ersensmap

erosita/ersensmap-1.0

Summary:

Calculate eROSITA sensitivity maps

Description:

The task ERSENSMAP uses eSASS exposure maps (expimages) and background maps (bkgimages) to calculate the expected detection sensitivity for point sources or extended sources. The detection sensitivity (average source flux required to reach a given detection likelihood) can be calculated for the algorithm employed by the task ERBOX ( method=APER) or for PSF fitting using the Cash statistics (as used by the task ERMLDET, ( method=FIT). The simultaneous detection on several input images can be modelled by providing more than one exposure map and background map. The spectral properties of the sources can be modelled by providing an energy conversion factor for each input image (parameter ecf). When using method="FIT", extended sources can be modelled (parameters extflag, ext, extmodel). As optional output a FITS table containing the cumulative sky area as a function of detectable flux can be written (parameters area_flag, area_table).

Parameters:

expimages [="expmap.fits"] (string) OPTIONAL Input exposure map(s) bkgimages [="expmap.fits"] (string) OPTIONAL Input background map(s) detmasks [="detmask.fits"] (string) OPTIONAL Input detection mask(s) sensimage [="sensmap.fits"] (string) OPTIONAL Output sensitivity map area_table [="areatab.fits"] (string) OPTIONAL Optional output table containing cumulative sky area as function of flux area_flag [="aN"] (boolean) OPTIONAL Write area table ? emin [="500"] (real) OPTIONAL Lower energy boundary for flux calculation [eV] emax [="2000"] (real) OPTIONAL Lower energy boundary for flux calculation [eV] ecf [="1.0E+12"] (real) OPTIONAL Energy conversion factor to convert fluxes to count rates for each input image method [="APER"] (string) OPTIONAL Detection method, for which sensitivity is calculated (APER | FIT). aper_type [="BOX"] (string) OPTIONAL Shape of aperture (BOX | CIRCLE) aper_size [="0.5"] (real) OPTIONAL Aperture size (radius / box half width). aper_size >=1 : Absolute size [image pix], aper_size <1 : given as EEF. likemin[=8.0] (real) OPTIONAL Detection likelihood of faintest detected sources ext[=6.0] (real) OPTIONAL Extent parameter for extended sources [image pixel]. extentmodel[="beta"] (string) OPTIONAL Extent model type ("beta"|"gaussian"). extflag[=N] (boolean) OPTIONAL Model extended sources? (only method="FIT") extlikemin[=6.0] (real) OPTIONAL Likelihood threshold for extent detection (not used in this version). detmask_flag[="Y"] (boolean) OPTIONAL Use detection mask(s) to define regions of interest. shapelet_flag[="Y"] (string) OPTIONAL Use shapelet PSF (not used in this version) photon_flag[="Y"] (boolean) OPTIONAL Calculate sensitivity for photon mode detection (not used in this version)

Input files:

expimages

bkgimages

detmasks

Output files:

sensimage

Output files:

area_table

Examples:

Calculate sensitivity map and area table for 9x9 pixel box apertures:

ersensmap expimages="expmap.fits" \
          bkgimages="bkgmap.fits" \
          detmasks="detmask.fits" \
          sensimage="sensmap_box.fits" \
          emin="500." \
          emax="2000." \
          ecf="1.22246e+12" \
          method="APER" \
          aper_type="BOX" \
          aper_size=4.5 \
          likemin=8. \
          detmask_flag="Y" \
          shapelet_flag="N" \
          photon_flag="N" \
          area_table="survarea_box.fits" \
          area_flag="Y"

Calculate sensitivity map for the detection of extended sources with beta-model (core radius = 5 pix):

ersensmap expimages="expmap.fits" \
          bkgimages="bkgmap.fits" \
          detmasks="detmask.fits" \
          sensimage="sensmap_fit_ext.fits" \
          emin="500." \
          emax="2000." \
          ecf="1.22246e+12" \
          method="FIT" \
          aper_type="BOX" \
          aper_size=4.5 \
          likemin=8. \
          detmask_flag="Y" \
          shapelet_flag="N" \
          photon_flag="N" \
          area_table="survarea_fit.fits" \
          area_flag="Y" \
          ext_flag="Y" \
          extentmodel="beta" \
          ext=5.0