This package consists of a collection of XMM-Newton Extended Source Analysis Software (XMM-ESAS) tasks originally developed by Snowden, et al. and released as a standalone package in 2008. This package follows the methods outlined in Snowden et al. (2008)[1] for the analysis of extended objects and the diffuse background using XMM-Newton EPIC MOS and pn observations.
Two separate features are incorporated into ESAS; the capability of creating model quiescent particle background spectra (Kuntz & Snowden 2008)[1] for user defined regions of the detectors and the capability of creating background subtracted and exposure corrected images. Also included in the XMM-ESAS package is software to mosaic multiple and not necessarily coaligned observations of regions on the sky.
This package consists of perl scripts and FORTRAN-90 routines. The perl scrips tie together both the FORTRAN routines and various XMM SAS tasks and FTOOLS to produce the images, spectra and filtered eventlists for analysis.
Descriptions for each FORTRAN routine and perl script are as follows:
FORTRAN routines:
adapt adaptively smooths background subtracted and exposure corrected images. For each unmasked pixel, the program will average neighboring pixels within a circle of increasing radius until a selected number of counts is reached. The original pixel is then given the average surface brightness for the pixels within the circle. Images can also be binned before smoothing.
adapt_merge adaptively smooths background subtracted and exposure corrected mosaicked images. For each unmasked pixel, the program will average neighboring pixels within a circle of increasing radius until a selected number of counts from the count image is reached. The original pixel is then given the average surface brightness for the pixels within the circle. The images can also be binnedbefore smoothing.
bin_image produces binned count rate and count-rate uncertainty images of single observations. It can use either individual exposures or the output of the program comp which can merge all of the exposures associated with a single ObsID. For each unmasked and binned pixel, the program will determine the average count rate and the count rate uncertainty. The assumption is that the uncertainty is dominated by the counting statistics and the the systematics of the background modeling. Binning by 1, 2, 3, 4, 6, or 9 can be selected.
comb combines the various MOS1 and MOS2 images from a single observation, as well as images from multiple exposures into single count, exposure, model particle background, and soft proton background images.
make_mask is called by the perl script cheese in mode=2 to create a cheese mask from the filtered source list.
merge_comp_xmm creates a merged (mosaicked) count, exposure, particle back-ground, and soft proton images for multiple observations and exposures.
merge_source_list creates a master list of sources detected from a list of observations which have been processed to the point of a creating an emldetect source list. Sources are compared and those within 2" of each other have the one with the lower flux thrown out. It assumes that the source detection has been in two bands, 0.4-1.25 keV and 2.0-7.2 keV, which can be produced by cheese-bands in the default mode.
mos_back takes the output of the perl script mos-spectra and creates quiescent particle background spectra and images in detector coordinates, as selected, for EPIC MOS data.
point_source calculates the appropriate Xspec normalization for the extragalactic background given the user-selected point-source exclusion threshold.
pn_back takes the output of the perl script pn-spectra and creates quiescent particle background spectra and images in detector coordinates, as selected, for EPIC PN data.
proton produces images in detector coordinates of the model residual soft proton contamination. To do so, it uses the fitted values of the soft proton component from Xspec and standard detector maps.
proton_scale extracts the appropriate scale factors for the solid angle and relative soft proton contributions to include in spectral fitting.
rot_det_sky is called by the PERL script rot-im-det-sky. It rotates the particle background images output from mos-back and pn-back and the soft proton images output from proton, which are in detector coordinates, into images in sky coordinates.
sp_partial scales the soft proton spectral fit results from a limited region of the detector to the full field of view. This allows the user to fit for the soft proton contamination in regions of lower surface brightness (e.g., an outer annulus for a cluster of galaxies) which can significantly improve the accuracy of the fit.
PERL routines:
clean deletes a number of intermediate and unneeded files after the processing is complete.
cheese does source detection and creates cheese masks for point-source masking during image processing. Cheese allows the user to set a flux threshold over the field for the removal of the source contributions to the spectra as well as the images.
mos-filter is the script which does the initial processing of the MOS ODF data. It runs the SAS tasks cifbuild, odfingest, and emchain (along with a few others) to set up for SAS processing and to create calibrated photon event files. mos-filter then filters and cleans the event files of soft proton contamination using the SAS task espfilt. Along with a filtered event file it produces a QDP plot file showing the observation light curves and indicates the accepted time intervals.
mos-spectra processes the filtered event files to produce a set of intermediate files for the production of background spectra and images. mos-spectra also produces source spectra and the appropriate Redistribution Matrix Files, RMFs, and Ancillary Region Files, ARFs, for spectral analysis.
pn-filter is the initial processing script for pn data and it performs the same tasks as mos-filter for MOS data. It substitutes the task epchain for emchain and in addition each exposure is processed in both normal and out-of-time (OOT) modes.
pn-spectra provides the same functions for pn data as mos-spectra provides for the MOS. However, it also creates spectra from the out-of-time processing.
rot-im-det-sky rotates both the model particle and soft proton background images from detector coordinates to sky coordinates.