J/A+A/35/393 Westerbork Second Deep Survey (Katgert 1974)
A Second Deep Survey with the Westerbork telescope at 1415 and 610 MHz: an
attempt to obtain deep identifications.
Katgert J.K.
<Astron. Astrophys. 35, 393 (1974)>
=1974A&A....35..393K 1974A&A....35..393K
ADC_Keywords: Radio sources ; Surveys ;
Keywords: radio survey - deep informations - source counts -
spectral index distribution - faint radio galaxies
Abstract:
A radio survey has been made of an area centered at 01h 03min
+29°, using the Westerbork telescope at 1415MHz. The completeness
limit of the survey is 7mJy. Additional observations have been made
at 610MHz. The Lick 120" telescope has been used to obtain deep
(O98-O2 emulsion) plates to serve as an optical counterpart. A
catalogue is presented of 58 sources found in the survey. 53 of these
comprise a complete sample. 31 sources of the complete sample lie in
areas of which Lick plates were taken. Of the sources in Lick plates
areas, 11 could be identified with galaxies and 3 with possible QSO's,
yielding an identification percentage of 46. For the other 22 sources
an identification programme was carried out using Palomar Sky Survey
prints and other large 48" Schmidt plates: three of these sources
could be identified with galaxies and two with possible QSO's. The
survey was also used to derive source counts and a spectral index
distribution. The source counts agree well with those derived for an
earlier survey. The spectral index distribution has a mean of 0.52 and
a width of 0.39. the explanation for the flatter spectra is not clear
but might possibly lie in another source population that begins to
dominate the results at low flux densities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 168 59 The catalogue
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See also:
VIII/19 : Catalogues from a deep 327 MHz Westerbork Survey (Wieringa 1991-93)
VIII/62 : The Westerbork Northern Sky Survey (Leiden, 1998)
J/A+AS/58/1 : 1412 MHz catalogue of Westerbork survey. I. (Windhorst+, 1984)
J/A+AS/58/39 : 1412 MHz catalogue of Westerbork survey. II (Windhorst+, 1984)
J/A+AS/124/259 : Westerbork Northern Sky Survey I. (Rengelink+ 1997)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1 A1 --- n_2W [+] +: source not in the complete sample
2- 11 A10 --- 2W Source name, 2W HHMM+DDWNA (1)
13- 14 I2 h RAh Right ascension (1950.0)
16- 17 I2 min RAm Right ascension (1950.0)
19- 23 F5.2 s RAs Right ascension (1950.0)
25- 27 F3.2 s e_RAs rms uncertainty on RA
29 A1 --- DE- Declination sign (1950.0)
30- 31 I2 deg DEd Declination (1950.0)
33- 34 I2 arcmin DEm Declination (1950.0)
36- 40 F5.2 arcsec DEs Declination (1950.0)
42- 45 F4.1 arcsec e_DEs rms uncertainty on DE
47- 51 F5.1 mJy S1415MHz 1415 MHz flux density (2)
53- 56 F4.1 mJy e_S1415MHz rms uncertainty on S1415MHz
58- 62 F5.2 mJy aS1415MHz Correction for attenuation, due to the
1415 MHz primary beam pattern.
64- 68 F5.2 mJy aS1415MHz2 ? Second correction for attenuation (3)
70- 73 F4.2 mJy aS1415MHz3 ? Third correction for attenuation (3)
75- 79 F5.2 mJy aS1415MHz4 ? Fourth correction for attenuation (3)
81- 85 F5.1 mJy S610MHz ? 610 MHz flux density
87- 91 F5.1 mJy e_S610MHz ? rms uncertainty on S610MHz
93- 96 F4.2 mJy aS610MHz ? Correction for attenuation due to the
610 MHz primary beam antenna pattern
98-102 F5.2 --- Sp-Index ? Spectral index α from 1415 to
610 MHz (S(ν)~ν^-α)
104-106 F3.1 --- Weight ? Weight with which the source enters
the spectral index distribution,
normalized to a sample size of fifty
108 A1 --- Res [UR] Information on resolution:
U = not noticeably resolved,
R = noticeably resolved
110-111 I2 arcsec Ext ? Angular extent of the resolved source
113-115 I3 deg PA ? Position angle of the resolution,
measured from North through East
116 A1 --- n_PA [+] +: possible core-halo source
117-119 I3 deg PA2 ? Second position angle
120-122 A3 --- Type Type of identification (GAL or QSO)
123 A1 --- u_Type [?] Uncertainty flag on Type
125 A1 --- Note [+] +: identification was obtained from
one of the Lick plates
127-130 F4.1 mag mag ? Estimate of the magnitude of the
identification (4)
132-171 A40 --- Rem Remarks
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Note (1): The sources have been named according to a modified Parkes system.
The nomenclature is described in a previous paper
(Katgert et al, 1973A&A....23..171K 1973A&A....23..171K).
Note (2): Corrections for resolution, if any, and for primary beam pattern
attenuation have been applied.
Note (3): When the source was detected in more than one field
Note (4): For a large part of the magnitude range standards were not easily
available, so the estimates are extrapolated and may be wrong by more
than 1mag.
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History:
Originally OCRed by H. Andernach, proofread at CDS.
(End) James Marcout, Patricia Bauer [CDS] 18-Apr-2001