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Helpdesk

Questions about Swift? Try our guide to Swift or the guide to data processing and analysis. If these don't solve your problem, please feel free to e-mail us at swifthelp@le.ac.uk.

List of acronyms and abbreviations

We are located in the Department of Physics & Astronomy , at the University of Leicester (directions).

Producing a quality map, defining hot pixels and apply mask-weighting

For the following scripts, expressions included within square brackets [ ] are default values, so do not necessarily need to be included. However, if, for example, outunits is changed, this new value will be remembered, so it is better to include all the commands.

By default, clobber=no, so include clobber=yes on the command line to overwrite files if required. 

>batbinevt [weighted=no outunits=counts]
>Input event file name: sw003774870000bevshsp_uf.evt
>Output file name: grb.dpi
>Make light-curve or spectrum: dpi
>Histogram time bin size: 0
>Time binning algorithm: u
>Energy bin list: -

If the user is processing the BAT data from scratch, the input file will be the *evt file in the [obsid]/bat/event directory (sw00374210000bevshsp_uf.evt in the example above).

DPI stands for Detector Plane Image.

A time bin size of 0 was used because this is not a light-curve. The time binning algorithm 'u' stands for uniform. Alternatives are snr for constant signal to noise and gti, where the good time intervals are used.

Setting the energy bin list to '-' means that 1 energy bin will be used for the entire spectral range. 

>bathotpix detmask=sw00377487000bdecb.hk.gz
>Input detector plane image: grb.dpi
>Output image mask: grb.mask

The input files, e.g. the detector mask (sw00377487000bdecb.hk.gz in this example), can be used while still gzipped. The *bdecb.hk file will be located in the [obsid]/bat/hk directory. 

>batmaskwtevt detmask=grb.mask
>Input event file name: sw003774870000bevshsp_uf.evt
>Input attitude file name: sw00377487000sat.fits.gz
>Input RA: 203.1487
>Input Dec: 34.0884

The *sat.fits.gz file will be located in the [obsid]/auxil directory.

The RA and Dec can be obtained from the header of the sw00377487000bevshsp_uf.evt file, under the heading RA_OBJ and DEC_OBJ. They must be given in decimal degrees.

This does not produce a new file, but rather adds (or alters) a column called MASK_WEIGHT in the event file.

Index