Broadband Config and File Format

Broadband is the program that integrates the data cubes output by mcrx into broadband filter images. It takes the mcrx output file and produces a file containing images of the object in all bands desired, with and without dust.

Broadband takes a configuration filename as its only argument. The configuration file consists of keyword-value pairs which are used to control the behavior of the program.

Config keywords

The required keywords are:

input_file mcrx_000.fits

The input file (created by mcrx). output_file broadband_000.fits The name of the output FITS file where the results are saved. filter_list filters The name of the file containing the names of the filters for which the broadband images are to be calculated. filter_file_directory ~/dust_data/filters/

The directory where the filter bandpass files can be found. Filter_lambda_conversion 1e-10

The conversion factor used to convert the wavelengths in the filter files to the wavelengths of the SED. (The example is appropriate for when filter files are in Angstrom and the SED is in meters.)

Optional keywords are:

redshift

Specifies redshift for which the images should be calculated. Default is 0. calculate_images If this is false, only the integrated magnitudes will be calculated. Default is true. use_lyman_absorption If true, images will take Lyman Alpha forest absorption into account, using the model of Madau (95). Default is turned off.

use_counters false

Specifies whether counters should print to standard out. This is nice if you are running interactively, but makes log files messy for batch jobs. Default is true. use_hpm true Specifies whether the HPM Toolkit should be used for performance analysis. Default is false. CCfits_verbose true Specifies whether CCfits should be in verbose mode, which will print diagnostic messages if there's a problem. However, it will also print messages that look suspicious but are normal, so the default is false.

Output file format

The output file is a FITS file. In order to propagate all the necessary input information, it contains a copy of all the HDU's in the input grid file except the "CAMERAi", "CAMERAi-SCATTER/NONSCATTER/ATTENUATION", "GRIDSTRUCTURE", "LAMBDA", "DEPOSITION","RANDOM_STATE" HDU's. Newer files also contain a copy of the "INTEGRATED_QUANTITIES" HDU, but this is missing in older files. The pHDU has the following keywords set:

FILETYPE "BROADBAND"

The file contains broadband images. DATATYPE "GRID" The data is on a grid (as opposed to a particle set). FILTERCODE "BROADBAND" Specifies the code which was used to calculate the broadband images, as well as the HDU in which the configuration keywords can be found. Currently, only BROADBAND is used here.

HDU "BROADBAND" (or whatever is specified by the FILTERCODE keyword): Contains the input parameters from the configuration file.

HDU "FILTERS": This HDU contains a binary table containing the names of the filters and calculated magnitudes. The table columns are: * filter string

The filter name * lambda_eff double The effective wavelength of the passband * ewidth_lambda double The effective width of the passband in wavelength units. * ewidth_nu double The effective width of the passband in frequency units. * L_lambda_effi double L_lambda,effective for camera i * AB_magi double AB magnitude for camera i * L_lambda_eff_nonscatteri double L_lambda,effective for camera i, without dust * AB_mag_nonscatteri double AB magnitude for camera i without dust

HDU's "CAMERAi-BROADBAND": These HDU's contain data cubes with the broadband images for the appropriate camera. The third dimension enumerates the filters in the FILTERS HDU. They also contain the following keywords: SB_FACTR double Conversion factor from internal units to surface brightness IMUNIT string The unit of the pixel quantities

HDU's "CAMERAi-BROADBAND-NONSCATTER": These HDU's contain data cubes with the broadband images without dust. Apart from this, they are identical to their dusty counterparts.