astrobase.services.trilegal module

This downloads and interacts with galaxy models generated by the TRILEGAL web-form by Prof. Leo Girardi. This module requires the requests and astropy packages only and can be used without astrobase if the accompanying dust.py module is located in the same directory as this module.

If you use this, please cite the TRILEGAL papers:

http://stev.oapd.inaf.it/~webmaster/trilegal_1.6/papers.html

and link to the TRILEGAL website:

http://stev.oapd.inaf.it/cgi-bin/trilegal

The extinction coefficient Av_at_infinity for the requested coordinates is automatically obtained from the 2MASS DUST service at:

http://irsa.ipac.caltech.edu/applications/DUST/

astrobase.services.trilegal.list_trilegal_filtersystems()[source]

This just lists all the filter systems available for TRILEGAL.

astrobase.services.trilegal.query_galcoords(gal_lon, gal_lat, filtersystem='sloan_2mass', field_deg2=1.0, usebinaries=True, extinction_sigma=0.1, magnitude_limit=26.0, maglim_filtercol=4, trilegal_version=1.6, extraparams=None, forcefetch=False, cachedir='~/.astrobase/trilegal-cache', verbose=True, timeout=60.0, refresh=150.0, maxtimeout=700.0)[source]

This queries the TRILEGAL model form, downloads results, and parses them.

Parameters:
  • gal_lon,gal_lat (float) – These are the center galactic longitude and latitude in degrees.
  • filtersystem (str) – This is a key in the TRILEGAL_FILTER_SYSTEMS dict. Use the function astrobase.services.trilegal.list_trilegal_filtersystems() to see a nicely formatted table with the key and description for each of these.
  • field_deg2 (float) – The area of the simulated field in square degrees.
  • usebinaries (bool) – If this is True, binaries will be present in the model results.
  • extinction_sigma (float) – This is the applied std dev around the Av_extinction value for the galactic coordinates requested.
  • magnitude_limit (float) – This is the limiting magnitude of the simulation in the maglim_filtercol band index of the filter system chosen.
  • maglim_filtercol (int) – The index in the filter system list of the magnitude limiting band.
  • trilegal_version (float) – This is the the version of the TRILEGAL form to use. This can usually be left as-is.
  • extraparams (dict or None) –

    This is a dict that can be used to override parameters of the model other than the basic ones used for input to this function. All parameters are listed in TRILEGAL_DEFAULT_PARAMS above. See:

    http://stev.oapd.inaf.it/cgi-bin/trilegal

    for explanations of these parameters.

  • forcefetch (bool) – If this is True, the query will be retried even if cached results for it exist.
  • cachedir (str) – This points to the directory where results will be downloaded.
  • verbose (bool) – If True, will indicate progress and warn of any issues.
  • timeout (float) – This sets the amount of time in seconds to wait for the service to respond to our initial request.
  • refresh (float) – This sets the amount of time in seconds to wait before checking if the result file is available. If the results file isn’t available after refresh seconds have elapsed, the function will wait for refresh seconds continuously, until maxtimeout is reached or the results file becomes available.
  • maxtimeout (float) – The maximum amount of time in seconds to wait for a result to become available after submitting our query request.
Returns:

This returns a dict of the form:

{'params':the input param dict used,
 'extraparams':any extra params used,
 'provenance':'cached' or 'new download',
 'tablefile':the path on disk to the downloaded model text file}

Return type:

dict
astrobase.services.trilegal.query_radecl(ra, decl, filtersystem='sloan_2mass', field_deg2=1.0, usebinaries=True, extinction_sigma=0.1, magnitude_limit=26.0, maglim_filtercol=4, trilegal_version=1.6, extraparams=None, forcefetch=False, cachedir='~/.astrobase/trilegal-cache', verbose=True, timeout=60.0, refresh=150.0, maxtimeout=700.0)[source]

This runs the TRILEGAL query for decimal equatorial coordinates.

Parameters:
  • ra,decl (float) – These are the center equatorial coordinates in decimal degrees
  • filtersystem (str) – This is a key in the TRILEGAL_FILTER_SYSTEMS dict. Use the function astrobase.services.trilegal.list_trilegal_filtersystems() to see a nicely formatted table with the key and description for each of these.
  • field_deg2 (float) – The area of the simulated field in square degrees. This is in the Galactic coordinate system.
  • usebinaries (bool) – If this is True, binaries will be present in the model results.
  • extinction_sigma (float) – This is the applied std dev around the Av_extinction value for the galactic coordinates requested.
  • magnitude_limit (float) – This is the limiting magnitude of the simulation in the maglim_filtercol band index of the filter system chosen.
  • maglim_filtercol (int) – The index in the filter system list of the magnitude limiting band.
  • trilegal_version (float) – This is the the version of the TRILEGAL form to use. This can usually be left as-is.
  • extraparams (dict or None) –

    This is a dict that can be used to override parameters of the model other than the basic ones used for input to this function. All parameters are listed in TRILEGAL_DEFAULT_PARAMS above. See:

    http://stev.oapd.inaf.it/cgi-bin/trilegal

    for explanations of these parameters.

  • forcefetch (bool) – If this is True, the query will be retried even if cached results for it exist.
  • cachedir (str) – This points to the directory where results will be downloaded.
  • verbose (bool) – If True, will indicate progress and warn of any issues.
  • timeout (float) – This sets the amount of time in seconds to wait for the service to respond to our initial request.
  • refresh (float) – This sets the amount of time in seconds to wait before checking if the result file is available. If the results file isn’t available after refresh seconds have elapsed, the function will wait for refresh seconds continuously, until maxtimeout is reached or the results file becomes available.
  • maxtimeout (float) – The maximum amount of time in seconds to wait for a result to become available after submitting our query request.
Returns:

This returns a dict of the form:

{'params':the input param dict used,
 'extraparams':any extra params used,
 'provenance':'cached' or 'new download',
 'tablefile':the path on disk to the downloaded model text file}

Return type:

dict
astrobase.services.trilegal.read_model_table(modelfile)[source]

This reads a downloaded TRILEGAL model file.

Parameters:modelfile (str) – Path to the downloaded model file to read.
Returns:Returns the model table as a Numpy record array.
Return type:np.recarray