Constants (sitelle.constants)

Introduction

sitelle.constants contains a number of physical constants heavily used in the project.

They can be imported directly from the sitelle.constants sub-package:

>>> from sitelle.constants import M31_CENTER

or, if you want to avoid having to explicitly import all the constants you need, you can simply do:

>>> from sitelle import constants as const

and then subsequently use for example const.M31_CENTER.

Caveats

The FITS_DIR constant is more a convenient variable to avoid typing over and over the path hosting the fits files, but it is not used anywhere in the sitelle module, only in notebooks examples. For now it has been implemented only for B. Launet on different machines.

Once a stable directory structure has been set, it is very useful to avoid typing the whole paths each time:

>>> from sitelle.constants import FITS_DIR
>>> from orcs.process import SpectralCube
>>> SN2_ORCS = SpectralCube(FITS_DIR/'orig/M31_SN2.merged.cm1.1.0.hdf5')
>>> SN2_ORCS.set_wcs(FITS_DIR/'M31_SN2.1.0.ORCS/M31_SN2.1.0.wcs.deep_frame.fits')
>>> SN2_ORCS.set_dxdymaps(FITS_DIR/'M31_SN2.1.0.ORCS/M31_SN2.1.0.wcs.dxmap.fits', FITS_DIR/'M31_SN2.1.0.ORCS/M31_SN2.1.0.wcs.dymap.fits')
>>> SN2_ORCS.correct_wavelength(FITS_DIR/'M31_SN2.1.0.ORCS/M31_SN2.1.0.skymap.fits')

Reference/API

sitelle.constants Module

File defining constants that are heavily used throughout the project.

Attributes:

M31_CENTER : SkyCoord

Center of the galaxy, as defined in Crane et al. (1992). See here how to use this SkyCoord object.

SN2_LINES : list of str

Main line names of SN2 filter : Hbeta, [OIII]4959, [OIII]5007. To get the lines rest positions, use orb.core.Lines.get_line_cm1.

SN3_LINES : list of str

Main line names of SN3 filter : [NII]6548, Halpha,[NII]6583, [SII]6716, [SII]6731

FITS_DIR : Path

The path of the main directory hosting all the fits files. This is really a convenience attribute for B. Launet, but can be ignored for a regular use.