Q: I am updating my scripts for OSA7, and running the same command as I did under OSA6. However, the output in jmx1_obs_res.fits that I get now seems to have extra energy bands, namely 3-7, 7-11, 11-20 keV as well as the energy bands that I asked for - why is this ?
A: The reason is that j_ima_iros does use these 3 extra bands for the source search, whatever the user's requested bands are. So you get these fluxes as extra information - always in the 3 first columns of jmxi_res_srcl.fits and jmxi_obs_res.fits. Anyway, the fluxes reported in jmxi_srcl/obs_res.fits are not really reliable yet and one should rather use mosaic_spec to extract the fluxes from the images.
Q: Is there still the 7 source limit in OSA7 that there was in OSA6, or can I expand the input catalogue to contain other sources now ?
A: There is no longer a limit on the number of sources in your input catalogue as long as the sources are flagged with FLAG=1 and not with 3, which is used to force the fit of the given position by j_ima_iros (not recommended). But you must be aware that the more sources you have the longer it takes to run the analysis.
Q: Why do I get lightcurves and/or spectra from sources close to the positions in my user catalogue but not exactly from those positions as was the case in the previous OSA releases?
A: The positions put in the user_cat are not copied in RA_OBJ and DEC_OBJ, but in 2 extra columns: RA_CAT and DEC_CAT. RA_OBJ and DEC_OBJ are the found position by j_ima_iros. The problem is that it is still RA_OBJ and DEC_OBJ that are used by the source extraction S/W to produce light curves and spectra, so you may not get what you expect here... The solution for the moment is to copy RA_CAT and DEC_CAT into RA_OBJ and DEC_OBJ before extracting light curves and spectra.
Q: There was some confusion a while ago about the settings to use for mosaic_spec in particular the value of psf when extracting fluxes from the mosaic image
A: I attach below my "recipe" to use mosaic_spec. Usage of mosaic_spec. For the Crab (widthmode optional): Flux read in j_ima_iros intensity map mosaic_spec Crab422_85_ima.fits "spec.fits(JMX1-PHA1-SPE.tpl)" \ ra=83.6332 dec=22.0145 posmode=0 EXTNAME=JMX1-SKY.-IMA \ Intensity=RECONSTRUCTED psf=2. widthmode=0 Flux read in j_ima_mosaic intensity map mosaic_spec jmx1_mosa_ima.fits.gz "spec.fits(JMX1-PHA1-SPE.tpl)" \ ra=83.6332 dec=22.0145 posmode=0 EXTNAME=JMX1-MOSA-IMA \ Intensity=RECONSTRUCTED psf=2. widthmode=0 For strong sources: posmode=0 and widthmode=0 For weak sources: posmode=-1 (TBC) Results: 3-10 keV: 1 cnt/s = 10 mCrab 10-25keV: 1 cnt/s = 30 mCrab These results have been updated for the later mission sensitivity in 2022
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