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: http://xmm.vilspa.esa.es/sas/6.5.0/doc/lccorr/node18.html
Дата изменения: Tue Aug 16 09:00:09 2005 Дата индексирования: Sat Dec 22 08:41:21 2007 Кодировка: |
Parameter | Mand | Type | Default | Constraints |
srctsset | yes | dataset | ||
Name of the input timeseries.
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eventset | yes | dataset | ||
Name of the whole-camera event list (for either MOS1, 2 or PN, as appropriate).
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withbkgtsset | no | boolean | no | |
Look for a bkg timeseries name on the command line.
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bkgtsset | no | dataset | bkg_ts.ds | |
Name of the input local background timeseries.
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bkgweightstyle | no | string | flat | none|user|flat |
In order to correct properly for GTIs, lccorr
needs to know what fraction of events fall on which CCD. (It is assumed that this fraction does not vary over time.) If the spatial distribution of the events is known, these weights can be computed by projecting this distribution against the detector, masked by the selection region; alternatively it may on occasion be simplest just input the CCD weights directly. lccorr
now allows the user several options (with possibly more to come in future). If bkgweightstyle=`none', the task assumes that all the weights equal 1. If bkgweightstyle=`user', the weights are read from parameter bkgweightsnode0 (and, optionally, bkgweightsnode1). Finally, for bkgweightstyle=`flat', the task assumes a uniform spatial distribution of events and projects this distribution against the masked detector CCDs to calculate the weights.
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bkgweightsnode0 | yes | real list | 0 bkgweightsnode0 | |
If bkgweightstyle=`user', this list of values is read by the task. Each value, as a fraction of their sum, should be the fraction of events that are expected to fall on the respective CCD. (If both primary and redundant nodes were used to readout any CCD, the respective weight in the bkgweightsnode0 list should instead be that fraction of bkg events expected to fall on the primary-node half of the CCD. The user should also in this case set withbkgnode1=`yes' and supply the redundant-node weights via bkgweightsnode1.) The user must supply as many values as there are CCDs in the detector: ie 12 for PN and 7 for MOS. The weights should be listed in order of increasing CCD number.
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withbkgnode1 | no | boolean | no | |
The task reads this parameter if bkgweightstyle=`user'. withbkgnode1 instructs the task to look for a list of redundant-node weights in parameter bkgweightsnode1.
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bkgweightsnode1 | yes | real list | 0 bkgweightsnode1 | |
If bkgweightstyle=`user' and withbkgnode1=`yes', this list of values is read by the task. Each value, as a fraction of their sum, should be the fraction of events that are expected to fall on the redundant-node half of the respective CCD. The user must supply as many values as there are CCDs in the detector: ie 12 for PN and 7 for MOS. The weights should be listed in order of increasing CCD number.
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bkgarea | no | real | 1.0 | 0 bkgarea |
If bkgweightstyle=`user', this value is read by the task. The user should provide the area of the extraction region, in units of CCD pixels, not counting dead pixels, chip gaps or other non-live areas of the detector. This parameter is necessary if the background is to be subtracted from the source, in which case the ratio between the areas of the source and background extraction regions must be known.
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subtractbkg | no | boolean | no | |
Whether to subtract the background from the source count rate.
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outset | no | dataset | output_ts.ds | |
Name of the output dataset containing the corrected source and background time series.
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tempset | no | dataset | temp_output_ts.ds | |
Temporary name of output dataset.
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srcweightstyle | no | string | psf | none|user|psf |
In order to correct properly for GTIs, lccorr
needs to know what fraction of events fall on which CCD. (It is assumed that this fraction does not vary over time.) If the spatial distribution of the events is known, these weights can be computed by projecting this distribution against the detector, masked by the selection region; alternatively it may on occasion be simplest just input the CCD weights directly. lccorr
now allows the user several options (with possibly more to come in future). If srcweightstyle=`none', the task assumes that all the weights equal 1. If srcweightstyle=`user', the weights are read from parameter srcweightsnode0 (and, optionally, srcweightsnode1). Finally, for srcweightstyle=`psf', the task assumes that the source is point-like and projects the appropriate Point Spread Function (PSF) against the masked detector CCDs in order to calculate the weights.
