971215n Processing notes: ----------------- CALMON namelist was overridden with minnfinblk1 = 4 (to pass the photometric interval at night's end) Scans failing processing: NONE Scans failing ACT reconstruction: NONE Check of darks/flats: Flats were taken and accepted in all bands. Plot of frame medians looks normal, and diagnostic images also look normal (except that the quadrant boundaries at Ks-band are different from the canonical at a low level). Darks were also taken and accepted at all bands, and the plot of frame medians looks good. The nightly/scan-by-scan overview pages are at: http://irsatest.ipac.caltech.edu:8001/data/2mass/lgos/qa971215n General: -------- Observers reported cirrus up through 01 UT with clearing conditions afterward. Cirrus began approaching again around 05 UT and was definitely moving overhead by 06 UT. By 07 UT, cirrus was no longer obvious overhead but the horizons were riddled with the stuff. Observations halted at 09:10 UT because of clouds. Replanned night at 10:30 UT after west appeared to clear. Clear skies reported thereafter. H and Ks backgrounds began rising at the end of scan 062. Fast rises also seen in scan 064. Rapid background variations seen in scan 081. Bright stars/meteors/etc. in need of MAPCOR artifact cleanup: Scan Coadd Notes ---- ----- ----- 009 220 01h58m03.79s +31d08m04.0s AA Trianguli, M3, V=7.1 036 79 meteor 042 232 02h09m32.66s +34d59m15.8s beta Trianguli, A5 III, V=3.00 069 256 meteor 070 103 02h18m36.44s +32d07m37.8s BD+31 395, M5, V=8.50 092 220 meteor 123 32 M105 is sufficiently bright to cause its own persistence; there are two persistence artifacts found by the source extractor, but only one is properly flagged 125 173 meteor 136 68 meteor 141 79 10h53m37.43s +13d42m54.8s W Leonis, M5.5e, V=8.90 141 138 meteor Other sources of interest: (Note that the M105 group -- M105, NCG 3384, and NGC 3389 -- might make a very nice mosaic.) Scan Coadd Notes ---- ----- ----- 008 150 merging elliptical galaxies NGC 750 and NGC 751; the composite looks like a peanut with a Don King hairdo 013 197 elliptical galaxy NGC 777 066 126 little galaxy duo IC 1784 and IC 1785 069 162 edge-on spiral IC 1789 115 9 big galaxy M96 just off south edge of scan 115 91 very nice army spiral NGC 3367 123 32 bright elliptical galaxy M105 123 91-103 sizable elliptical galaxy NGC 3377 124 232 bright elliptical galaxy NGC 3384 124 244 (M105 on edge of scan) 125 32 spiral galaxy NGC 3389 127 197 tight galaxy cluster 136 185 funky little S0 (?) galaxy NGC 3419 136 197-209 another elliptical (?) NGC 3412 140 21 low surface brightness spiral NGC 3443 141 220 low surface brightness spiral NGC 3447a Photometricity: --------------- New calibration strategy. CALMON passes first seven cal sets without override. Eighth set fails due to high dispersions, and the implied zero-point for this set is ~0.2-0.3 mag different from earlier in the night when the zero-point appeared very stable. After restart of observations at 10:30 UT, the last four cal sets were also passed after minnfinblk1 was set to 4 instead of 5. This last photometric block gets a downgrade to 0.9 (sqrt[4/5]). Repeatability in the overlaps is given by http://irsatest.ipac.caltech.edu:8001/data/2mass/lgos/qa971215n/ut971215n.ps http://irsatest.ipac.caltech.edu:8001/data/2mass/lgos/qa971215n/cum971215n.ps The first four sci blocks have a peak-to-peak scatter below 0.05 mag. The fifth and sixth blocks show increased scatter close enough to 0.05 mag to warrant a downgrade to a quality factor of 0.7. (Operators also mentioned that cirrus was