LRIS notes. Apr19 2001. Data reduction strategy bias - use lrisbias. flats - combine internal flats and normalise (cant use median because of discontinuity in middle) could try Greg's 2-amp correction thing see alg/scripts trim,flatfield - use lccdproc sky subtract 2D frames (4th order legendre?) make fringe map (median multiple frames,median smoothed on scale of 5x5) subtract fringe map from individual frames shift individual frames combine shifted frames ----------------------------------------------------------- JS Bach science: 1034, 1035 flats 1036,1037 used lccdproc to do overscan, timming & zero correction combined flats using imcombine. normalised using normflat used lccdproc to do flat correction. subtracted background from science frames > r1034s,r1035s made a fringe map by averaging these (with minmax, high=1, low=0) subtracted fringe map from the sky subtracted science images > r1034sf,r1035sf IMH jun01: extracted spectra from the 2d files. Lost trace in the blue. Cant see evidence for z=0.765 ------------------------------------------------------ Gresse science 1038, 1039, 1040 flats 1041, 1042 made fringe map gresse_fr This time subtract that from the non-sky subtracted images > r1038f,r1039f,r1040f extracted the objects > f1038fx etc combined calibrated 1d spectra > gresse_fc z=0.671 Ca H&K, possibly OII IMH Jun01 : SN features look OK if you subtract galaxy template ------ sibelius science 1044, 1045, 1047, 1048 flat 1046, 1049 cant see the object well enough to set the apertures. Try adding the 2d frames. Or use fixed relative aperture = 25:32.4 made flat sib_flat flattened science data. Sky subtracted science data fringe frame - two frames overlap (1044,1045) 1044 - use 1047s,1048s > sib_fr1 1045 - use 1047s,1048s "" 1047 - use 1044s,1048s sib_fr2 1048 - use 1045s,1047s sib_fr3 subtracted fringe frames from science frames - objects get weaker Need a scaling? Need slit function correction try registering the frames r1044sf 482.95 -32.98 r1045sf 515.93 0.0 r1047sf 610.69 94.76 r1048sf 401.55 -114.38 combined 2d frame sib_comb extraction from that sib_combc looks flat ----------------------------------- gershwin S37 science 1050,1051,1053 flat 1052,1054 shifts r1050 672.86 24.67 r1051 648.19 0.00 ) too close together. r1053 644.88 -3.31 ) try pairs imarith r1050 - r1051 r1050sub imarith r1051 - r1050 r1051sub imarith r1053 - r1050 r1053sub shifted & combined to make gersh_sub_comb extracted > gersh_sub_combx flat spectrum. IMH may01 : did flux calibration using r1025sens and mkoextinct.dat ------------------ bizet = 005 science 1055, 1056 flats 1057, 1058 shifts 1055 805.672 1056 854.823 49.15 subtracted the images, shifted & averaged > biz_sub_comb extracted spectrum from that > biz_sub_combc No lines! --------- Holst science 1059, 1060, l063(wrong place), l064 flats l061, l062 offsets make objects overlap again. have to use pairs again 1059 - use 1064 1060 - cant use anything 1061 - use 1059 just extract without fringe correction for now. I think this is z=0.37 based on SN spectrum No galaxy lines obvious. Try blue side