VIII/42 Texas Survey of radio sources at 365MHz (Douglas+ 1996)

The Texas survey of radio sources covering -35.5{deg} < {delta} < 71.5{deg} at 365MHz

Douglas J.N., Bash F.N., Bozyan F.A., Torrence G.W., Wolfe C.

<Astron. J. 111, 1945 (1996)>

Abstract:

We present the Texas Survey of discrete radio sources between -35.5deg and 71.5deg declination (B1950), which was carried out at 365MHz with the Texas Interferometer during 1974-1983. The Survey lists accurate positions with internal errors of about an arcsecond, flux densities which for strong point sources have internal errors of about 1% and total errors of about 5%, simple structure models and indications of spectrum and variability for 66841 sources. Results of comparisons with other data are presented, and show that the Survey is 90% complete at 0.4Jy and 80% complete at 0.25Jy, is nearly free from spurious sources, and has a lobeshift incidence which is reasonably described by quality flags associated with each source.

Introduction:

The University of Texas Radio Astronomy Observatory (UTRAO) has carried out, with the Texas Interferometer, a 365MHz survey of the sky from -35.5 to +71.5{deg} declination, which was intended to be complete to a flux density level of 0.25Jy, to provide positions with an accuracy of about 1arcsec in both coordinates, to give accurate flux densities and indication of source variability, and to give rough structure models for each source.

The observations began in 1974 and were completed in 1983. A preliminary version of one declination strip was published (Douglas et al., 1980), and a number of intermediate versions of the survey have been privately circulated for various purposes pending completion of the final analysis and adjustment of the data.

File Summary:

Byte-by-byte Description of file: txs.dat

Note on Strip:

The catalog was originally decomposed in 10 tables table3a to table3j corresponding to the 10 declination strips:

Strip		Range of Decl. name
A -26		[-357,-187]
B -12		[-186,-064]
C -01		[-063,+039]
D +09		[+040,+135]
E +18		[+136,+226]
F +27		[+227,+316]
G +36		[+317,+406]
H +45		[+407,+499]
I +55		[+500,+598]
J +65		[+599,+715]

Note on TXS:

The TXS source name is constructed from the hours and minutes of right ascension, the sign of declination, and truncated tenths of degrees of declination: hhmmsddd. Because of a final position system adjustment, the source name may not agree with the position in the table, but should be used regardless.

Note on SNflg:

the Signal-to-Noise flag is set to:

X when S/N < 4

Y when 4 <= S/N < 5

Z when 5 <= S/N < 7

blank when S/N >=7

Note on Chi2 and Vstar:

values of Chi2 are statistically

> 5.99 for 5% of non-variable sources

> 9.21 for 1% of non-variable sources (Vstar set to '*')

>13.82 for 0.1% of non-variable sources

Note on Struct and q:

'P ' = Point model

'D ' = Double model

'AD' = Asymmetric Double model ;

the 'q' asymmetry parameter is then set.

Note on RAOflg and RAOZ:

* means this is one of two versions of this catalog line, because the source was in an RA overlap zone; the RA zone is then given in the RAOZ column.

Note on DEOflg and DEOZ:

* means this is one of two versions of this catalog line, because the source was observed separately in two observation declination strips; the DE zone is then given in the DEOZ column.

Note on strp:

observation strip and segment from which the catalog line was obtained. For example, in TXS 0000+178, strp=181 means that the catalog line came from the +18{deg} observation strip, RA segment 1. Some sources came from Version 6 of the Texas Survey ('TS6' in strp field) or Version 7 ('TS7' in strp field)

Byte-by-byte Description of file: simpler.dat

Note on TXS:

The name is that of the corresponding Survey source line in file txs.dat

Note on Struct:

Point model is 'P'; Double model is 'D'; there are no AD models in the "Simpler models".

History:

AAS CD-ROM series, Volume 6, 1996.

* At CDS, October 1996:

The original 'table3*' tables were merged into the "txs.dat" file, and 'table4*' tables into the "simpler.dat" file, but the table number was inserted in byte one.

References:

Douglas J.N., Bash F.N., Torrence G.W., & Wolfe C., 1980, Publ. Dept. Astron. Univ. Texas, No 17, October 1980.

(End) Francois Ochsenbein [CDS] 23-Oct-1996