User's Manual - Catalog of Infrared Observations

[Catalog Description] [Journal List] [Database Contents] [Flux Units] [Cautions]

What Is the CIO?

The Catalog of Infrared Observations (CIO) is a machine-readable compilation of infrared (1 micron - 1 mm) astronomical observations published in the scientific literature. This infrared database, maintained at NASA/Goddard Space Flight Center, contains observational data for astronomical sources outside the solar system obtained through a search of the most active astronomy journals, infrared surveys, and catalogs. To date, about 6900 journal articles and 10 major survey catalogs have been included in this database, which contains over 396,000 individual observations for the period 1965 through 1998.

Literature Included in the CIO Database

The Catalog contains observational data obtained from a search of the following infrared catalogs and scientific journals for the years 1965-1998, inclusive. The number of articles in each journal containing infrared astronomical data and the journal abbreviations used in the bibliography are indicated.
       Scientific Journals Searched (1965-1998, complete):

  757  Astronomical Journal (A.J.)
 1355  Astronomy and Astrophysics (Astr. & Ap.)
  171  Astronomy and Astrophysics Suplement (Astr. & Ap. Suppl.)
 2037  Astrophysical Journal (Ap.J.)
  866  Astrophysical Journal Letters (Ap.J. Letters)
  138  Astrophysical Journal Supplement Series (Ap.J. Suppl.)
 1045  Monthly Notices of the Royal Astronomical Society (M.N.R.A.S.)
  243  Publications of the Astronomical Society of the Pacific (P.A.S.P.)

       Infrared Catalogs:

       Infrared Astronomical Satellite (IRAS) Point Source Catalog,
        Version 2.0 (880001)
       IRAS Small Scale Structure Catalog (851123)
       Caltech Two-Micron Sky Survey (690001)
       Revised AFGL Four-Color Infrared Sky Survey Catalog (830610)
       Equatorial Infrared Catalog, version 2 (90001)
       Far Infrared Sky Survey Experiment (830201)

       Other Journals Searched (all years not complete):

       Annals d'Astrofisica (Ann. d'Ast.)
       Astrophysics and Space Science (Ap. & Sp. Sci.)
       Astrophysical Letters (Ap. Letters)
       Communications of the Lunar and Planetary Laboratory (Comm. L.P.L.)
       Earth and Extraterrestrial Sciences (Earth and Ext. Sci.)
       I.A.U. Circulars (I.A.U. Circ.)
       Chinese Astronomy (Chi. Ast.)
       Comments on Astrophysics (Comm. on Ap.)
       Memoirs of the Royal Astronomical Society (Mem. R.A.S.)
       Monthly Notices of the Astronomical Society of South Africa
       Nature and Nature Physical Sciences
       Proceedings of the Astronomical Society of Australia (Proc. A.S.A.)
       Publications of the Astronomical Society of Japan (P.A.S.J.)
       Soviet Astronomy (Sov. Ast.)
       Soviet Astronomy Letters (Sov. Ast. Letters)
       Tokyo Astronomical Bulletin (Tokyo Ast. Bul.)
       Zeitschrift fur Astrophysik (Zeit. fur Ap.)
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Contents of the CIO Database

This on-line version of the CIO contains 1) revision 5.1 (December 2000) of the main Catalog, 2) an Atlas listing the sources and positions in alphabetical order, and 3) bibliographic references grouped alphabetically by author.
All of the on-line data, plus spectral ranges and IRAS Point Source Catalog fluxes for CIO sources, along with a chronological reference list, are contained in downloadable files. Please see the Download Page for more information.

Column Descriptions


     Column          Description

     NAME            Source name as given in article
     RA              Right Ascension (1950)
     DEC             Declination (1950)
     LAMBDA          Wavelength in microns
     FLUX            Source flux and associated unit (See FLUX below)
     BEAM            Aperture size  (see BEAM below)
     BIBLIO          Bibliographic reference code (See BIBLIO below)
     PSC NAME        Source name in the IRAS Point Source Catalog (PSC)
     PSC FLUX        Order-of-magnitude PSC flux at 12, 25, 60, 
                          and 100 microns (See IRAS below)
     PSC CODE        PSC quality codes for each wavelength (See IRAS below) 
FLUX (Cols. 45-49)-- The infrared flux is listed in the same units as published by the original observers. The units have been given one- or two-letter abbreviations (see UNITS file). To protect the integrity of the database, no attempt has been made to convert these different units of infrared flux into a more homogeneous system. Fortunately, about 95% of the flux observations in the Catalog have units of "magnitudes" or "Janskys," or have commonly used units (B, E, F, I, X). The remaining 2% of the entries are in less common units, but these are dimensionally equivalent to one of the more commonly used units. In general, infrared magnitudes are calibrated with respect to the flux density of Alpha Lyr (10^4 K blackbody), which is defined as being 0 magnitude at all infrared wavelengths (see Gillett et al., 1971, Ap.J., 164, 83; Gehrz and Woolf, 1971, Ap.J., 165, 185).
The following letters may be appended to the flux unit: V = variable or mean of several values; L = lower limit (detector saturated); U = upper limit; E = editor determined flux from maps, spectra, or other material in the article not in tabulated form.
When spectral data (S) are listed, only the starting wavelength of the spectrum appears in the Lambda(microns) column. Starting and ending wavelengths of published spectra are given in the spectra.dat file.

