IRAS Small-Scale Structure Catalog FormatThe Catalog is contained in one file ordered by right ascension and by declination in case of conflict. For each source, data are shown only for those bands where detections have been found and have survived processing through "weeks confirmation". No upper limits are given where no detections were found; none are given where detections were dropped because of confusion ("cluster analysis"). Absence of data from this Catalog at a given position in a given band does not imply absence of emission, but simply lack of information (see Chapter VI of the reference for a discussion of completeness). On the other hand, flags NEARPS, SES1 and HD, which depend only on position in the sky, are always estimated for all four bands, at the mean position of each source. In general, the data for each source are organized in three 80-byte records followed by a variable number of association records; Table 1 shows details of the organization. The first two records contain basic parameters and warning flags referring to the band-merged source, whereas the third record is made up of four 20-byte components containing position and quality flags for each of the bands. When present, the 12 micron data are inserted into the first 20 bytes of the record; the 25, 60, and 100 micron data go into the second, third, and last block of 20 bytes in the record, respectively. Quarters corresponding to bands absent from the source are filled with blanks. The fourth and subsequent records contain data on positional associations between the Catalog source and objects in a variety of astronomical catalogs listed in the description of the format of the Point Source Catalog. Each record holds data on two associations, in two 40-byte blocks. All data entries for each source are described below in their order of appearance in Table 1. As distributed, the catalog is divided into two files. The first is a 240-byte record file containing the 16,740 sources. The second is a 58-byte record file containing the 5,178 associations. The file formats are described below in Tables 1 and 2. Table 1. Format of the Small-Scale Structure Sources File Start Byte Name Description Units Format 1 NAME IRAS source name --- 10A1 11 BMFLG Number of bands in source --- A1 [1] and "band merging" warning flag 12 RAHR Right ascension (1950) Hours I2 14 RAMIN Right ascension (1950) Minutes I2 16 RASEC Right ascension (1950) Seconds F4.1 20 DSIGN Declination (1950) --- A1 21 DECDEG Declination (1950) Degrees I2 23 DECMIN Declination (1950) Arcminutes I2 25 DECSEC Declination (1950) Arcseconds I2 27 NH(4) Number of hours-confirmed --- 4A1 sightings 31 FLUX(4) Averaged, spatially Jy 4E8.2 [1] integrated flux density (no color correction) 63 XTALK(4) Cross-talk flag --- 4A1 [1] 67 NEARPS(4) Number of near-by weeks- --- 4A1 confirmed point sources 71 SES1(4) Number of near-by FISES entries --- 4A1 75 CIR Number of hours-confirmed, --- I2 100 micron only point sources 77 BLANK Four spare bytes --- 4A1 81 HD High source density flag --- A1 (encoded, one bit per band) 82 DBLPS Possibility this is a double --- A1 point source (1 bit per band) 83 PTSRC Name of IRAS Point Source --- 12A1 counterpart and conflict flag 95 PSIZ(4) Size estimate from comparison Deciarc- 4I3 of FLUX with PTSRC flux minutes 107 NID Number of associations --- I2 109 IDTYPE Type of objects associated --- I4 113 BLANK 48 spare bytes --- 48A1 161-180 (blank if no 12 micron component) 161 FQLT 12 micron flux quality class --- A1 [1] 162 FCAT 12 micron "final selection" flags --- A1 [1] 163 DRA Right ascension offset from Seconds F6.1 mean position to 12 micron 169 DDEC Declination offset from mean Arcseconds I4 position to 12 micron 173 UNC 95% confidence diameter for Deciarc- I3 position at 12 micron minutes 176 NS Number of individual detections --- I3 in 12 micron component 179 BLANK Two spare bytes --- 2A1 181-200 25 micron equivalent of bytes 161-180 (blank if no 25 micron component) 201-220 60 micron equivalent of bytes 161-180 (blank if no 60 micron component) 221-240 100 micron equivalent of bytes 161-180 (blank if no 100 micron component) Table 2. Format of the Small-Scale Structure Catalog Associations File Start Byte Name Description Units Format 1 NAME IRAS Source Name --- A10 12 RECNO Rec. Num. of source in data file --- I6 19 CATNO Catalog identifier --- I2 21 SOURCE Object ID in that catalog --- 15A1 36 TYPE Object type in that catalog --- 5A1 41 RADIUS Distance from IRAS source Arcseconds I3 to associated object 44 POS Position angle from IRAS Degrees I3 [1] source to object E of N 47 FIELD1 Object data field Nr 1 [2] I4 [1] (magnitude or other) 51 FIELD2 Object data field Nr 2 [2] I4 [1] (magnitude or other) 55 FIELD3 Object data field Nr 3 [2] I4 [1] (magnitude or other) [1] This quantity appears with a different format or representation, or is omitted in the printed version of the catalog. [2] The definition and units of the quantities in FIELD1-3 depend on the individual catalog in which the association is found. See Table X.B.4 in the Explanatory Supplement. Table 3. Interpretation of Final Source Selection Flag Optical N/M Detection Flux Digital Printed Binary Cross- Test Count Threshold Version FCAT Notation Talk [1] FQLT FCAT XEI FCAT ----------------------------------------------------------------------------- NO MED* PASS PASS B 0 00 00000 NO MED* PASS FAIL F 1 01 00001 NO MED* FAIL PASS F 2 02 00010 NO MED* FAIL FAIL F 3 03 00011 NO LOW PASS PASS F 4 10 00100 NO LOW PASS FAIL F 5 11 00101 NO LOW FAIL PASS F 6 12 00110 NO LOW FAIL FAIL F 7 13 00111 NO HIGH PASS PASS A 8 20 01000 NO HIGH PASS FAIL B 9 21 01001 NO HIGH FAIL PASS B A 22 01010 NO HIGH FAIL FAIL B B 23 01011 NO 2/2 PASS PASS B C 30 01100 NO 2/2 PASS FAIL F D 31 01101 NO 2/2 FAIL PASS F E 32 01110 NO 2/2 FAIL FAIL F F 33 01111 YES MED* PASS PASS F G X00 10000 YES MED* PASS FAIL F H X01 10001 YES MED* FAIL PASS F I X02 10010 YES MED* FAIL FAIL F J X03 10011 YES LOW PASS PASS F K X10 10100 YES LOW PASS FAIL F L X11 10101 YES LOW FAIL PASS F M X12 10110 YES LOW FAIL FAIL F N X13 10111 YES HIGH PASS PASS F O X20 11000 YES HIGH PASS FAIL F P X21 11001 YES HIGH FAIL PASS F Q X22 11010 YES HIGH FAIL FAIL F R X23 11011 YES 2/2 PASS PASS F S X30 11100 YES 2/2 PASS FAIL F T X31 11101 YES 2/2 FAIL PASS F U X32 11110 YES 2/2 FAIL FAIL F V X33 11111 [1] In the repeatability test, "MED*" indicates that N/M is in the intermediate range (Table IV.B.2) excluding N/M = 2/2; this latter case is indicated by "2/2".
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