J/MNRAS/457/1496 10C cont.: a deeper radio survey at 15.7GHz (Whittam+, 2016)
10C continued: a deeper radio survey at 15.7 GHz.
Whittam I.H., Riley J.M., Green D.A., Davies M.L., Franzen T.M.O.,
Rumsey C., Schammel M.P., Waldram E.M.
<Mon. Not. R. Astron. Soc. 457, 1496 (2016)>
=2016MNRAS.457.1496W 2016MNRAS.457.1496W (SIMBAD/NED BibCode)
ADC_Keywords: Radio sources ; Surveys ; Radio continuum
Keywords: catalogues - surveys - galaxies: active - radio continuum: galaxies
Abstract:
We present deep 15.7-GHz observations made with the Arcminute
Microkelvin Imager (AMI) Large Array in two fields previously observed
as part of the Tenth Cambridge (10C) survey. These observations allow
the source counts to be calculated down to 0.1mJy, a factor of five
deeper than achieved by the 10C survey. The new source counts are
consistent with the extrapolated fit to the 10C source count, and
display no evidence for either steepening or flattening of the counts.
There is thus no evidence for the emergence of a significant new
population of sources (e.g. starforming) at 15.7GHz flux densities
above 0.1mJy, the flux density level at which we expect starforming
galaxies to begin to contribute. Comparisons with the de Zotti et al.
model and the SKADS Simulated Sky show that they both underestimate
the observed number of sources by a factor of two at this flux density
level. We suggest that this is due to the flat-spectrum cores of radio
galaxies contributing more significantly to the counts than predicted
by the models.
Description:
The 10C survey of radio sources has been made with the Arcminute
Microkelvin Imager (AMI) Large Array at 15.7GHz and a resolution of
approximately 30-arcsec (AMI Consortium: Davies et al., 2011, Cat.
J/MNRAS/415/2708, AMI Consortium: Franzen et al. 2011MNRAS.415.2699F 2011MNRAS.415.2699F).
New, deeper observations have been made in two of the 10C fields: the
AMI001 field (J0024+3152) and the Lockman Hole field (J1052+5730).
These new observations have been combined with the existing 10C
observations to produce deeper source catalogues in both fields. Note
that the noise varies significantly across the fields (see paper for
details). The catalogue contains a total of 495 sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
10c_cont.dat 132 495 The extended 10C source list for the
Lockman Hole and AMI001 fields
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See also:
J/MNRAS/415/2708 : 10C survey of radio sources at 15.7GHz (Davies+, 2011)
Byte-by-byte Description of file: 10c_cont.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- ID Source designation (JHHMMSS+DDMMSS)
16- 28 A13 --- Group Group designation (HHMMSS+DDMMSS)
29 A1 --- --- [(]
30- 31 I2 --- N ? Number of components in group
32 A1 --- --- [)]
34- 35 I2 h RAh Peak right ascension (J2000)
37- 38 I2 min RAm Peak right ascension (J2000)
40- 44 F5.2 s RAs Peak right ascension (J2000)
46 A1 --- DE- Peak declination sign (J2000)
47- 48 I2 deg DEd Peak declination (J2000)
50- 51 I2 arcmin DEm Peak declination (J2000)
53- 57 F5.2 arcsec DEs Peak declination (J2000)
59- 64 F6.3 mJy Spk Peak flux density at 15.7GHz
66- 70 F5.3 mJy e_Spk Error on peak flux density
72- 73 I2 h RAIh ? Centroid right ascension (J2000) (1)
75- 76 I2 min RAIm ? Centroid right ascension (J2000) (1)
78- 82 F5.2 s RAIs ? Centroid right ascension (J2000) (1)
84 A1 --- DEI- ? Centroid declination sign (J2000) (1)
85- 86 I2 deg DEId ? Centroid declination (J2000) (1)
88- 89 I2 arcmin DEIm ? Centroid declination (J2000) (1)
91- 95 F5.2 arcsec DEIs ? Centroid declination (J2000) (1)
97-102 F6.3 mJy Sint ? Integrated flux density at 15.7GHz
103-108 F6.3 mJy e_Sint ? Error on integrated flux density
110-113 F4.1 arcsec eCrit ? Critical value of the major axis (2)
115-119 F5.1 arcsec eMaj ? Major axis after deconvolution
121-124 F4.1 arcsec eMin ? Minor axis after deconvolution
126-130 F5.1 deg PA ? Position angle of major axis
132 A1 --- t [PE-] Point or Extended source (3)
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Note (1): relevant for extended sources
Note (2): the critical value of the major axis ecrit id the value above
which the source is defined as extended.
Note (3): Source type as follows:
P = point source
E = extended source
- = fitting failed, unclassified
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Acknowledgements:
Imogen Whittam, imogenwhittam(at)gmail.com
References:
Franzen et al., Paper I 2011MNRAS.415.2699F 2011MNRAS.415.2699F
Davies et al., Paper II 2011MNRAS.415.2708D 2011MNRAS.415.2708D, Cat. J/MNRAS/415/2708
(End) Imogen Whittam [UWC], Patricia Vannier [CDS] 09-Feb-2016