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srcweightsnode0 | yes | real list | 0 srcweightsnode0 | |
If srcweightstyle=`user', this list of values is read by the task. Each value, as a fraction of their sum, should be the fraction of events that are expected to fall on the respective CCD. (If both primary and redundant nodes were used to readout any CCD, the respective weight in the srcweightsnode0 list should instead be that fraction of src events expected to fall on the primary-node half of the CCD. The user should also in this case set withsrcnode1=`yes' and supply the redundant-node weights via srcweightsnode1.) The user must supply as many values as there are CCDs in the detector: ie 12 for PN and 7 for MOS. The weights should be listed in order of increasing CCD number.
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withsrcnode1 | no | boolean | no | |
The task reads this parameter if srcweightstyle=`user'. withsrcnode1 instructs the task to look for a list of redundant-node weights in parameter srcweightsnode1.
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srcweightsnode1 | yes | real list | 0 srcweightsnode1 | |
If srcweightstyle=`user' and withsrcnode1=`yes', this list of values is read by the task. Each value, as a fraction of their sum, should be the fraction of events that are expected to fall on the redundant-node half of the respective CCD. The user must supply as many values as there are CCDs in the detector: ie 12 for PN and 7 for MOS. The weights should be listed in order of increasing CCD number.
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srcarea | no | real | 1.0 | 0 srcarea |
If srcweightstyle=`user', this value is read by the task. The user should provide the area of the extraction region, in units of CCD pixels, not counting dead pixels, chip gaps or other non-live areas of the detector. This parameter is necessary if the background is to be subtracted from the source, in which case the ratio between the areas of the source and background extraction regions must be known.
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srcposstyle | no | string | user | user|keyword|dss |
If srcweightstyle=`psf', the task attempts to calculate the fraction of events falling on each CCD by projecting the PSF onto the detector. To do this correctly, the task needs to know the RA and dec of the source. The task provides the user, via the present parameter, with a choice of ways to specify this position. If srcposstyle=`user', the task reads the source position from parameters srcra and srcdec; if `keyword', the task looks for keywords SRC_RA and SRC_DEC (in decimal degrees) in the dataset given in parameter srcposset; if `dss', the task attempts to deduce the centre of the spatial selection regions stored in the Data Sub Space (DSS) of the input source time series.
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srcra | yes | angle | 0.0 | 0 srcra 360 |
RA of the source. Read by the task if srcposstyle=`user'.
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srcdec | yes | angle | 0.0 | -90 srcdec 90 |
Dec of the source. Read by the task if srcposstyle=`user'.
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srcposset | no | dataset | srcposset.ds | |
If srcposstyle=`keyword', the present parameter is read by the task. It contains the name of the dataset containing source position keywords SRC_RA and SRC_DEC. Their values should be in decimal degrees.
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efrac | yes | real | 0.95 | 0 efrac 1 |
The PSF model is truncated to a square area which contains (approximately) this fraction of the total flux. Read by the task if srcweightstyle=`psf'.
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treatvignet | no | boolean | yes | |
Calculate corrections for the mirror vignetting?
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treatfiltertrans | no | boolean | yes | |
Calculate corrections for the filter attenuation?
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treatquantumeff | no | boolean | yes | |
Calculate corrections for quantum efficiency of the ccds?
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treatcosmicrays | no | boolean | yes | |
Calculate corrections for cosmic ray masking?
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treatdeadtime | no | boolean | yes | |
Calculate corrections for frame readout dead time?
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treatgti | no | boolean | yes | |
Calculate corrections for events lost outside GTIs?
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treatalias | no | boolean | no | |
Where the event times are not dithered within the frame duration (the default for PN event lists at time of writing, on 23 Sept 2004), one can generally expect that the binned events will exhibit some form of periodic noise at the difference frequency (plus harmonics) between the time series binning frequency and the CCD frame readout frequency. If treatalias is set `yes', lccorr
will attempt to correct this effect. At present it is recommended to leave this parameter at default.
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applycorrections | no | boolean | yes | |
Apply the exposure corrections to source and background count rates?
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Parameter | Mand | Type | Default | Constraints |