acis_extract, srclist_filename, /MERGE_OBSERVATIONS, MERGE_NAME=name
, /MERGE_FOR_PB, /MERGE_FOR_POSITION, /MERGE_FOR_PHOTOMETRY, MIN_QUALITY=value
acis_extract, srclist_filename, /MERGE_OBSERVATIONS, /PLOT, CARTOON_TEMPLATE=cartoon_template
idl tee MERGE_OBSERVATIONS.log
eband_lo = [0.5, 0.5, 1.0, 2.0, 4.0, 6.0]
eband_hi = [8.0, 1.0, 2.0, 4.0, 6.0, 8.0]
acis_extract, 'all.srclist', /MERGE_OBSERVATIONS, EBAND_LO=eband_lo, EBAND_HI=eband_hi
acis_extract, 'all.srclist', /MERGE_OBSERVATIONS, /PLOT, CARTOON_TEMPLATE='1875.emap'
- In situations where you wish to construct photometry, spectra, responses, etc. on a subset of the observations you've processed, you can supply an optional obsname parameter (§7.3) after the srclist_filename parameter.
The parameter should be a vector of observation names, e.g.
This unusual mode of execution is not shown in the example above to avoid confusion.
- The optional parameter MERGE_NAME allows the observer to name the merge session; the stage's output files will be structured with an extra directory level using the supplied name, separating those files from the results of other merge sessions.
This parameter is analogous to the optional EXTRACTION_NAME parameter (§7.3) which can be used to retain multiple named extractions.
- EBAND_LO, EBAND_HI (optional) should be vectors defining the desired energy bands (in keV) over which photometry will be performed. If omitted these bands are used:
- The optional parameter OVERLAP_LIMIT (range [0,1], default 0.1) specifies the threshold applied against each extraction's OVERLAP property (assigned by the tool ae_make_catalog; §7.5) to decide if that extraction should be discarded, i.e. not included in the merge (§5.13).
If all extractions have excessive OVERLAP, then the overlap limit for that source is relaxed enough to allow at lease one extraction to be merged, and a warning is printed.
The source properties OVRLP_LO and OVRLP_HI in source.stats record the OVERLAP range of the extractions merged.
- If /MERGE_FOR_PB is specified, then the set of extractions merged will be chosen to optimize source validity (§5.13).
The MIN_NUM_CTS parameter can be used to impose a minimum requirement on SRC_CNTS in the merge, for example to avoid asserting the validity of a source with only two counts (see our AE recipes (§7.1) for example usage).
- If /MERGE_FOR_POSITION is specified, then the set of extractions merged will be chosen to optimize the accuracy of the source position estimate (§5.13).
- If /MERGE_FOR_PHOTOMETRY is specified, then the set of extractions merged will be chosen to optimize source signal-to-noise ratio.
The MIN_QUALITY parameter must be supplied to specify the minimum acceptable ratio between the signal-to-noise ratio achieved by the merge and the optimal signal-to-noise ratio achievable by discarding more extractions (§5.13).
For example, specifying MIN_QUALITY=0.50 means that you want AE to discard observations, risking photometric bias, only when necessary to prevent the signal-to-noise ratio of the merge from dropping below one-half of its optimal value.
- The optional keyword parameter CARTOON_TEMPLATE should be the name of a FITS image that will
be used to define the ``scene'' (image dimensions, pixelization, and placement on the sky) used
to build two cartoon images (cartoon_acis.img, cartoon_sky.img) of the point sources.
The first cartoon uses the ACIS PSF scaled by the flux in the first photometry band;
the second uses a Gaussian PSF of fixed size (currently hard-coded to FWHM=3 image pixels).
For each source the following files are produced:
- a FITS file containing keyword information about the source
- a FITS file containing a multi-ObsId PSF image
- a FITS event list covering the immediate neighborhood of the source
- a FITS table containing the events extracted for the source
- the multi-ObsId source spectrum (not grouped)
- the multi-ObsId background spectrum (not grouped)
- the multi-ObsId ARF
- the multi-ObsId RMF
- a PostScript plot of the light curves and median energy time series for each observation shown on a single ``broken'' time axis.
- a PostScript plot of the light curves and median energy time series for each observation shown on separate time axes.
- a FITS file containing a table of the photometry values described in §5.10
- A DS9 region file showing the extraction polygons for all observations.
- a FITS image containing a cartoon of the field
Several interactive plots show characteristics of the merged extraction; see our AE recipes (§7.1) for descriptions of each.
Next: 7.9 CHECK_POSITIONS Stage
Up: 7 Using ACIS Extract
Previous: 7.7 Adjust BACKSCAL Stage
Penn State Department of Astronomy