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VIII/65             1.4GHz NRAO VLA Sky Survey (NVSS)      (Condon+ 1998)

The NRAO VLA Sky Survey Condon J.J., Cotton W.D., Greisen E.W., Yin Q.F., Perley R.A., Taylor G.B., Broderick J.J. <Astron. J. 115, 1693 (1998)> =1998AJ....115.1693C
ADC_Keywords: Radio sources ; Radio continuum ; Surveys Description: The NRAO VLA Sky Survey (NVSS) is a radio continuum survey covering the sky north of -40° declination at 1.4GHz. The principal data products of the NVSS are a set of 2326 4x4° continuum "cubes" with three planes containing Stokes I, Q, and U images, plus a catalog of almost 2 million discrete sources stronger than a flux density of about 2.5mJy. The images all have 45 arcsecond FWHM angular resolution and nearly uniform sensitivity. Their rms brightness fluctuations are approximately 0.45mJy/beam=0.14K (Stokes I) and 0.29mJy/beam=0.09K (Stokes Q and U). The rms uncertainties in right ascension and declination vary from ≤ ∼1arcsecond for the 400,000 sources stronger than 15mJy to 7arcseconds at the survey limit. A more detailed description is provided in the printed paper and at the NVSS website at where all data products, user software, and updates were released as soon as they were produced and verified. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file nvss.dat 158 1773484 The NVSS Catalog
See also: VIII/59 : the FIRST Survey, version 1999Jul (White+ 1999) : the NVSS Home Page Byte-by-byte Description of file: nvss.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Field Name of the original survey image field from which the component was derived. 10- 16 F7.2 pix Xpos X position (RA direction) of the radio source 18- 24 F7.2 pix Ypos Y position (Dec direction) of the radio source 26- 39 A14 --- NVSS Source name (1) 41- 42 I2 h RAh Right Ascension J2000 (hours) (2) 44- 45 I2 min RAm Right Ascension J2000 (minutes) (2) 47- 51 F5.2 s RAs [0,60] Right Ascension J2000 (seconds) (2) 53 A1 --- DE- Declination J2000 (sign) (2) 54- 55 I2 deg DEd Declination J2000 (degrees) (2) 57- 58 I2 arcmin DEm Declination J2000 (minutes) (2) 60- 63 F4.1 arcsec DEs [0,60] Declination J2000 (seconds) (2) 65- 69 F5.2 s e_RAs Mean error on RA 71- 74 F4.1 arcsec e_DEs Mean error on Dec 76- 83 F8.1 mJy S1.4 Integrated 1.4GHz flux density of radio source 85- 91 F7.1 mJy e_S1.4 Mean error on S1.4 93 A1 --- l_MajAxis Limit flag on MajAxis 94- 98 F5.1 arcsec MajAxis Fitted (deconvolved) major axis of radio source 100 A1 --- l_MinAxis Limit flag on MinAxis 101-105 F5.1 arcsec MinAxis Fitted (deconvolved) minor axis of radio source 107-111 F5.1 deg PA [-90, 90]? Position angle of fitted major axis 113-116 F4.1 arcsec e_MajAxis ? Mean error on MajAxis 118-121 F4.1 arcsec e_MinAxis ? Mean error on MinAxis 123-126 F4.1 deg e_PA ? Mean error on PA 128-129 A2 --- f_resFlux [PS* ] Residual Code (3) 131-134 I4 mJy resFlux ? Peak residual flux, in mJy/beam (3) 136-141 F6.2 mJy polFlux ? Integrated linearly polarized flux density 143-147 F5.1 deg polPA *[-90,90]? The position angle of polFlux (4) 149-153 F5.2 mJy e_polFlux ? Mean error on polFlux 155-158 F4.1 deg e_polPA ? Mean error on polPA
Note (1): The NVSS Catalog designation is of the form NVSS JHHMMSS+DDMMSS using the standard IAU nomenclature prescription, where NVSS is the catalog acronym, J specifies the coordinate equinox (for J2000) HHMMSS are the hours, minutes, and truncated (not rounded) seconds of right ascension, + or - is the sign of the declination, and DDMMSS are the degrees, arcminutes, and truncated (not rounded) arcseconds of declination. Thus, the NVSS source at equinox J2000.0 coordinates of 00h00m00.24s -20d04'49.1" is called NVSS J000000-200449. This name, without the leading "NVSS J" prefix, is reported in the NVSS column. There are four cases where a suffix "a" or "b" have been appended to the name to ensure the naming unicity. Note (2): Position of the centroid of the fitted radio source, for the epoch of observation (1995±2). Note (3): High residual values generally indicate complex sources. f_resFlux contains a flag indicating a residual of the fit to the radio source, which can be: P: if the peak flux density residual was high S: if the integrated flux density residual was high Note (4): polPA is the position angle (N through East) of the "E" vector of the linear polarization if the source was detected (1 sigma) in linear polarization.
History: The file "nvss.dat" was created from the ascii edition of NVSS as file (27-Sep-2002), provided by the NVSS Catalog's authors. Many of the descriptions enclosed in this ReadMe file were prepared by the HEASARC team at
(End) Francois Ochsenbein [CDS] 24-Dec-2002
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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