COMPOSITE OF OBSERVED SPECTRUM OF NML CYGNI Assembled 03-12-96 by Martin Cohen (see note below) N.B. This is a "special" product assembled without benefit of photometry by a newly-developed end-to-end procedure. Alhough photometry does exist in Gezari et al. (the "CIO"), it is essentially untraceable: the exact passbands used are not characterized; zero points are usually not available; traceability to specific "standard stars" is generally not possible (blackbody assumptions underpin most of these magnitudes in the literature). However, what I have done is to tie the complete spectrum to Glaccum's KAO long wavelength spectroscopy, absolutely calibrated on Mars (good to +/-2.5%), and secured with a large aperture. Glaccum spectra usually match well to other composites when joining to LRS or ground-based 20 micron spectra. Note that there are some real features near 34 micron (and perhaps also near 28 micron) in the Glaccum data, also a potential silicate absorption at 10 micron in the UKIRT spectrum. Although there exists an unpublished KAO spectrum from 1.3--4.0 micron, I can find nothing in the KAO archives by way of a bridging spectrum from 5--8 micron. Thus, this composite starts near 7.5 micron and is continuous to 66 micron. As such it is probably a useful tertiary (secondary?) calibrator for SWS, particularly in bands 3 and 4, and may furnish a possible cross calibrator for SWS with LWS, and can also be observed by PHT. But CAVEAT EMPTOR! this cannot be regarded as a "high quality" absolute calibrator although its low-resolution shape is likely to be valid. There is little information to seek variability of this very bright source: a single HCON exists in IRAS so the source does not appear in the PSC/FSS. Having issued all these warnings, however, I have run standard characterized passbands over the finished product and find plausible values of magnitudes near 10/20 um as follows (cf. the CIO): [8.7] = 5.0; N = -5.4; [11.7] = -5.8; [20] =-7.0. =============================================================================== Spectral fragments and portions of these actually used in observed spectrum (``used" may include combination with other data where overlaps occur) Fragment Reference Total range Start and stop Average resolving (um) wavelengths (um) power NIR 1 1.30- 4.00 mot used 50 8-13 2 7.50-13.30 7.50-13.30 55 LRS 3 7.67-22.70 11.30-22.70 30 LONG 4 19.92-35.03 19.92-35.03 30: VLONG 5 35.19-65.80 35.19-65.80 30: References: 1. Strecker, unpublished KAO archives, NASA-Ames (unused here because there is no continuity with the other fragments). 2. UKIRT CGS3 data of October 7, 1992 [NML Cyg/beta Peg], both taken at airmass 1.17 by Sylvester & Skinner. 3. LRS raw data extracted from the old Groningen "LRSVAX" archive maintained at NASA-Ames and recalibrated correctly. 4,5. From Glaccum (1990): taken on the KAO flight of July 7, 1986 with the Goddard 24 channel He-3 bolometer spectrometer in two grating settings, and calibrated against Mars. INFORMATION ON SPLICES AND BIASES INCURRED Process Factor determined Bias (%) LRS blue/red bias -- 0.06 LRS splice to 813 1.651 0.55 LONG splice to merged 813/LRS 1.000 0.15 V.LONG splice to LONG spectrum 1.000 0.50 ==================================================== Notes: 1. Composite spectra are NOT tabulated at equal intervals of the wavelength, but rather at the wavelengths of the original measurements. 