definitely moving overhead during these scans, so the downgrade is justified.) The seventh block has a scatter of 0.07 mag, but this block has already been deemed non-photometric. After the break in observations, the eighth block shows a scatter at Ks-band of ~0.055 mag, which incurs a penalty of 0.7 in photometric downgrade. The last two blocks are under 0.05 mag in all bands. In summary, Scans Phot. quality factor ------- -------------------- 007-014 1.0 021-028 1.0 035-042 1.0 049-056 1.0 063-070 0.7 077-083 0.7 090-097 0.0 110-116 0.6 (0.9*0.7) 123-129 0.9 136-141 0.9 Sensitivity: ------------ See plot at http://irsatest.ipac.caltech.edu:8001/data/2mass/lgos/qa971215n/q971215n.bg.see.ps Sensitivities are within tolerance for all sci scans (though a few of the cal scans have decreased sensitivities). In summary, Scans Sensitiv. quality factor ------- ------------------------ 007-014 1.0 021-028 1.0 035-042 1.0 049-056 1.0 063-070 1.0 077-083 1.0 090-097 1.0 110-116 1.0 123-129 1.0 136-141 1.0 Background/Jump Counters: ------------------------- Backgrounds show moderate airglow in scans 007-014, 049, 083 (reaches 300 DN variation at H), and 110-111. Sharp J jumps and drops are seen in the backgrounds for the following scans: 026 (drop of ~30 DN for frames ~20-30), 027 (drop of ~15 DN for frames ~5-80), 035 (jump of ~15 DN at frame ~185), 051 (drop of ~35 DN for frames ~18-22), 065 (drop of ~35 DN at frame ~55), 067 (drop of ~35 DN at frame ~60 plus jumps throughout frames 70-120), 069 (jump of ~25 DN at frame ~155), and 127 (drop of ~10 DN at intermittent intervals). I've checked the J-band images for all of these, and none of the jumps/drops are imprinted into the coadds. Sharp rises in the backgrounds (H rises by 650 DN, Ks by 200) are seen in scan 063. The variations are correlated in all three bands, and the coadds also indicate that this is just a very healthy case of OH airglow. There are also some three-band correlated variations where the J-band shows the most significant variations. These are found in scans 092 (J varies by 140 DN) and 093-095 (J varies by 100 DN). These scans have already been downgraded to quality=0 because of clouds in the cal set following them. Although most clouds create the strongest variations at Ks-band, light cirrus strongly illuminated by moonlight is the most likely explanation for these J-bright fluctuations. (Note that the moon was within a day of full on this night.) These coadds show structure in the backgrounds, and it is indeed most noticeable at J-band. Jump Counters: Scan J H K Counts Notes ---- ------------ ----- 094 14 4 1 cirrus (scan already has phot. factor = 0.0) 110 0 4 0 OH airglow Untracked Seeing/Second Image Moment Ratios: -------------------------------------------- Untracked seeing: All OK Bad 2nd image moment ratios: (max quality score = 1) Scans ----- 007-012 Quality Recommendation: ----------------------- Sci scans: (optimal dither used; max score = 10) Scans Grade Notes ------- ----- ----- 007-012 1 bad 2nd image moment 013-014 10 10*1.0*1.0 021-028 10 10*1.0*1.0 035-042 10 10*1.0*1.0 049-056 10 10*1.0*1.0 063-070 7 10*0.7*1.0 077-083 7 10*0.7*1.0 090-097 0 non-photometric 110-116 6 10*0.6*1.0 123-129 9 10*0.9*1.0 136-141 9 10*0.9*1.0 Cal scans: (non-photometric = 0, photometric = 10) Scans Grade Notes ------- ----- ----- 001-006 10 015-020 10 029-034 10 043-048 10 057-062 10 071-076 10 084-089 10 098-103 0 104-109 10 117-122 10 130-135 10 142-147 10 Special Notes: -------------- None. SCANSCI Template: Version 1.4, Last Updated 9/28/98 by Robert Hurt