Minimize a set of parameters in a single spectrum#

Overview of the configuration keys#

For each key, a short description is given ; for more information, click on the link (name of the key).

data_file : path to the datafile
minimize : in this case must be True
components : a file or a dictionary with the parameters of the components
tuning_info : a dictionary used to specify which telescope(s) to use over a given (list of) frequency range(s); if the ranges are smaller
rms_cal : a file or a dictionary providing noise and calibration information
(v_range and bandwidth) or fit_freq_except ; see Workflow

thresholds : thresholds on the spectroscopic parameters
snr_threshold : when provided, only line with a modeled signal-to-noise ratio greater than this value will be saved.
oversampling : oversampling of the model (for display purposes)
line_shift_kms : if the data are in sky frequency, use this value to search for lines outside the observed range.
tc : value(s) for the continuum
tcmb : temperature of the CMB
max_iter : maximum number of iterations
plot_gui
plot_pdf
v_range
options for the display (to come)

Components setup : for each component, the program finds the list of species
The program reads the file given with data_file
If franges_ghz is provided, data are selected over these frequency ranges
For a given species, the program searches for transitions within the range(s) specified with tuning_info. For display purposes, only transitions within the spectroscopic constraints provided by the user are selected.

Warning

The constraints are only used to select lines to be displayed. The model will always use all the transitions found within a certain frequency range, regardless of the values of their spectroscopic parameters.
Data points used for the fit are:
- either within the velocity ranges provided by the user
- or all points except those in some (small) frequency windows