PHOX is a virtual X-ray observatory designed to obtain synthetic observations from hydro-numerical simulations. It is split into 3, independent units.

Unit 1

The first unit is the most general, in which the emission associated to the gaseous component from the hydrodynamical simulation is calculated, based on a theoretical emission model. The spectral model assumed can be very complicated and account for more realistic descriptions of the emitting gas which are included in up-to-date sophisticated hydro-simulations, such as metallicity, chemical composition and sub-grid turbulent broadening of the emission lines. This first unit has to be executed independently from the others just once per simulation output. The emission of each gas volume is associated with a photon package.

Unit 2

The second unit of the code takes into account the geometry of the forseen observation, the observing time as well as the idealized area of the instrument to be used. Here the projection along a given line of sight is applied and photon energies are corrected for the Doppler Shift.

Unit 3

In the third unit, the detailed instrument properties are taken into account. Here the convolution with the instrument response matrices is done. This unit can be conveniently replaced by any desired X-ray instrument simulator, like the sophisticated tool XISSIM, which has been developed especially to obtain synthetic observations of the Suzaku X-ray Imaging Spectrometer.


This software package is developed by Veronica Biffi in collaboration with Klaus Dolag, Hans Boehringer and Gerard Lemson. A description of the code can be found in Biffi et al. 2012, (MNRAS 420, 3545) and Biffi et al. 2013, ( MNRAS 284, 1395).

Code distribution

To obtain the source code of PHOX and the installation instructions, please send a mail to Veronica Biffi (biffi@sissa.it).

Functionality for Web-Interface using Galformod

This prototype implementation allows you to apply PHOX to one snapshot (z=0.07) of the Magneticum Pathfinder simulations set (Dolag et al, in preparation). The result of unit 2 is returned as a fits file and contains the list of photons selected, assuming a desired exposure time and a nominal collecting area of the chosen instrument. You can select clusters from the list or enter any position within the box which has a side length of 128 Mpc/h. More detailed informations on the actual simulation used can be found in Hirschmann et al. 2013.

Via this service you will actually run unit 2 on our server on a pre-processed output of unit 1. Therefore, if you do not have a Galformod account yet, please send your name and your institution to Gerard Lemson (lemson@mpa-garching.mpg.de) to obtain access to the Galformod portal. A prototype of the web interface is already available.


Contact Veronica Biffi (biffi@sissa.it) in case of questions.