The ftp directory contains parts of two observations of the Crab supernova remnant performed by the BeppoSAX instruments during the Science Verification Phase. Detailed information on BeppoSAX data reduction and analysis software is available at: /bepposax/software/ FOT directory ------------- Data in the "fot" directory are in original FOT format (see the page /bepposax/software/fot.html for more information). They are divided in 4 subdirectories: op_839_fot_624_saxdas PDS & HPGSPC SAXDAS naming convention op_839_fot_624_xas PDS & HPGSPC XAS naming convention op_886_fot_491_saxdas LECS & MECS SAXDAS naming convention op_886_fot_491_xas LECS & MECS XAS naming convention XAS users should copy the files with the XAS naming convention. SAXDAS users should copy the files with the SAXDAS naming convention. For the Wide Field Camera (WFC) instrument, two observations are supplied: wfc_op_917w12_fot.tar.gz op_917/wfc1, /wfc2 (CRAB + Galactic Centre) wfc_op_919_test_dat.readme op_919/wfc1, helpfile and data in *.dat files wfc_op_919_test_dat.tar.gz For details about the WFC analysis software see SAX/SDC Web pages on WFC software at /bepposax/software/wfc_general_index.html FITS directory -------------- The "fits" directory contains SAXDAS linearized and screened event files (*lev*flt.fits files). These are equivalent to ROSAT or ASCA linearized event files and can be directly analyzed with popular X-ray analysis packages. The "fits" directory also contains SAXDAS fits housekeeping files, containing housekeeping, LECS ratemeters, attitude and auxiliary quantities data (*hkg* files) and MECS ratemeters files (*eng* files) Data contained in these files can be plotted and used to form new GTI using the SAXDAS program hkplot (see the page /bepposax/software/saxdas/hkplot_walk.html for more information). Please note that the abrupt changes in the LECS Crab countrate are caused by source obscuration by the window support strongback grid. The grid consists of 4 by 4 arcminute squares, and can cause extra, energy dependent, obscuration of up to ~30% for a point source. The effect of this obscuration is accounted for in the LECS response matrix generation program (LEMAT). For the WFCs, a tar is available containing the corresponding fits files for op_917/wfc1, /wfc2 (wfc_op_917w12_fits.tar.gz) and op_919/w1 (wfc_op_919_test_fits.tar.gz). The tarfile for op_917 contains *0000*.gti good time interval files, in which the earth occultation periods (with earth rim angle > 28 from centre of Field of view) are already excluded. For an explanation see the SAX/SDC Web page with the walk-through WFC basic data analysis at /bepposax/software/wfc/wfc_walk.html Problems, reports or any question can be addressed to helpdesk@sax.sdc.asi.it