ACDS V10.0 - Sun Apr 21 02:16:18 CEST 2019
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Detailed Description of II/156A :
IRAS Faint Source Catalog, |b| > 10, Version 2.0 (Moshir+ 1989)
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Note : this is the description file of the original catalog.
This HTML page corresponds well to the original description, but some minor
changes in the format may have been introduced in the FITS output
files in order to allow for arithmetic operations on quantities
such as coordinates and times. h:m:s and d:m:s units are normally
converted into degrees, and YYYY-MM-DD into julian days.
Similarly, some slight changes may have been introduced in the
units; the value given in the HTML files supersedes the value indicated in the ReadMe
file for this catalogue.
II/156A IRAS Faint Source Catalog, |b| > 10, Version 2.0 (Moshir+ 1989)
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IRAS Faint Source Catalog, |b| > 10 Degrees, Version 2.0
Moshir, M., Copan, G., Conrow, T., McCallon, H., Hacking, P., Gregorich, D.,
Rohrbach, G., Melnyk, M., Rice, W., Fullmer, L., and Chester, T.J.
<Infrared Processing and Analysis Center (1989)>
=1990IRASF.C......0M
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ADC_Keywords: Infrared sources ; Photometry, infrared ; Surveys
Mission_Name: IRAS
Description:
The Faint Source Survey (FSS) is the definitive Infrared Astronomical
Satellite data set for faint point sources. The FSS was produced by
point-source filtering the individual detector data streams and then
coadding those data streams using a trimmed-average algorithm. The
resulting images, or plates, give the best estimate from the IRAS
survey data of the point source flux density at every surveyed point
of the sky. The Faint Source Catalog (FSC) is a compilation of the
sources extracted from the FSS plates that have met reasonable
reliability requirements. Averaged over the whole catalog, the FSC is
at least 98.5% reliable at 12 and 25 microns, and ~94% at 60 microns.
For comparison, the IRAS Point Source Catalog (PSC) is >99.997%
reliable, but the sensitivity of the FSC exceeds that of the PSC by
about a factor of 2.5. The FSC contains data for 173,044 point sources
in unconfused regions with flux densities typically above 0.2 Jy at
12, 25, and 60 microns, and above 1.0 Jy at 100 microns. The FSS
plates are somewhat more sensitive but less reliable than the FSC;
typically, only sources with SNR>5-6 in the plates are contained in
the FSC. Sources with SNR>3 but which do not meet the reliability
requirements of the FSC are catalogued in the Faint Source Reject File
(FSR, Cat. II/275). The data products, the processing methods used to
produce them, results of an analysis of these products, and cautionary
notes are given in the Explanatory Supplement to the IRAS Faint Source
Survey (see references in fsc.txt).
File Summary:
FileName Lrecl Records Explanations
× 80 . This file
× ReadMe 80 . This file
× fsc.txt 84 897 Original description (ADC CD-ROM Vol. 1, 1991)
× SIMPLE.fih 80 60 FITS header
× main.dat 227 173044 IRAS Faint Sources
× main.fih 80 306 associated FITS header
× assoc.dat 64 235935 Associations
× assoc.fih 79 94 associated FITS header
× meaning.txt 80 304 Details of association catalogues
× tofits.sh 80 74 Unix shell to generate FITS (1)
Note (1): This small script should run on any Unix platform.
To generate the FITS version of the tables, execute
./tofits main > main.fits (for the main table)
./tofits assoc > assoc.fits (for the association file)
See also:
II/125 : IRAS Point Source Catalog (IRAS-PSC)
II/126 : IRAS Serendipitous Survey Catalog (IRAS-SSC, sources SHHMMm+DDMMA)
II/274 : IRAS Point Source Reject Catalog (IRAS-PSR, sources RHHMMm+DDMM)
II/275 : IRAS Faint Source Reject Catalog (sources IRAS ZHHMMm+DDMMA)
VII/73 : IRAS Small Scale Structure Catalog (IRAS-SSSC, sources XHHMM+DDd)
II/174 : IRAS 2Jy Redshift Survey Data File
II/190 : IRAS Minor Planet Survey Data Base
VII/91 : IRAS Asteroid and Comet Survey
VII/109 : IRAS Observations of Large Optical Galaxies
VII/113 : Catalogued Galaxies + QSOs observed in IRAS Survey
Byte-by-byte Description of file: main.dat
Bytes Format Units Label Explanations
1- 12 A12 --- IRAS IRAS faint source name (starts by F)
13- 14 I2 h RAh Hours RA, equinox 1950.0, epoch 1983.5
15- 16 I2 min RAm Minutes RA, equinox 1950.0, epoch 1983.5
17- 19 I3 0.1s RAds Deci-seconds RA
20 A1 --- DE- Sign of DEC, equinox 1950.0, epoch 1983.5
21- 22 I2 deg DEd Degrees Dec, equinox 1950.0, epoch 1983.5
23- 24 I2 arcmin DEm Minutes Dec, equinox 1950.0, epoch 1983.5
25- 26 I2 arcsec DEs Seconds Dec, equinox 1950.0, epoch 1983.5
27- 29 I3 arcsec Major Uncertainty ellipse major axis
30- 32 I3 arcsec Minor Uncertainty ellipse minor axis
33- 35 I3 deg PosAng Uncertainty ellipse position angle
