BeppoSAX e-mail news n. 8
18 April 2000 Dear BeppoSAX user, this is the eighth BeppoSAX "e-mail news" message and covers the following topics: 1. Release of SAXDAS 2.1.1 software 2. Release of improved calibrations 1. Release of SAXDAS 2.1.1 software ------------------------------------ SAXDAS 2.1.1 has to be installed under ftools5.0 Modifications with respect to SAXDAS 2.0: - foting is Y2K compliant. HPGSPC DIR002, DIR003 and DIR004 modes are implemented. PDS duplicate packets are disregarded. - pdproducts now generate a merged background light curve file (_bck.lc) - Full support for HPGSPC. A new background strategy is implemented in hpproducts. Dark Earth data are used instead of data from off-source regions. Therefore the HPGSPC collimator is kept on source for the whole observation, doubling the on-source exposure time. - the program LEMAT (to generate LECS .arf and .rmf files), including the latest ray-tracing code and the latest LECS calibrations, is included in the release. - Bug fixed in EVELIN. This resulted in no spatial gain correction in LECS linearized event files (maybe relevant for sources at off-axis angles > 8 arcmin, on axis source are basically not affected). - Several minor bugs have been corrected. The SAXDAS 2.1.1 software is available from the SDC anonymous ftp service: ftp www.sdc.asi.it Name : anonymous cd pub/sax/software/saxdas dir Binary version of SAXDAS 2.1.1 are available for the following platforms: OSF4.0 Solaris 2.7 Linux Red Hat 6.1 The binary release is reachable in the directory cd pub/sax/software/saxdas/binaries dir 2. Release of improved calibrations ----------------------------------- - The LECS response is now calibrated up to 10 keV. Redistribution matrix and effective area can be generated using the program LEMAT, included in the SAXDAS 2.1.1. distribution. They can also be retrieved from the SDC anonymous ftp. The LECS response is now (slightly) dependent on the source count rate. This is due to the modelling of double events (events which occur very soon after each other are detected at their sum-energy). Double event modelling has (almost) no measurable effect below ~ 30 cts/sec while only above ~60 cts/sec the correction is noticable. So for the vast majority of the sources this effect is completely unimportant, only for *very* bright sources (Crab, Cyg X-2) this effect is important and a response should be generated appropiate for the count rate. In summary: LECS count rate less then 30 cts/sec: use standard rmf LECS count rate higher than 60 cts/sec: for optimal modeling one should use the matrix generated for this count rate LECS count rate between 30 and 60: the effects is probably not important, but it depends on the shape of the spectrum (and the signal to noise (i.e. EXPOSURE)), so if you want to be safe use the appropriate matrix The files in the SDC anonymous ftp were generated for a source with a count rate of 0.5 cts/sec, - A new HPGSPC effective area file is available (HPGSPC_jul99.arf). This MUST be used for observations performed AFTER JULY 1999. For observations performed before July 1999, the old HPGSPC_oct98.arf file MUST be used. The new LECS and HPGSPC .arf and .rmf response files are available from the SDC anonymous ftp in the /pub/sax/cal/responses/99_12 directory. MECS and PDS response files have not been modified and can be retrieved from the /pub/sax/cal/responses/98_11 directory. - New LECS background files are now available. The total sky and non X-ray backgroud (dark Earth) exposures are now of 1.0 and 1.2 Msec respectively. Background event files and .pha files are available in the /pub/sax/cal/bgd/99_12 and /pub/sax/cal/bgd/98_11 directories. *********************************************************************** The BeppoSAX software, calibration and documentation is also available from the mirror of the SDC anonymous ftp service based at HEASARC: ftp legacy.gsfc.nasa.gov Name : anonymous cd sax/software/saxdas SAXDAS 2.1.1 cd sax/cal/responses .arf and .rmf response files cd sax/cal/bgd Background event and .pha files *********************************************************************** Please consult the README files before retriving the new calibrations. *********************************************************************** Fabrizio Fiore, Francesca Tamburelli & Paolo Giommi BeppoSAX Science Data Center ------------------BeppoSAX SDC useful addresses and numbers---------------- WWW home page http://www.sdc.asi.it/ anonymous ftp www.sdc.asi.it phone +39 06 40796307 (M.E. Pennisi, SDC secretary) fax +39 06 40793855, +39 06 40796291 e-mail helpdesk@sax.sdc.asi.it p-mail address BeppoSAX Science Data Center ASI c/o Nuova Telespazio via Corcolle 19 00131 Roma Italy how to reach us http://www.sdc.asi.it/howreach.html ---------------------------------------------------------------------------