J/MNRAS/502/4779 28-40GHz variability and polarimetry (Perrott+, 2021)
28-40 GHz variability and polarimetry of bright compact sources in the
QUIJOTE cosmological fields.
Perrott Y.C., Lopez-Caniego M., Genova-Santos R.T., Rubino-Martin J.A.,
Ashdown M., Herranz D., Lahteenmaki A., Lasenby A.N., Lopez-Caraballo C.H.,
Poidevin F., Tornikoski M.
<Mon. Not. R. Astron. Soc. 502, 4779-4793 (2021)>
=2021MNRAS.502.4779P 2021MNRAS.502.4779P (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Interferometry ; Polarization ;
Radio continuum ; Radio sources
Keywords: quasars: general - cosmic background radiation -
cosmology: observations - radio continuum: general
Abstract:
We observed 51 sources in the Q-U-I JOint TEnerife (QUIJOTE)
cosmological fields which were brighter than 1Jy at 30GHz in the
Planck Point Source Catalogue (version 1), with the Very Large Array
at 28-40GHz, in order to characterise their high-radio-frequency
variability and polarization properties. We find a roughly log-normal
distribution of polarization fractions with a median of 2%, in
agreement with previous studies, and a median rotation measure (RM) of
∼1110rad/m2 with one outlier up to ∼64000rad/m2 which is among the
highest RMs measured in quasar cores. We find hints of a correlation
between the total intensity flux density and median polarization
fraction. We find 59% of sources are variable in total intensity, and
100% in polarization at 3σ level, with no apparent correlation
between total intensity variability and polarization variability. This
indicates that it will be difficult to model these sources without
simultaneous polarimetric monitoring observations and they will need
to be masked for cosmological analysis.
Description:
The 51 sources were observed with the VLA with two frequency bands spanning
28.5-32.4 and 35.5-39.4GHz. 41 of the sources had two epochs of
observation. The measurements quoted are for the compact core of the
sources, which dominated and was not resolved in all cases except for
PCCS1 030 G157.08-42.72 and PCCS1 030 G147.84-44.04, which contain a
contribution from the extended source structure. The observations were
taken in VLA configuration B or C with approximate beam sizes of 0.3
and 1.0 arcsec respectively. Spectral fits were made across the two
bands and the values of the fitting parameters quoted in the table,
where the central frequency is 34GHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 150 92 28-40GHz variability and polarimetry
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See also:
VIII/91 : Planck Catalog of Compact Sources Release 1 (Planck, 2013)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 13 A13 deg Name1 PCCS1 30GHz catalogue name, GLLL.ll+BB.bb
15- 27 A13 deg Name2 PCCS2 30GHz catalogue name, GLLL.ll+BB.bb
29- 30 I2 h RAh Right Ascension (J2000)
32- 33 I2 min RAm Right Ascension (J2000)
35- 39 F5.2 s RAs Right Ascension (J2000)
41 A1 --- DE- Declination sign (J2000)
42- 43 I2 deg DEd Declination (J2000)
45- 46 I2 arcmin DEm Declination (J2000)
48- 52 F5.2 arcsec DEs Declination (J2000)
54- 64 F11.5 d Epoch Observation MJD
66- 72 F7.4 Jy S0 Flux density at central frequency 34GHz
74- 79 F6.4 Jy e_S0 Error in central flux density
81- 86 F6.3 --- Sp+Index Spectral index
88- 92 F5.3 --- e_Sp+Index Error in spectral index
94-100 F7.5 --- P0 ? Polarization fraction at central
frequency 34GHz.
102-108 F7.5 --- e_P0 ? Error in central polarization fraction
110-115 F6.3 --- Sp+IndexP ? Spectral index in polarization fraction
117-121 F5.3 --- e_Sp+IndexP ? Error in polarisation fraction spectral
index
123-128 F6.2 deg Phi0 ? Polarization angle at central
frequency 34GHz
130-134 F5.2 deg e_Phi0 ? Error in central polarization angle
136-143 F8.1 rad/m2 RM ? Rotation measure
145-150 F6.1 rad/m2 e_RM ? Error in rotation measure
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Acknowledgements:
Yvette Perrott, yvette.perrott(at)vuw.ac.nz
(End) Patricia Vannier [CDS] 02-Feb-2021