Workflow set-up#
This tutorial details how to set-up the datasets and planetary system to be processed with ANTARESS
.
Datasets#
ANTARESS
can process observed or mock datasets, acquired or generated for multiple epochs with different spectrographs.
Dataset settings are set up in the configuration file, which you should have copied in your working directory.
A list of instruments that can be processed with the workflow, along with their specific designation, is reported in the comments of the ANTARESS_settings() function of the configuration file.
Each visit associated with an instrument can have an arbitrary name, but it must remain consistent throughout the workflow settings.
Information about the retrieval of observed spectral time-series can be found on this page. Once you have retrieved the data, indicate the absolute path to the directories storing each dataset with:
gen_dic['data_dir_list']={instrument:{visit:'path'}}
Information about the generation of mock spectral time-series with ANTARESS
can be found here.
Once you have generated the data, make sure that the workflow is in mock and retrieval modes:
gen_dic['mock_data'] = True
gen_dic['calc_proc_data']= False
And indicate which visits to process through:
mock_dic['visit_def']={instrument:{visit:{}}}
The field associated with a visit is only required when generating the mock dataset.
ANTARESS
is optimally designed to process extracted 2D echelle spectra, which is the default setting for input datasets:
gen_dic['type']={instrument:'spec2D'}
Fast preliminary analysis can however be run on cross-correlation functions (CCFs) time-series, in which case you need to change ‘spec2D’ into ‘CCF’.
Planetary system#
The workflow processes datasets from one stellar system at a time. Multiple planets can be processed together, transiting or not during the epoch of a given dataset.
First, open the copy of the ANTARESS_systems.py file that you saved in your working directory. The file contains a dictionary in which you define the star (star_name) and associated planets (planet_b, planet_c, etc) as:
all_system_params={
star_name:{
'star':{
'st_prop':value},
planet_b:{
'pl_prop':value},
planet_c:{
'pl_prop':value},
}}
The star and planet names are arbitrary, but they must remain consistent throughout the workflow settings. Properties that you must define for the star (st_prop) and planets (pl_prop) are described in details in the comments of the ANTARESS_systems.py file.
Tip
You can define as many planetary systems as you want in the ANTARESS_systems.py file, as the star and planets to be processed are selected through ANTARESS
configuration file.
Then, in your copy of the configuration file define which star you want to process:
gen_dic['star_name']=star_name
All planets that have a significant impact on the Keplerian motion of the star during the observing epochs should be listed in:
gen_dic['kepl_pl'] = [planet_b,planet_c]
The list of planets can be replaced by ‘all’ to directly account for all planets set up in the ANTARESS_systems.py file.
Tip
If a planet induces a constant reflex motion of its star during an observing epoch, for example if it has a long orbital period, it does not need be defined in gen_dic[‘kepl_pl’]. Its contribution will be absorbed in the value that you will derive for the systemic RV of the system in each epoch.
Because ANTARESS
typically processes ground-based datasets obtained during a night, you need to indicate which planet(s) affected the light measured from the system in a given observing epoch:
gen_dic['studied_pl'] = {planet_b:{instrument:[visit]}}
Instruments and visits must match those you indicated in gen_dic[‘data_dir_list’]. If a planet emission or its absorption of the stellar light are negligible during an observing epoch, or if they do not affect the part of the data that you intend to study, there is no need to associate the planet to this epoch in gen_dic[‘studied_pl’].
Planet-to-star radius ratios RpRs must be defined for all planets in gen_dic[‘studied_pl’] using the configuration file:
data_dic['DI']['system_prop']={
'achrom':{'LD':[LD_law],'LD_u1':[u1],'LD_u2':[u2],..,planet_b:[RpRs_b],planet_c:[RpRs_c]}}
This field also defines the broadband intensity variations of the stellar photosphere, through a given limb-darkening law LD and associated coefficients LD_ui. More information about this field are available in the configuration file.
Note
Broadband stellar intensity variations and planet-to-star radius ratios are controlled through the configuration file rather than the system property file because they can be defined chromatically through an optional sub-field chrom. This is to allow for possible variations of the stellar intensity and planet apparent size at low medium frequencies, for example if the planetary atmosphere yields strong Rayleigh scattering.