[Adapted from the ADC catalog file]
The 1.2-Jy IRAS Redshift Survey is an ASCII file containing 5014
records in the format described in Table 1.
|Table 1. Format of the Survey File
||Right Ascension 1950.
||Right Ascension 1950.
||Right Ascension 1950.
||Averaged, non-color corrected flux density, in compact form, one value per band (see below)
||Type of Object
||Number of nearby weeks confirmed small extended sources.(1 value for all bands)
||Point source correlation coefficient (60 micron band)
||Variability in 12 and 25 micron bands (see below)
||Identification of the source (see below)
||Flux density quality. (1 value per band)
||Optical identification (see below)
||Optical magnitude of ID'ed galaxy
||Uncertainty in velocity
||ZCAT code of source of redshift
||Type of galaxy in ZCAT
||Either UGC or ESO number of the galaxy
||Total magnitude, as defined in RC2, when available
||Internal index for the optical spectrum in the CfA database, if one exists
||Comments taken from ZCAT
||Averaged, non-color corrected flux density as listed in the
PSC, one value per
band, encoded as NF above
The coordinates for all objects that appear in the
Point Source Catalog Version 2, are
from that source; there are also a few very
large galaxies whose fluxes and coordinates are taken from the
Large Optical Galaxy Catalog.
- Coded Flux Density: NF(4)
- Each of the four wavelengths has a non-color-corrected flux density in
units of Janskys, (1 Jy = 1.0E-26 W m-2 Hz-1). The quoted value is an
average of all the hours-confirmed sightings as obtained by the prescription
described in Explanatory Supplement V.H.5. The quality of each flux
density is designated by FQUAL (see below). The flux densities have been
calculated assuming an intrinsic source energy distribution such that
the flux density f(nu) is proportional to 1/nu. Corrections to other
spectral shapes can be made (see the description of color correction). The flux densities for sources
so bright that they saturated the analog-to-digital converter on every
sighting are lower limits based on the brightest value recorded. The
uncertainties are given as ten times the quoted flux density and a flag
is set in the CLEAN bits of the corresponding entry in the Ancillary Working Survey Database entry
indicating saturation has occurred.
- The IRAS fluxes are coded in a compact logarithmic form:
The 12 micron flux is related to the integer NF12 by
F12 = 10.^(NF12/1000 - 1.); similarly for the other fluxes. The fluxes are
taken from the PSC, unless:
In these cases, one-dimensional addscan's of the data have been obtained
and the zero-crossing fluxes from the median scan in all four bands, as
supplied by SCANPI, have been determined.
- The object is extended at 60 microns (see SES2 below);
- The object is variable (see VARFLAG below);
- The object is of moderate flux quality at 60 microns (see FQUAL below).
Those sources flagged as extended in Rice et al. (1988, ApJS,
68, 91) have fluxes from that source. The ID type is taken directly
from the the Format of the
- Small Extended Sources: SES2
- This is related to the SES2 flag in the Format of the Point Source Catalog. The SES2 flag indicates whether or not an
object is flagged as extended (SES2 > 0, for a given band, in the PSC).
||Extended at 12 microns
||Extended at 25 microns
||Extended at 12 and 25 microns
||Extended at 60 microns
||Extended at 12 and 60 microns
||Extended at 25 and 60 microns
||Extended at 12, 25, and 60 microns
||Extended in Rice et al. 1988, ApJS, 68, 91
- Point Source Correlation: CC
- This is the same as the CC entry for the 60 micron band in the
Format of the Point Source Catalog. The
point source correlation coefficient can have values between 87-100%.
These are encoded as alphabetic characters with A=100, B=99...N=87, one
value per band. The value quoted is for the highest correlation
coefficient seen for that source on any sighting.
Status flag: STATUSFLAG
The STATUSFLAG indicates the identification of the source, and, if it is a
galaxy, the source of the redshift:
- Variability Flag: VARFLAG
- This is derived from the VAR flags in the
Format of the Point Source Catalog. VARFLAG here is a measure of
variability in the 12 and 25 micron bands.
n No measure of variability available.
0 No variability measured.
N Variability between 1 and 10%.
1 Variability between 10 and 20%
and so on.
These labels are by no means complete; only a fraction of these
sources were observed at the telescope for this study. See Strauss
et al. 1992 (ApJS, 83, 29) and Yahil et al. 1991 (ApJ, 372, 380) for
discussion of the estimated number of sources flagged as cirrus that
are indeed galaxies.
Flux density quality: FQUAL(4)
As in the Format of the Point Source
Catalog. A flux density measurement can be either high quality
(FQUAL=3), moderate quality (FQUAL=2) or an upper limit (FQUAL=1). One
number is given for each band.
Optical identification: OPTID
Optical identification is from a matching of the combined UGC,
Zwicky, and NGC catalogs, and is not complete. (Occasionally, these
columns will contain obvious junk, which should be ignored.)
Optical magnitude: MAG
Magnitudes are from the same source as OPTID, and again are not complete.
Redshift: VEL, VELERR
Redshifts and errors are either as quoted in the literature, or
measured by the authors (see Strauss et al. 1992, ApJS, 83, 29).
All velocities are heliocentric.
ZCAT code of source: SOURCE
A four-digit number that codes the redshift source from ZCAT.
Galaxy type: TTYPE
The type of the galaxy from ZCAT.
Galaxy number: UNUMBER
Either the UGC or ESO number of the source.
RC2 magnitude: BT
The total magnitude, as defined in the RC2, for those few galaxies
that have them.
Index of spectrum: SPECTRUM
An internal index for the optical spectrum, if one exists, of the
galaxy in the CfA database.
ZCAT comments: COMMENTS
The comments for the galaxy in ZCAT.
Coded Flux Density: PF(4)
Fluxes of the source as listed in the Point Source
Catalog for those sources with ADDSCAN fluxes in columns
16-31; they are coded the same way as the fluxes NF (see above).
- Galaxies: O,H,Z,F,B,D. The distinction between these is uninteresting,
although Z indicates a source drawn from John Huchra's private version of ZCAT.
- L: Local Group galaxy. This is given a separate flag.
- M: HII region in external galaxy.
- S: Star
- s: Emission line star
- C: Cirrus or dark cloud
- P: Planetary nebula
- R: Reflection Nebula
- ? or E: Unidentified field.