2. In most cases "total uncertainty" is the error term most appropriate to use. It is the standard deviation of the spectral irradiance and includes the local and global biases. Local and global biases are given as a percent of the irradiance. The global bias does not contribute error to flux ratios or color measurements, and may, in those cases, be removed (in the rss sense) from the total error. ==================================================== ________Uncertainties________ Wavelength Irradiance Total Local Bias Global Bias (microns) (w/cm2/um)(w/cm2/um) (%) (%) .7497E+01 .2396E-13 .1150E-14 .0000E+00 .2500E+01 .7583E+01 .2599E-13 .9740E-15 .0000E+00 .2500E+01 .7685E+01 .2445E-13 .7015E-15 .0000E+00 .2500E+01 .7770E+01 .2261E-13 .6561E-15 .0000E+00 .2500E+01 .7872E+01 .2352E-13 .6677E-15 .0000E+00 .2500E+01 .7958E+01 .2300E-13 .6863E-15 .0000E+00 .2500E+01 .8059E+01 .2226E-13 .6291E-15 .0000E+00 .2500E+01 .8145E+01 .2169E-13 .5747E-15 .0000E+00 .2500E+01 .8246E+01 .2160E-13 .5638E-15 .0000E+00 .2500E+01 .8332E+01 .2152E-13 .5716E-15 .0000E+00 .2500E+01 .8433E+01 .2139E-13 .5631E-15 .0000E+00 .2500E+01 .8519E+01 .2128E-13 .5718E-15 .0000E+00 .2500E+01 .8620E+01 .2073E-13 .5358E-15 .0000E+00 .2500E+01 .8706E+01 .2003E-13 .5261E-15 .0000E+00 .2500E+01 .8807E+01 .1959E-13 .5070E-15 .0000E+00 .2500E+01 .8892E+01 .1896E-13 .4964E-15 .0000E+00 .2500E+01 .8993E+01 .1768E-13 .4564E-15 .0000E+00 .2500E+01 .9079E+01 .1648E-13 .4314E-15 .0000E+00 .2500E+01 .9180E+01 .1555E-13 .4013E-15 .0000E+00 .2500E+01 .9265E+01 .1472E-13 .3869E-15 .0000E+00 .2500E+01 .9366E+01 .1343E-13 .3505E-15 .0000E+00 .2500E+01 .9451E+01 .1339E-13 .3512E-15 .0000E+00 .2500E+01 .9552E+01 .1308E-13 .3397E-15 .0000E+00 .2500E+01 .9637E+01 .1272E-13 .3354E-15 .0000E+00 .2500E+01 .9738E+01 .1267E-13 .3294E-15 .0000E+00 .2500E+01 .9823E+01 .1232E-13 .3262E-15 .0000E+00 .2500E+01 .9923E+01 .1239E-13 .3218E-15 .0000E+00 .2500E+01 .1001E+02 .1222E-13 .3211E-15 .0000E+00 .2500E+01 .1011E+02 .1219E-13 .3157E-15 .0000E+00 .2500E+01 .1019E+02 .1217E-13 .3186E-15 .0000E+00 .2500E+01 .1029E+02 .1203E-13 .3111E-15 .0000E+00 .2500E+01 .1038E+02 .1207E-13 .3156E-15 .0000E+00 .2500E+01 .1048E+02 .1221E-13 .3158E-15 .0000E+00 .2500E+01 .1056E+02 .1229E-13 .3214E-15 .0000E+00 .2500E+01 .1066E+02 .1246E-13 .3223E-15 .0000E+00 .2500E+01 .1075E+02 .1251E-13 .3275E-15 .0000E+00 .2500E+01 .1085E+02 .1282E-13 .3326E-15 .0000E+00 .2500E+01 .1093E+02 .1304E-13 .3441E-15 .0000E+00 .2500E+01 .1103E+02 .1315E-13 .3392E-15 .0000E+00 .2500E+01 .1112E+02 .1327E-13 .3455E-15 .0000E+00 .2500E+01 .1122E+02 .1321E-13 .3418E-15 .0000E+00 .2500E+01 .1130E+02 .1332E-13 .3492E-15 .0000E+00 .2500E+01 .1140E+02 .1371E-13 .3560E-15 .0000E+00 .2500E+01 .1148E+02 .1369E-13 .3614E-15 .0000E+00 .2500E+01 .1158E+02 .1340E-13 .3486E-15 .0000E+00 .2500E+01 .1167E+02 .1356E-13 .3624E-15 .0000E+00 .2500E+01 .1177E+02 .1310E-13 .3449E-15 .0000E+00 .2500E+01 .1185E+02 .1296E-13 .3425E-15 .0000E+00 .2500E+01 .1195E+02 .1249E-13 .3269E-15 .0000E+00 .2500E+01 .1203E+02 .1220E-13 .3220E-15 .0000E+00 .2500E+01 .1213E+02 .1184E-13 .3105E-15 .0000E+00 .2500E+01 .1222E+02 .1162E-13 .3079E-15 .0000E+00 .2500E+01 .1231E+02 .1147E-13 .2986E-15 .0000E+00 .2500E+01 .1240E+02 .1107E-13 .2937E-15 .0000E+00 .2500E+01 .1259E+02 .1095E-13 .2943E-15 .5532E+00 .2500E+01 .1270E+02 .1080E-13 .2920E-15 .5532E+00 .2500E+01 .1279E+02 .1048E-13 .2817E-15 .5532E+00 .2500E+01 .1310E+02 .1028E-13 .2864E-15 .5532E+00 .2500E+01 .1341E+02 .9731E-14 .2997E-15 .5532E+00 .2500E+01 .1372E+02 .9473E-14 .2951E-15 .5532E+00 .2500E+01 .1403E+02 .8895E-14 .2800E-15 .5532E+00 .2500E+01 .1432E+02 .8468E-14 .2683E-15 .5532E+00 .2500E+01 .1462E+02 .8061E-14 .2586E-15 .5532E+00 .2500E+01 .1490E+02 .7856E-14 .2540E-15 .5532E+00 .2500E+01 .1518E+02 .7591E-14 .2473E-15 .5532E+00 .2500E+01 .1546E+02 .7648E-14 .2512E-15 .5532E+00 .2500E+01 .1573E+02 .7265E-14 .2387E-15 .5532E+00 .2500E+01 .1599E+02 .7018E-14 .2312E-15 .5532E+00 .2500E+01 .1625E+02 .6929E-14 .2288E-15 .5532E+00 .2500E+01 .1651E+02 .6807E-14 .1931E-15 .5532E+00 .2500E+01 .1677E+02 .6482E-14 .1835E-15 .5532E+00 .2500E+01 .1701E+02 .6380E-14 .1805E-15 .5532E+00 .2500E+01 .1726E+02 .6148E-14 .1738E-15 .5532E+00 .2500E+01 .1750E+02 .6126E-14 .1731E-15 .5532E+00 .2500E+01 .1774E+02 .5901E-14 .1668E-15 .5532E+00 .2500E+01 .1798E+02 .5810E-14 .1644E-15 .5532E+00 .2500E+01 .1821E+02 .5596E-14 .1583E-15 .5532E+00 .2500E+01 .1844E+02 .5509E-14 .1559E-15 .5532E+00 .2500E+01 .1867E+02 .5360E-14 .1517E-15 .5532E+00 .2500E+01 .1889E+02 .5171E-14 .1465E-15 .5532E+00 .2500E+01 .1911E+02 .5165E-14 .1464E-15 .5532E+00 .2500E+01 .1933E+02 .5140E-14 .1459E-15 .5532E+00 .2500E+01 .1955E+02 .4879E-14 .1386E-15 .5532E+00 .2500E+01 .1992E+02 .4698E-14 .1218E-15 .5725E+00 .2500E+01 .2069E+02 .4456E-14 .1150E-15 .5725E+00 .2500E+01 .2164E+02 .3801E-14 .9902E-16 .5725E+00 .2500E+01 .2245E+02 .3600E-14 .9253E-16 .5725E+00 .2500E+01 .2349E+02 .3171E-14 .8232E-16 .5725E+00 .2500E+01 .2441E+02 .2811E-14 .7284E-16 .5725E+00 .2500E+01 .2527E+02 .2500E-14 .6585E-16 .5725E+00 .2500E+01 .2622E+02 .2268E-14 .5936E-16 .5725E+00 .2500E+01 .2716E+02 .2054E-14 .5427E-16 .5725E+00 .2500E+01 .2807E+02 .1843E-14 .4890E-16 .5725E+00 .2500E+01 .2898E+02 .1691E-14 .4385E-16 .5725E+00 .2500E+01 .2987E+02 .1484E-14 .3938E-16 .5725E+00 .2500E+01 .3067E+02 .1305E-14 .3427E-16 .5725E+00 .2500E+01 .3166E+02 .1146E-14 .3041E-16 .5725E+00 .2500E+01 .3246E+02 .1057E-14 .2761E-16 .5725E+00 .2500E+01 .3339E+02 .9821E-15 .2933E-16 .5725E+00 .2500E+01 .3418E+02 .8787E-15 .2355E-16 .5725E+00 .2500E+01 .3503E+02 .7679E-15 .2290E-16 .5725E+00 .2500E+01 .3519E+02 .7367E-15 .2164E-16 .7071E+00 .2500E+01 .3697E+02 .5852E-15 .1836E-16 .7071E+00 .2500E+01 .3844E+02 .5045E-15 .1823E-16 .7071E+00 .2500E+01 .4024E+02 .4024E-15 .1060E-16 .7071E+00 .2500E+01 .4203E+02 .3463E-15 .9315E-17 .7071E+00 .2500E+01 .4367E+02 .3083E-15 .9808E-17 .7071E+00 .2500E+01 .4552E+02 .2595E-15 .7509E-17 .7071E+00 .2500E+01 .4708E+02 .2160E-15 .6233E-17 .7071E+00 .2500E+01 .4857E+02 .1934E-15 .5479E-17 .7071E+00 .2500E+01 .5032E+02 .1507E-15 .5643E-17 .7071E+00 .2500E+01 .5188E+02 .1445E-15 .4545E-17 .7071E+00 .2500E+01 .5368E+02 .1217E-15 .3692E-17 .7071E+00 .2500E+01 .5513E+02 .1150E-15 .3386E-17 .7071E+00 .2500E+01 .5687E+02 .8983E-16 .5013E-17 .7071E+00 .2500E+01 .5835E+02 .8521E-16 .5951E-17 .7071E+00 .2500E+01 .6009E+02 .8065E-16 .3356E-17 .7071E+00 .2500E+01 .6145E+02 .7327E-16 .2627E-17 .7071E+00 .2500E+01 .6294E+02 .6877E-16 .2086E-17 .7071E+00 .2500E+01 .6451E+02 .6463E-16 .3011E-17 .7071E+00 .2500E+01 .6580E+02 .6567E-16 .6337E-17 .7071E+00 .2500E+01