4. Running

To run the code simply position a cluster’s photometric data file in the input/ folder, modify the params_input.dat file to both inform the code of the distribution of columns in your photometric file and set the values for each function within the code. Photometric files can also be stored in input/ inside a sub-folder.

Every file inside the input/ folder (inside or outside a sub-folder) will be processed by ASteCA, with the exception of the membership probabilities files that end with a _memb.dat extension (see Sect. 10).

Once the file(s) are in place and the params_input.dat file correctly modified, the code can be executed with the command:

(asteca) $ python asteca.py

This should work both in Linux based systems and OS X (Mac), but I’ve only tested it with Linux (since that’s what I use).

The CLUSTER.DAT file located in the input/ folder contains a synthetic open cluster generated via the MASSCLEAN package with the following parameter values:

M = 500 Mo
z = 0.008
log(age) = 8.0
E(B-V) = 0.32 (Av = 1.0)
(m-M)o = 12.32 (d = 3 kpc)

and serves as an example cluster to be analyzed with ASteCA.

4.1. Theoretical isochrones

ASteCA needs at least one set of theoretical isochrones stored in the isochrones/ folder, to be able to apply the best-fit function that estimates the clusters’ parameters. Currently, the only isochrone files supported are those obtained via the CMD service (Girardi et al. 2002), but any set can in theory be used (with some changes made to the code). Please contact me if you wish to use a different set of theoretical isochrones.

The isochrones can be downloaded manually or the package ezPadova-2 can be used to automatically fetch them from the site. I describe both possibilities below.


The current version of the code supports all the photometric systems from available at the CMD service.

4.1.1. Manual download

They isochrone files must follow a naming convention and be stored in a sub-folder inside the isohrones/ folder, also named according to a convention that makes them readable and identifiable to the code.

The steps to manually download and store the files are:

1. The CMD isochrones files must be downloaded using the Sequence of isochrones of constant metallicity, Z option. That is, isochrones of the same metallicity must all be stored in the same file.

2. Each file must have the name of the metallicity that characterizes it. For example, if you download a sequence of isochrones with metallicity z=0.019, then the file should be called 0.019.dat, or 0_019.dat, or 0.0190.dat, or 0_019000.dat, etc.

This means that the file name can contain either a point or an underscore separating the decimal portion of the metallicity value. The number of zeros at the end of the value in the name does not matter. This is necessary because the code takes the metallicity value directly from the file name.

3. The theoretical isochrones files must be stored in a sub-folder of isochrones/, with the naming convention: parsecXX_YYY (if PARSEC isochrones are used). In this name, XX is 10, 11 or 12 depending on the version of PARSEC used (1.0, 1.1 or 1.2S, respectively) and ‘YYYY’ is ubvi, wash or 2MASS, depending on the system chosen to generate the isochrones.

For example, if the PARSEC v1.2S tracks and the UBVRIJHK (cf. Maiz-Apellaniz 2006 + Bessell 1990) system is selected, the name of the sub-folder where the isochrones must be stored would be: parsec12_ubvi.

4.1.2. Automatic download

To avoid having to download each isochrone file by hand, I’ve written the ezPADOVA-2 code 1 which can downloaded from:

This code takes care of downloading the isochrones for a given range of metallicities, storing them in files named following the above mentioned naming convention, and place them inside a folder also with the correct name.

This way, once this code finishes you can just cut the generated folder and paste it inside the isochrones/ folder in ASteCA.

[1]Fork of original ezpadova code by Morgan Fouesneau (https://github.com/mfouesneau/ezpadova).