Created cutout for SEG in F444W
INFO:galfind:Created cutout for RMS_ERR in F444W
INFO:galfind:Created cutout for WHT in F444W
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F444W/data/718.fits

****************************************
BAND_CUTOUT(718,F444W,0.96as):
****************************************
Cutout path: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F444W/data/718.fits
Meta:
----------
SIMPLE: True
BITPIX: 8
NAXIS: 0
EXTEND: True
ID: 718
SURVEY: JOF
VERSION: v11
RA: 53.10762649807784
DEC: -27.86013118667997
SIZE_AS: 0.96
SIZE_PIX: 32.0
****************************************

From the galfind logger information, we see that an 0.96as F444W cutout has been made and saved for this source, which contains SCI, SEG, WHT, and RMS_ERR extensions. WCS data is stored in the header of each of these extensions. We can load these explicitly by calling Band_Cutout_Base.load(), which Band_Cutout inherits.

[4]:

z14_f444w_cutout_raw_data = z14_f444w_cutout.load(hdu_name = None)
z14_f444w_cutout_sci_data = z14_f444w_cutout.load(hdu_name = "SCI")

if z14_f444w_cutout_raw_data["SCI"][0] == z14_f444w_cutout_sci_data[0]:
    print("Header is the same!")
else:
    print("Header is different!")
try:
    np.testing.assert_array_equal(
        z14_f444w_cutout_raw_data["SCI"][1],
        z14_f444w_cutout_sci_data[1]
    )
    print("Data is the same!")
except:
    print("Data is different!")

Header is the same!
Data is the same!

Now let’s have a go at plotting the F444W cutout from this galaxy using the default plotting function (other than the default show = False, which has now been set to True for illustrative purposes).

[5]:

z14_f444w_cutout.plot(
    ax = None,
    plot_type = "SCI",
    imshow_kwargs = {"norm": "linear", "cmap": "magma"},
    norm_kwargs = {},
    plot_regions = [],
    scalebars = [],
    label_kwargs = {},
    show = True,
    save = True,
)

INFO:galfind:Saved png cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F444W/png/718.png

../_images/cutouts_single_band_cutouts_8_1.png

Now that we have seen what the default plotting code outputs, now let’s have a look at how we can alter the default plotting kwargs to improve the plot appearance.

[6]:

z14_f444w_cutout.plot(
    ax = None,
    plot_type = "SCI",
    imshow_kwargs = {"norm": "EPOCHS", "cmap": "Greys_r"},
    norm_kwargs = {"high_dyn_range": False, "SNR": None},
    plot_regions = [{"aper_diam": 0.32 * u.arcsec, "color": "green", "ls": "-", "lw": 3.}],
    scalebars = [],
    label_kwargs = {"xpos": 0.05, "ypos": 0.95, "ha": "left", "fontsize": "large", "c": "red"},
    show = True,
    save = True,
)

INFO:galfind:Saved png cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F444W/png/718.png

../_images/cutouts_single_band_cutouts_10_1.png

In the above cell we have plotted the extraction aperture for this source using the aper_diam dictionary key, although there also exists an option to supply the plot region explicitly here. Since plot_radii takes a list, any appropriate matplotlib.pyplot.patches.Ellipse object (of which patches.Circle is a child) inserted here will also be plotted. Let’s try, for example, plotting the SExtractor fitting F444W Kron aperture for this source. It is worth noting that should the region be centred at (-99., -99.) that this will be by default set at the X/Y co-ordinates of the cutout/source centre.

[7]:

from matplotlib.patches import Ellipse
import matplotlib.patheffects as pe
# update catalogue with Kron apertures from the fits catalogue
# get updated galaxy from catalogue
# extract A_IMAGE, B_IMAGE, THETA_IMAGE from fits catalogue and produce elliptical Kron aperture
kron_kwargs = {"ls": "-", "color": "blue", "path_effects": [pe.withStroke(linewidth = 3., foreground = "white")]}
kron_aperture = Ellipse((-99., -99.), width = 10., height = 5., angle = 25., **kron_kwargs) #z14_gal.sex_A["F444W"], height = z14_gal.sex_B["F444W"], angle = z14_gal.sex_theta["F444W"])
# plot
z14_f444w_cutout.plot(plot_regions = [{"aper_diam": 0.32 * u.arcsec}, kron_aperture])

INFO:galfind:Saved png cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F444W/png/718.png

../_images/cutouts_single_band_cutouts_12_1.png

Woo! Now let’s have a go at creating a Band_Data object using the other available class method, from_band_data_skycoord(). This method avoids the need to load in a Galaxy object at all. All that is required is a Band_Data object which stores the data to plot, an astropy SkyCoord object storing the RA/DEC sky position, and, as usual, a cutout size.

[8]:

# code to run from_band_data_skycoord

Example 2: Making and plotting multiple cutouts simultaneously

Fantastic! We have got the hang of plotting a single cutout. Fairly straightforwards right? Now we’ll construct a Multiple_Band_Cutout, which stores an array of Band_Cutout objects for a single (or stacked) source. We will visit the stacking of galaxy cutouts in the stacking notebook, although for now we will use the from_gal_data() class method to instantiate our Multiple_Band_Cutout object directly from a single galaxy.

