Moments

class turbustat.moments.Moments(cube, scale=None, moment_method='slice')

Bases: object

A unified approach to deriving the noise level in a cube, applying a mask, and deriving moments along with their errors. All the heavy lifting is done with spectral_cube.

Parameters:

cube : SpectralCube or str

Either a SpectralCube object, or the filename of a cube readable by spectral-cube.

scale : Quantity, optional

The noise level in the cube. Used to estimate uncertainties of the moment maps.

moment_method : {‘slice’, ‘cube’, ‘ray’}, optional

The method to use for creating the moments. See the spectral-cube docs for an explanation of the differences.

Attributes Summary

linewidth
linewidth_err
moment0
moment0_err
moment1
moment1_err
scale

Methods Summary

all_moment_errs(self)
all_moments(self)
apply_mask(self, mask)	Apply a mask to the cube.
from_fits(fits_name[, moments_prefix, …])	Load pre-made moment arrays given a cube name.
get_prop_hdrs(self)	Generate headers for the moments.
make_moment_errors(self[, axis, scale])	Calculate the errors in the moments.
make_moments(self[, axis, units])	Calculate the moments.
to_dict(self)	Returns a dictionary with the cube and the property arrays.
to_fits(self[, save_name])	Save the property arrays as fits files.

Attributes Documentation

linewidth

linewidth_err

moment0

moment0_err

moment1

moment1_err

scale

Methods Documentation

all_moment_errs(self)

all_moments(self)

apply_mask(self, mask)

Apply a mask to the cube.

Parameters:

mask : spectral-cube Mask or numpy.ndarray, optional

The mask to be applied to the data. If None is given, RadioMask is used with its default settings.

static from_fits(fits_name, moments_prefix=None, moments_path=None, mask_name=None, moment0=None, centroid=None, linewidth=None, scale=None)

Load pre-made moment arrays given a cube name. Saved moments must match the naming of the cube for the automatic loading to work (e.g. a cube called test.fits will have a moment 0 array with the name test_moment0.fits). Otherwise, specify a path to one of the keyword arguments.

Parameters:

fits_name : str

Filename of the cube or a SpectralCube object. If a filename is given, it is also used as the prefix to the saved moment files.

moments_prefix : str, optional

If a SpectralCube object is given in fits_name, the prefix for the saved files can be provided here.

moments_path : str, optional

Path to where the moments are saved.

mask_name : str, optional

Filename of a saved mask to be applied to the data.

moment0 : str, optional

Filename of the moment0 array. Use if naming scheme is not valid for automatic loading.

centroid : str, optional

Filename of the centroid array. Use if naming scheme is not valid for automatic loading.

linewidth : str, optional

Filename of the linewidth array. Use if naming scheme is not valid for automatic loading.

scale : Quantity, optional

The noise level in the cube. Overrides estimation using signal_id

get_prop_hdrs(self)

Generate headers for the moments.

make_moment_errors(self, axis=0, scale=None)

Calculate the errors in the moments.

Parameters:

axis : int, optional

The axis to calculate the moments along.

make_moments(self, axis=0, units=True)

Calculate the moments.

Parameters:

axis : int, optional

The axis to calculate the moments along.

units : bool, optional

If enabled, the units of the arrays are kept.

to_dict(self)

Returns a dictionary with the cube and the property arrays.

to_fits(self, save_name=None)

Save the property arrays as fits files.

Parameters:

save_name : str, optional

Prefix to use when saving the moment arrays. If None is given, ‘default’ is used.