J/AJ/137/4846 90cm observations of the deep SWIRE field (Owen+, 2009)
The deep SWIRE field. II. 90cm continuum observations and 20 cm-90 cm spectra.
Owen F.N., Morrison G.E., Klimek M.D., Greisen E.W.
<Astron. J. 137, 4846-4853 (2009)>
=2009AJ....137.4846O 2009AJ....137.4846O
ADC_Keywords: Radio sources ; Surveys
Keywords: cosmology: observations - galaxies: active - galaxies: evolution
galaxies: general - galaxies: starburst
Abstract:
We present one of the deepest radio continuum surveys to date at a
wavelength ≳1m. The observations were taken with the VLA at 324.5MHz
covering a region of the SWIRE Spitzer Legacy survey, centered at
10:46:00, +59:01:00 (J2000). The data reduction and analysis are
described and an electronic catalog of the sources detected above
5σ is presented. We also discuss the observed angular size
distribution for the sample. Using our deeper 20cm survey of the same
field, we calculate spectral indices for sources detected in both
surveys.
Description:
Observations were made of a single pointing center position, with the
VLA in A and C configurations for a total of almost 85hr on-source
between 2006 February and 2007 January.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 80 1436 Radio source catalog
table4.dat 47 229 Spectral indices for 90cm selected sources
table6.dat 17 369 Spectral indices for 20cm selected sources
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See also:
J/AJ/136/1889 : The deep SWIRE field I. (Owen+, 2008)
J/ApJS/182/625 : The deep SWIRE field III. (Owen+, 2009)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 ---- [OMK2009] Catalog Source Number (1)
7- 8 I2 h RAh Hour of Right Ascension (J2000)
10- 11 I2 min RAm Minutes of Right Ascension (J2000)
13- 17 F5.2 s RAs Seconds of Right Ascension (J2000)
19- 22 F4.2 s e_RAs Error in RAs
23 A1 --- DE- Sign of Declination (J2000)
24- 25 I2 deg DEd Degrees of Declination (J2000)
27- 28 I2 arcmin DEm Arcminute of Declination (J2000)
30- 33 F4.1 arcsec DEs Arcsecond of Declination (J2000)
35- 37 F3.1 arcsec e_DEs Error in DEs
39- 44 I6 uJy Speak Observed peak brightness at 324.5MHz
(uJy/beam)
47- 53 I7 uJy Stot Total Flux Density at 324.5MHz
55- 59 I5 uJy e_Stot Error in Stotal
62- 67 F6.1 --- S/N Peak Signal/Noise ratio
69 A1 --- l_bmaj [< ] Limit flag for size
71- 73 I3 arcsec bmaj Fitted Gaussian major axis FWHM (2)
75- 76 I2 arcsec bmin ? Fitted Gaussian minor axis FWHM (3)
78- 80 I3 deg PA ? Fitted position angle
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Note (1): If the source has a number less than 3000, then it was found
with an S/N≥5.0 from running SAD on the full resolution image.
Sources with numbers ≥10000 were found in lower resolution images
or in checks of the residual images. Numbers beginning with 12 were
measured on a 12" resolution image. If the number begins with 24 then
we used a 24" resolution image.
Note (2): Or the maximum size for very large sources.
Note (3): When the minor axis is unresolved, we give "0" as the minor axis
size in the table and assume a one-dimensional Gaussian size when
estimating the total flux density.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- [OMK2009] 90cm radio source name (324.5MHz)
7- 11 F5.2 --- alpha 90cm-20cm spectral index;
(S∝ν-α)
13- 16 F4.2 --- e_alpha Error in alpha
19- 23 I5 uJy S90 Measured 90cm flux density
25- 31 F7.1 uJy S20 Measured 20cm flux density
33 A1 --- f_size90 [<r] 90cm size limit flag (1)
35- 37 I3 arcsec size90 90cm source size or upper limit
39 A1 --- f_size20 [<r] 20cm size limit flag (1)
41- 45 F5.1 arcsec size20 20cm Source size or upper limit
47 A1 --- n_alpha [* ] Note on spectral index α (2)
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Note (1): Flags as follows:
< = upper limit in size column.
r = deconvolved major axis in size column.
Note (2):
* = Spectral index determined from peak of equal resolution images
at 20cm and 90cm.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- [OM2008] 20cm Catalog Source Number from paper I
7 A1 --- l_alpha [<] Limit flag on alpha
8- 12 F5.2 --- alpha 90cm-20cm spectral index;
S∝ν-α
14- 17 F4.2 --- e_alpha ? Error on alpha
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History:
From electronic version of the journal
References:
Owen F.N.+, Paper I. 2008AJ....136.1889O 2008AJ....136.1889O, Cat. J/AJ/136/1889
Owen F.N.+, Paper III. 2009ApJS..182..625O 2009ApJS..182..625O, Cat. J/AJ/182/625
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 18-Jan-2010