Besançon Galaxy Model

Besançon model of stellar population synthesis of the Galaxy

Welcome to the Besançon Model of the Galaxy web site.

The service is now available using two ways.
You can access the form as in previous version or directly access to parameters in web service mode (a sample Python client program for using the web service can be downloaded).

To access the forms, you must be logged in; create an account if you do not have one yet.

See the description for details about this new version.

You can still access the previous version if you need to.

Other related services are also available:

  • The Mabuls service provides maps of the microlensing events expected, optical depth, time durations, etc. It is available at "Mabuls"
  • The Gravpot16 service is able to compute orbits, assuming the Besancon Galaxy Model gravitational potential (Fernandez-Trincado et al, 2017). Have a look at "GravPot16"
  • Gaia simulations are available at Paris Observatory site and at the CDS (only for the Gaia Universe Model Snapshot "GUMS").

Precomputed star counts are available for those who just need an estimation of the number of stars at a given magnitude and a given direction, in the Johnson V band.

For the Gaia mission, we have computed specific star counts in the G band, using a slightly different model, described in Robin et al (2012) [ADS] and using the DPAC computing tool GOG (Gaia Object Generator, These simulations are available here. These star counts are summarized in this table
# HealPix HealPixBin-l HealPixBin-b Gmagcount3 Gmagcount4 Gmagcount5 Gmagcount6 Gmagcount6 Gmagcount8 Gmagcount9 Gmagcount10 Gmagcount11 Gmagcount12 Gmagcount13 Gmagcount14 Gmagcount15 Gmagcount16 Gmagcount17 Gmagcount18 Gmagcount19 Gmagcount20 
0 45.000000 87.660747 0.000000 0.000000 0.000000 0.000000 1.000000 3.000000 11.000000 38.000000 74.000000 167.000000 341.000000 606.000000 1051.000000 1539.000000 2401.000000 3354.000000 4835.000000 1996.000000 
1 135.000000 87.660747 0.000000 0.000000 0.000000 1.000000 3.000000 8.000000 8.000000 29.000000 73.000000 168.000000 370.000000 624.000000 991.000000 1473.000000 2376.000000 3371.000000 4677.000000 2031.000000 
in healpix sky regions of 8.59 square degree each. They include photometric errors for the end of mission. The Galaxy model follows mainly the thin disc modelling explained in Czekaj et al (2014) [ADS], and the same thick disc, bulge and halo, as in model msp1612 presented above.
Observatoire Aquitain des Sciences de l'Univers
Observatoire des Sciences de l'Univers THETA de Franche-Comté-Bourgogne
Observatoire astronomique de Strasbourg
Laboratoire d'Astrophysique de Bordeaux
Institut UTINAM