[9]:

z14_cutouts = Multiple_Band_Cutout.from_gal_data(z14_gal, JOF_cat.data, cutout_size = 0.96 * u.arcsec, overwrite = True)

WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F090W
INFO:galfind:Created cutout for SEG in F090W
INFO:galfind:Created cutout for RMS_ERR in F090W
INFO:galfind:Created cutout for WHT in F090W
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F090W/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F115W
INFO:galfind:Created cutout for SEG in F115W
INFO:galfind:Created cutout for RMS_ERR in F115W
INFO:galfind:Created cutout for WHT in F115W
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F115W/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F150W
INFO:galfind:Created cutout for SEG in F150W
INFO:galfind:Created cutout for RMS_ERR in F150W
INFO:galfind:Created cutout for WHT in F150W
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F150W/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F162M
INFO:galfind:Created cutout for SEG in F162M
INFO:galfind:Created cutout for RMS_ERR in F162M
INFO:galfind:Created cutout for WHT in F162M
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F162M/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F182M
INFO:galfind:Created cutout for SEG in F182M
INFO:galfind:Created cutout for RMS_ERR in F182M
INFO:galfind:Created cutout for WHT in F182M
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F182M/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F200W
INFO:galfind:Created cutout for SEG in F200W
INFO:galfind:Created cutout for RMS_ERR in F200W
INFO:galfind:Created cutout for WHT in F200W
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F200W/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F210M
INFO:galfind:Created cutout for SEG in F210M
INFO:galfind:Created cutout for RMS_ERR in F210M
INFO:galfind:Created cutout for WHT in F210M
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F210M/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F250M
INFO:galfind:Created cutout for SEG in F250M
INFO:galfind:Created cutout for RMS_ERR in F250M
INFO:galfind:Created cutout for WHT in F250M
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F250M/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F277W
INFO:galfind:Created cutout for SEG in F277W
INFO:galfind:Created cutout for RMS_ERR in F277W
INFO:galfind:Created cutout for WHT in F277W
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F277W/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F300M
INFO:galfind:Created cutout for SEG in F300M
INFO:galfind:Created cutout for RMS_ERR in F300M
INFO:galfind:Created cutout for WHT in F300M
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F300M/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F335M
INFO:galfind:Created cutout for SEG in F335M
INFO:galfind:Created cutout for RMS_ERR in F335M
INFO:galfind:Created cutout for WHT in F335M
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F335M/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F356W
INFO:galfind:Created cutout for SEG in F356W
INFO:galfind:Created cutout for RMS_ERR in F356W
INFO:galfind:Created cutout for WHT in F356W
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F356W/data/718.fits
WARNING: FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'. [astropy.wcs.wcs]
WARNING:astroquery:FITSFixedWarning: 'obsfix' made the change 'Set OBSGEO-L to    39.276914 from OBSGEO-[XYZ].
Set OBSGEO-B to    29.758199 from OBSGEO-[XYZ].
Set OBSGEO-H to 1287432120.418 from OBSGEO-[XYZ]'.
INFO:galfind:Created cutout for SCI in F410M
INFO:galfind:Created cutout for SEG in F410M
INFO:galfind:Created cutout for RMS_ERR in F410M
INFO:galfind:Created cutout for WHT in F410M
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F410M/data/718.fits
INFO:galfind:Created cutout for SCI in F444W
INFO:galfind:Created cutout for SEG in F444W
INFO:galfind:Created cutout for RMS_ERR in F444W
INFO:galfind:Created cutout for WHT in F444W
INFO:galfind:Saved fits cutout to: /raid/scratch/work/austind/GALFIND_WORK/Cutouts/v11/JOF/0.96as/F444W/data/718.fits

The logging output usefully lets us know that we have created the cutouts appropriately. Let’s see what data is shown when we print this object out.

[10]:

print(z14_cutouts)

<galfind.Cutout.Multiple_Band_Cutout object at 0x7f8878f845b0>

We now can see exactly what cutout data is stored, which can be especially useful when dealing with a large number of photometric bands. In some cases it may also be useful to be able to create this object simply by adding together many Band_Data objects. We overload the Band_Data and Multiple_Band_Data __add__ and __sub__ operators for exactly this purpose.

[11]:

# code for __add__, __sub__, and __eq__ methods

We can see that our new Multiple_Band_Cutout object that we have constructed is identical to the one created using the class constructor method directly.

Let’s now look at how we can plot the data stored in this object by calling the plot() function. This first appropriately sets up a figure and axes according to how many cutouts are stored, and then iteratively calls Band_Cutout_Base.plot() for each Band_Cutout/Stacked_Band_Cutout in Multiple_Band_Cutout.

[12]:

z14_cutouts.plot(
    n_rows = 1,
    fig_scaling = 1.5,
    show = True,
    save = True,
    )

../_images/cutouts_single_band_cutouts_22_0.png

Yet again our first attempt at plotting has yielded the default (or most basic) implementation of the plotting code. Below we shall adjust some of these parameters and see how the output plot differs.

[13]:

z14_cutouts.plot(
    n_rows = 2,
    fig_scaling = 1.5,
    imshow_kwargs = {"cmap": "viridis"},
    split_by_instr = True,
    show = True,
    save = True,
    )

../_images/cutouts_single_band_cutouts_24_0.png

Let’s say you also want to make a plot using a colormap that makes it extremely challenging for colorblind people to see, then you can do. Below we use jet_r.

[14]:

z14_cutouts.plot(
    n_rows = 4,
    fig_scaling = 1.5,
    split_by_instr = True,
    imshow_kwargs = {"cmap": "jet_r", "norm": "EPOCHS"},
    norm_kwargs = {"high_dyn_range": False, "SNR": None},
    show = True,
    save = True,
    )

../_images/cutouts_single_band_cutouts_26_0.png