ALMA FITS Keywords
The ALMA Keywords Filler (AKF) CASA task 1 is built to generate and eventually ingest in the headers the new FITS keywords that we suggest could be useful for a generic ALMA archive miner. The AKF is a Python-based script that exploits existing CASA tasks and toolkit. Detailed information on the definition of the keywords provided by the AKF is presented in the AKF_v1.2_manual (version under revision after referee report).
In the following, the instructions to install the task are described:
- check that astropy, numpy and pyfits are installed
- untar the AKF.tar file into a directory of your choice (e.g., YourHomeDir/ITALIAN_TOOLS)
- enter in that directory (i.e. cd YourHomeDir/ITALIAN_TOOLS)
- launch CASA and run “buildmytasks” in that directory (i.e. os.system(‘buildmytasks’))
- rename mytasks.py in ITtask_AKF.py (i.e. mv mytasks.py ITtask_AKF.py)
- run the ITtask_AKF.py file (i.e. execfile(‘YourHomeDir/ITALIAN_TOOLS/ITtask_AKF.py’))
- you should be able to run the new task in CASA just doing:
inp AKF or tget AKF
The inputs of the task are:
- imName: it is the input image to process and it is a mandatory parameter to provide;
- kwdlist: it consists of the list of keywords to be calculated. The allowed keywords are those of Sect. 3. If the list is not given (kwdlist=[]), all the implemented keywords will be calculated.
- outfile: the name of the disk file to write the output could be given. If no outfile name is given, the results will be written only to the terminal;
- include: it allows to ingest the calculated keywords in the FITS headers. The default is false which means that no keywords will be added to the headers.
The scientific application of the AKF task is wide.
Here an example of light curves derived using the AKF task for the blazar source J0635-7516 (Bonato et al. 2018)1.
Here is the Python code to produce the above light curves: code_J0635-7516.py;
1 Reference:
→The AKF CASA task: AKF_v1.2.zip
→ ALMA FITS header keywords: a study from the archive User perspective. IRA internal report n. 518;
→ Bonato et al. 2018, MNRAS, 478, 1512, “ALMACAL IV: a catalogue of ALMA calibrator continuum observations“;
Useful link
Astropy installation: http://docs.astropy.org/en/stable/install.html