BEAM -- The angular beam size of the observation is presented in degrees (D), arcminutes (M), or arcseconds (S). If no beam size information was given in the original reference, a dash (-) is entered. In addition to being a factor in source brightness calculation, the beam size can be used as an aid in determining positional coincidences and identifications with other sources, and as a first-order indication of positional accuracy.

BIBLIO (Cols. 52-57)-- The bibliographic reference code identifies the original journal article for each observation in the Catalog, keyed to the chronological refchron.dat file. The bibliographic reference number is made up of the year and month of publication, and a sequential number is assigned to the article (for example, "790104" breaks down into 79-01-04, where 79 = 1979, 01 = January, and 04 = article randomly assigned as #4 in that month). References that do not indicate the month of publication have "00" in the month field.

IRAS (Cols. 58-68)-- The large number of sources (245,000) in the IRAS Point Source Catalog (PSC) would clearly overwhelm the CIO. Criteria had to be established to include IRAS data without changing the basic nature of the Catalog. Order-of-magnitude IRAS PSC fluxes have been included in the main Catalog files for all CIO sources which were also detected in the IRAS PSC Version 2.0 (about 27,000 of the individual sources listed in this edition of the CIO). The four digits used represent the approximate logarithm of the flux density in each of the four IRAS bands. For example, "0012" means that the source listed has fluxes of roughly 1, 1, 10, and 100 Janskys in IRAS bands 1, 2, 3, and 4 (12, 25, 60, and 100 microns), respectively. The numbers used in this notation are specifically 0 = < 5 Jy, 1 = 5-50 Jy, 2 = 50-500 Jy, 3 = 500-5000 Jy, etc. Exact values for the PSC fluxes of CIO sources can be obtained from the PSC files, which list positions and fluxes from version 2.0 of the Point Source Catalog (see below). The PSC quality codes are: blank = high; : = moderate; U = upper limit; S = saturated.


     Contents        Description
     NAME            Source name
     RA              Right Ascension (1950)
     DEC             Declination (1950)

References are listed alphabetically by first author's name and include journal name, volume, page, and article title.

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Flux Units in the CIO

The following flux unit abbreviations are used by the Catalog of Infrared Observations.
Note: a caret is used to indicate exponents.
  Abbreviation  Definition                                   No. of Journals
                                                                Using Unit
       A        normalized magnitude                               29
       B        10^(-19) W m^(-2) Hz^(-1) Sr^(-1)                  47
       C        magnitude, derived from color                     558
       D        diameter measurement                              187
       E        erg sec^(-1) cm^(-2) Sr^(-1)                       78
       F        10^(-16) W cm^(-2) micron^(-1)                    134
       G        10^(-14) ergs sec^(-1) cm^(-2)                    186
       H        log(ergs sec^(-1) cm^(-2) Hz^(-1))                 14
       I        10^(-9) W cm^(-2) micron^(-1) Sr^(-1)              16
       J        10^(-26) W m^(-2) Hz^(-1) = 1 Jansky             1185
       JA       Janskys arcsec^(-2)                                 2
       K        log(10^(-26) W m^(-2) Hz^(-1))                     20
       L        log(W m^(-2) Hz^(-1))                              12
       M        magnitude                                        2572
       MA       magnitudes arcsec^(-2)                             52
       N        log(ergs sec^(-1) cm^(-2) micron^(-1))              6
       P        polarization data                                 308
       Q        log(10^(-3) Jansky)                                 6
       R        log(W cm^(-2) micron^(-1))                          8
       S        spectral data                                    1809
       T        -2.5 log(ergs sec^(-1) cm^(-2) Hz^(-1)) - 48.60     9
       U        upper limit                                          
       V        variable                                             
       W        10^(-14) W m^(-2)                                 179
       X        10^(-18) W cm^(-2)                                229
       Y        relative line intensity                            50
       Z        10^(-21) W cm^(-2) micron^(-1) arcsec^(-2)          5
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Please note the following special characteristics of this Catalog:
  1. Sky coverage is not uniform. The Catalog data are a mixture of sky surveys, small-scale regions surveys, and numerous individual source observations. The whole sky has been surveyed only at a few wavelengths, and then to varying levels of sensitivity. Non-survey observations are not spatially homogeneous.

  2. Data are presented in original published form. No attempt has been made to create a single system of infrared photometric units, or to eliminate redundant observations. This kind of interpretation is more appropriately done by the individual researcher.

  3. The Catalog is as accurate as the published data from which it was constructed. Observations listed here were made by hundreds of investigators, using different instrumental techniques and methods of analysis.
The user of this Catalog must therefore approach it with the same kind of professional skepticism which would be applied to the original journal articles.

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Last modified: November 30, 2000

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