# General Information Regarding the Command-Line Interface to SOXS¶

## Path to the Response Files¶

To use either the instrument_simulator or simulate_spectrum command-line scripts, it is necessary to download the response files from the Response Files page and place them in an appropriate location, of which there are two. The first is simply to place the response files needed for the instrument simulator in the current working directory from which you run SOXS. However, it is probably more convenient to place the response files in a default path, which can be specified in the SOXS configuration file like this:

[soxs]
response_path = /Users/jzuhone/Data/soxs_responses


See SOXS Configuration File for more information about the location of the configuration file and how to set its parameters.

## Special Argument Handling for Quantities with Units¶

Many arguments in the command line scripts which have units can take a special format which allows one to specify that particular quantity in the units desired by the user. For example, the make_point_source script has the arguments exp_time and area, which assume the default units of seconds and $$\rm{cm^2}$$, respectively, if one supplies floating-point numbers:

[~]$make_point_source pt_src src1 20.0 -32.0 pt_src_spectrum.dat 100000.0 --overwrite --area=30000.0  but can take other units, like ks and $$\rm{m^2}$$, in this format: [~]$ make_point_source pt_src src1 20.0 -32.0 pt_src_spectrum.dat 100.0,ks --overwrite --area=3.0,m**2


Since the quantities are the same but in different units, these two calls would be equivalent.

The following arguments used in the command line scripts accept values with a unit specification:

### Parameters Used in Many Scripts¶

• exp_time: Exposure time, default units of seconds
• area: Collecting area, default units of $$\rm{cm}^2$$
• fov: Field of view, default units of arcminutes
• emin: Minimum energy, default units of keV
• emax: Minimum energy, default units of keV
• nH: Foreground galactic absorption column, default units of $$10^{22} \rm{atoms/cm^2}$$

### Parameters Used in Command Line Scripts for Spatial Models¶

• ra0: Central right ascension, default units of degrees
• dec0: Central right ascension, default units of degrees
• theta: Rotation angle, default units of degrees

### Parameters Used in make_thermal_spectrum¶

• kT: Temperature, default units of keV
• velocity: Velocity broadening parameter, default units of km/s

### Parameters Used in make_annulus_source¶

• r_in: Inner radius of annulus, default units of arcseconds
• r_out: Inner radius of annulus, default units of arcseconds

### Parameters Used in make_beta_model¶

• r_c: Core radius parameter, default units of arcseconds

### Parameters Used in make_rectangle_source¶

• width: Width of rectangle, default units of arcseconds
• height: Width of rectangle, default units of arcseconds

## Random Number Generation¶

Many routines in SOXS require generating random numbers for energies, sky positions, spectral channels, etc. By default, for every SOXS run this will be a different set of random numbers. It is often the case, however, that one wants to use a consistent, repeatable set of random numbers to reproduce results exactly. For this, many of the command-line scripts in SOXS take a random_seed optional argument, which has a default of None, but if set to an integer will use this value as a random seed.

For example, to use a consistent random seed in generating positions and energies for an annulus source, one would set the random seed like this:

make_annulus_source my_cat annulus 30.0 45.0 10.0 30.0 thermal_spec.dat 100.0,ks --random_seed=24


Check the documentation for the various command line scripts to see which functions have the random_seed argument.