J/AJ/144/150 QCAL-1 43 GHz Calibrator Survey (Petrov+, 2012)
Early science with the Korean VLBI Network: the QCAL-1 43 GHz Calibrator Survey.
Petrov L., Lee S.-S., Kim J., Jung T., Oh J., Sohn B.W., Byun D.-Y.,
Chung M.-H., Je D.-H., Wi S.-O., Song M.-G., Kang J., Han S.-T., Lee J.-W.,
Kim B.G., Chung H., Kim H.-G.
<Astron. J., 144, 150 (2012)>
=2012AJ....144..150P 2012AJ....144..150P
ADC_Keywords: VLBI ; Radio sources ; Surveys ; Interferometry
Keywords: astrometry - galaxies: active - radio continuum: galaxies - surveys -
techniques: interferometric
Abstract:
This paper presents the catalog of correlated flux densities in three
ranges of baseline projection lengths of 637 sources from a 43GHz (Q
band) survey observed with the Korean VLBI Network. Of them, 14
objects used as calibrators were previously observed, but 623 sources
have not been observed before in the Q band with very long baseline
interferometry (VLBI). The goal of this work in the early science
phase of the new VLBI array is twofold: to evaluate the performance of
the new instrument that operates in a frequency range of 22-129GHz and
to build a list of objects that can be used as targets and as
calibrators. We have observed the list of 799 target sources with
declinations down to -40°. Among them, 724 were observed before
with VLBI at 22GHz and had correlated flux densities greater than
200mJy. The overall detection rate is 78%. The detection limit,
defined as the minimum flux density for a source to be detected with
90% probability in a single observation, was in the range of
115-180mJy depending on declination. However, some sources as weak as
70mJy have been detected. Of 623 detected sources, 33 objects are
detected for the first time in VLBI mode. We determined their
coordinates with a median formal uncertainty of 20mas. The results of
this work set the basis for future efforts to build the complete
flux-limited sample of extragalactic sources at frequencies of 22GHz
and higher at 3/4 of the celestial sphere.
Description:
The Korean VLBI Network (KVN) is the first dedicated Very Long
Baseline Interferometry (VLBI) network in East Asia in millimeter
wavelengths. The KVN was built by Korea Astronomy and Space Science
Institute (KASI). The KVN consists of three 21m radio telescopes: in
Seoul, the KVN Yonsei Radio Telescope (KVNYS); in Ulsan, the KVN Ulsan
Radio Telescope (KVNUS); and on Jeju island, Korea, the KVN Tamna
Radio Telescope (KVNTN). The antennas are equipped with a quasi-optic
system that allows simultaneous observations at 22, 43, 86, and
129GHz. In this paper, we present results of the 43GHz VLBI survey
conducted at the three-element KVN radio interferometer. We observed
target sources in three observing sessions in 2011 December 18, 19,
and 22.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 95 637 Catalog of correlated flux densities of 637 sources
that have at least 3 detections in Korean VLBI
Network (KVN) QCAL-1 observing campaign
table4.dat 68 33 QCAL-1 catalog of positions of the 33 sources never
observed before with VLBI
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See also:
J/AJ/143/35 : KCAL VERA 22 GHz calibrator survey (Petrov+, 2012)
J/MNRAS/419/1097 : The EVN Galactic Plane Survey - EGaPS (Petrov, 2012)
J/AJ/142/35 : The VLBA Galactic Plane Survey (VGaPS) (Petrov+, 2011)
J/ApJS/194/29 : Observations of blazars at 15GHz (Richards+, 2011)
J/AJ/139/1695 : Celestial Reference Frame at 24 and 43 GHz (Lanyi+, 2010)
J/MNRAS/402/2403 : Australia Telescope 20GHz Survey Catalog (Murphy+, 2010)
J/AJ/136/580 : Sixth VLBA calibrator survey: VCS6 (Petrov+, 2008)
J/AJ/133/2487 : VERA 22GHz Fringe Search Survey (Petrov+, 2007)
J/AJ/133/1236 : Fifth VLBA calibrator survey: VCS5 (Kovalev+, 2007)
J/AJ/131/1872 : Fourth VLBA calibrator survey: VCS4 (Petrov+, 2006)
J/AJ/129/1163 : Third VLBA calibrator survey: VCS3 (Petrov+, 2005)
J/AJ/126/2562 : Second VLBA calibrator survey: VCS2 (Fomalont+, 2003)
J/ApJS/141/13 : VLBA calibrator survey: VCS1 catalog (Beasley+, 2002)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- JName The IAU J2000.0 source name (JHHMM+DDMM)
12- 19 A8 --- BName The IVS B1950.0 source name (HHMM+DDd)
in Simbad
21 A1 --- T [CN] Source type (Calibrator or New) (1)
23- 24 I2 --- N [2/48] Number of observations source detected
26- 31 F6.3 Jy F1 ?=-1 Median correlated 43GHz flux density at
baseline projection lengths <21.44 Mλ
33- 38 F6.3 Jy F2 ?=-1 Median correlated 43GHz flux density at
baseline projection lengths 21.44-42.88 Mλ
40- 45 F6.3 Jy F3 ?=-1 Median correlated 43GHz flux density at
baseline projection lengths >42.88 Mλ
47- 52 F6.3 Jy e_F1 ?=-1 Mean error in F1
54- 59 F6.3 Jy e_F2 ?=-1 Mean error in F2
61- 66 F6.3 Jy e_F3 ?=-1 Mean error in F3
69- 70 I2 h RAh Hour of Right Ascension (J2000)
72- 73 I2 min RAm Minute of Right Ascension (J2000)
75- 81 F7.4 s RAs Second of Right Ascension (J2000)
83 A1 --- DE- Sign of the Declination (J2000)
84- 85 I2 deg DEd Degree of Declination (J2000)
87- 88 I2 arcmin DEm Arcminute of Declination (J2000)
90- 95 F6.3 arcsec DEs Arcsecond of Declination (J2000)
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Note (1): Type of source as follows:
N = New source never been observed with Very Long Baseline Interferometry
(VLBI) before;
C = An amplitude calibrator.
blank = target source observed before with Very Long Baseline Interferometry
(VLBI) at other frequencies)
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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- 10 A10 --- JName The IAU J2000.0 source name (JHHMM+DDMM)
12- 19 A8 --- BName The IVS B1950.0 source name (HHMM+DDd)
21- 22 I2 h RAh Hour of Right Ascension (J2000)
24- 25 I2 min RAm Minute of Right Ascension (J2000)
27- 33 F7.4 s RAs Second of Right Ascension (J2000)
35 A1 --- DE- Sign of the Declination (J2000)
36- 37 I2 deg DEd Degree of Declination (J2000)
39- 40 I2 arcmin DEm Arcminute of Declination (J2000)
42- 47 F6.3 arcsec DEs Arcsecond of Declination (J2000)
49- 52 F4.1 mas e_RAs Error in right ascension without scaling
factor cosδ
54- 57 F4.1 mas e_DEs Error in declination
59- 64 F6.3 --- Corr [-1/1] Correlation between estimates of right
ascension and declination
66 I1 --- N1 [3/6] Number of observations source detected
68 I1 --- N2 [1/2] Number of experiments source detected
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 16-Dec-2013