36- 38 I3 --- o_Fnu12 ? Number of times observed at 12um
39- 41 I3 --- o_Fnu25 ? Number of times observed at 25um
42- 44 I3 --- o_Fnu60 ? Number of times observed at 60um
45- 47 I3 --- o_Fnu100 ? Number of times observed at 100um
48- 56 E9.3 Jy Fnu12 Non-color corrected flux density at 12um
57- 65 E9.3 Jy Fnu25 Non-color corrected flux density at 25um
66- 74 E9.3 Jy Fnu60 Non-color corrected flux density at 60um
75- 83 E9.3 Jy Fnu100 Non-color corrected flux density at 100um
84 I1 --- q_Fnu12 Flux density quality at 12um
85 I1 --- q_Fnu25 Flux density quality at 25um
86 I1 --- q_Fnu60 Flux density quality at 60um
87 I1 --- q_Fnu100 Flux density quality at 100um
88- 90 I3 % e_Fnu12 Relative flux density uncertainty at 12um
91- 93 I3 % e_Fnu25 Relative flux density uncertainty at 25um
94- 96 I3 % e_Fnu60 Relative flux density uncertainty at 60um
97- 99 I3 % e_Fnu100 Relative flux density uncertainty at 100um
100-101 I2 % Rel Percent minimum source reliability
102-108 E7.1 --- SNR12 ? Signal/Noise ratio at 12um
109-115 E7.1 --- SNR25 ? Signal/Noise ratio at 25um
116-122 E7.1 --- SNR60 ? Signal/Noise ratio at 60um
123-129 E7.1 --- SNR100 ? Signal/Noise ratio at 100um
130-136 E7.1 --- locSNR12 ? Local Signal/Noise ratio at 12um
137-143 E7.1 --- locSNR25 ? Local Signal/Noise ratio at 25um
144-150 E7.1 --- locSNR60 ? Local Signal/Noise ratio at 60um
151-157 E7.1 --- locSNR100 ? Local Signal/Noise ratio at 100um
158-160 I3 pix A12 ? Number of pixels above threshold at 12um
161-163 I3 pix A25 ? Number of pixels above threshold at 25um
164-166 I3 pix A60 ? Number of pixels above threshold at 60um
167-169 I3 pix A100 ? Number of pixels above threshold at 100um
170-171 I2 --- Ncat Number of nearby catalog sources (6')
172-173 I2 --- Nx12 Number of nearby extractions at 12 um
174-175 I2 --- Nx25 Number of nearby extractions at 25 um
176-177 I2 --- Nx60 Number of nearby extractions at 60 um
178-179 I2 --- Nx100 Number of nearby extractions at 100 um
180-181 I2 --- Cir1 Number of nearby 100 um-only extractions
182-183 I2 --- Conf Confusion flag, 1 per band, bit-encoded (1)
184-188 F5.2 --- NoisC12 ? Noise correction factor at 12um
189-193 F5.2 --- NoisC25 ? Noise correction factor at 25um
194-198 F5.2 --- NoisC60 ? Noise correction factor at 60um
199-203 F5.2 --- NoisC100 ? Noise correction factor at 100um
204-205 I2 --- nID ? Number of positional associations
206-207 I2 --- Type ? Type of associated object (G1)
208-212 F5.3 --- NoisR12 ? Ratio of 85% to 68% quantiles of flux
distribution at 12um
213-217 F5.3 --- NoisR25 ? Ratio of 85% to 68% quantiles of flux
distribution at 25um
218-222 F5.3 --- NoisR60 ? Ratio of 85% to 68% quantiles of flux
distribution at 60um
223-227 F5.3 --- NoisR100 ? Ratio of 85% to 68% quantiles of flux
distribution at 100um
Note (1): corresponding to 12, 25, 60 and 100um from lowest to highest bit.
Therefore the confusion flags are set in the bands as follows:
1 = confusion in 12um band
2 = confusion in 25um band
4 = confusion in 60um band
8 = confusion in 100um band
Confusion in multiple bands are expressed by a sum of the values,
e.g. 12 (8+4) means a confusion in 60 and 100µm bands.
Byte-by-byte Description of file: assoc.dat
Bytes Format Units Label Explanations
1- 12 A12 --- IRAS IRAS source name
13- 18 I6 --- RecNo Main data table record number for IRAS source
19- 20 I2 --- catID Catalog number, details in file "meaning.txt"
21- 35 A15 --- Source Source identification
36- 40 A5 --- Type Source type or spectral class, or association
catalog type (G1)
41- 43 I3 arcsec Dist Distance of IRAS source to association
44- 46 I3 deg dPA Position angle from IRAS source to association
47- 49 I3 arcsec dMaj Distance from IRAS source to association
along major axis of IRAS uncertainty ellipse
50- 52 I3 arcsec dMin Distance from IRAS source to association
along minor axis of IRAS uncertainty ellipse
53- 56 I4 --- Field1 ?=-999 Object data field 1, catalog dependent
57- 60 I4 --- Field2 ?=-999 Object data field 2, catalog dependent
61- 64 I4 --- Field3 ?=-999 Object data field 3, catalog dependent
Global Notes:
Note (G1): Type ranges from 1 to 15 and states whether an association
was found in:
* a stellar catalogue (bit 0 = 1) (*)
* an extragalactic catalog (bit 1 = 2) (*)
* catalogs with other types of objects (bit 2 = 4) or
* in a catalog with mixed types (bit 3 = 8).
For example, if associations were found to both an extragalactic
catalog and a stellar catalog, Type is set to 3 (2+1).
(*) The meaning of these two bits are different from what is stated
in the original documentation "fsc.txt" file.
History:
* Original description from Susan Gessner (NASA/GSFC) in 1989
(see file "fsc.txt")
* 24-Feb-1993: standardized documentation at CDS
* 30-Jan-2009: description homogenized with other IRAS catalogs at CDS.
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(End) 24-Feb-1993