J/ApJS/230/13 VLBI Ecliptic Plane Survey: VEPS-1 (Shu+, 2017)
VLBI Ecliptic Plane Survey: VEPS-1.
Shu F., Petrov L., Jiang W., Xia B., Jiang T., Cui Y., Takefuji K.,
McCallum J., Lovell J., Yi S.-O., Hao L., Yang W., Zhang H., Chen Z., Li J.
<Astrophys. J. Suppl. Ser., 230, 13-13 (2017)>
=2017ApJS..230...13S 2017ApJS..230...13S (SIMBAD/NED BibCode)
ADC_Keywords: Interferometry ; Radio sources ; Surveys ; VLBI ; Positional data
Keywords: astrometry; catalogs; reference systems; surveys;
techniques: interferometric
Abstract:
We present here the results of the first part of the VLBI Ecliptic
Plane Survey (VEPS) program. The goal of the program is to find all
compact sources within 7.5° of the ecliptic plane that are
suitable as calibrators for anticipated phase referencing observations
of spacecraft, and determine their positions with accuracy at the
1.5 nrad level. We run the program in two modes: search and refine. In
the search mode, a complete sample of all sources brighter than 50mJy
at 5GHz listed in the Parkes-MIT-NRAO and Green Bank 6cm (GB6)
catalogs, except those previously detected with VLBI, is observed. In
the refining mode, the positions of all ecliptic plane sources,
including those found in the search mode, are improved. By 2016
October, thirteen 24hr sessions that targeted all sources brighter
than 100mJy have been observed and analyzed. Among 3320 observed
target sources, 555 objects have been detected. We also conducted a
number of follow-up VLBI experiments in the refining mode and improved
the positions of 249 ecliptic plane sources.
Description:
We began observations in the search mode in 2015 February. The
participating stations included the three core stations of the Chinese
VLBI Network (CVN): seshan25, kunming, and urumqi. Depending on the
participating stations, the longest baseline length in each session
can be varied from 3200km to 9800km.
Our observations were performed at a 2048Mbps data rate, with 16
Intermediate Frequency (IF) channels and 2-bit sampling. The first
eight IFs of 32MHz bandwidth were distributed in the range of [8.188,
8.444]GHz, and the remaining eight IFs of 32MHz bandwidth were in the
range of [8.700, 8.956]GHz.
Table 1: Summary of the VLBI Ecliptic Plane Survey (VEPS) observations
in search mode:
---------------------------------------------------
Date Dur. Code Stations Number of
(Y/M/D) (h) Targets
---------------------------------------------------
2015 Feb 13 24 VEPS01 ShKmUr 293
2015 Feb 14 24 VEPS02 ShKmUr 338
2015 Apr 23 24 VEPS03 UrKv 300
2015 Apr 24 24 VEPS04 ShKmUrKv 400
2015 Aug 10 25 VEPS05 ShKmKvHo 252
2015 Aug 19 25 VEPS06 ShKmKvHo 277
2016 Mar 02 24 VEPS07 ShKmUrKb 333
2016 Mar 11 24 VEPS08 ShKmUrKb 477
2016 May 13 24 VEPS09 ShUrHo 291
2016 May 14 22 VEPS10 ShUrKv 322
2016 Jul 06 24 VEPS11 ShUrKb 307
2016 Sep 02 23 VEPS12 ShUr 424
2016 Sep 03 23 VEPS13 ShKmUr 344
---------------------------------------------------
Sh=Seshan25; Km=Kunming; Ur=Urumqi; Kv=Sejong;
Kb=Kashim34; Ho=Hobart26.
---------------------------------------------------
We ran two absolute astrometry dual-band VLBA programs that targeted
ecliptic plane compact radio sources: the dedicated survey of weak
ecliptic plane calibrators with the VLBA BS250 program in 2016
March-May, and the VLBA Calibrator Survey 9 (VCS-9) in 2015
August-2016 September.
The International VLBI Service for Geodesy and Astrometry (IVS) runs a
number of VLBI observing programs. We made an attempt to improve the
coordinates of some VEPS sources detected in the search mode and
provide additional measurements of telescope position with the same
experiments in two such 24hr sessions, AOV010 in July and AUA012 in
2016 August.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 88 555 The 555 target sources detected in the search
mode of the survey
table3.dat 121 249 The 249 sources observed in the refining mode
of the survey
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See also:
VIII/38 : The Parkes-MIT-NRAO 4.85GHz (PMN) Surveys (Griffith+ 1993-1996)
VIII/40 : GB6 catalog of radio sources (Gregory+ 1996)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/other/BSAO/46.28 : Complete sample of PMN survey spectra (Mingaliev+, 1998)
J/ApJS/141/13 : VLBA calibrator survey: VCS1 catalog (Beasley+, 2002)
J/AJ/126/2562 : Second VLBA calibrator survey: VCS2 (Fomalont+, 2003)
J/AJ/129/1163 : Third VLBA calibrator survey: VCS3 (Petrov+, 2005)
J/AJ/131/1872 : Fourth VLBA calibrator survey: VCS4 (Petrov+, 2006)
J/AJ/133/1236 : Fifth VLBA calibrator survey: VCS5 (Kovalev+, 2007)
J/AJ/136/580 : Sixth VLBA calibrator survey: VCS6 (Petrov+, 2008)
J/ApJS/194/25 : The VLBA calibrator search for the BeSSeL survey (Immer+, 2011)
J/AJ/142/105 : Optically Bright Extragalactic Radio Sources (Petrov+, 2011)
J/AJ/142/35 : The VLBA Galactic Plane Survey (VGaPS) (Petrov+, 2011)
J/MNRAS/414/2528 : LBA Calibrator Survey (LCS1) (Petrov+, 2011)
J/AJ/142/89 : Precise astrometry with VLBA (VIPS) (Petrov+, 2011)
J/MNRAS/419/1097 : The EVN Galactic Plane Survey - EGaPS (Petrov, 2012)
J/MNRAS/422/1527 : Australia Telescope PMN follow-up survey (McConnell+, 2012)
J/AJ/144/150 : QCAL-1 43 GHz Calibrator Survey (Petrov+, 2012)
J/AJ/146/5 : Optically Bright extragalactic Radio Sources II (Petrov, 2013)
J/ApJS/217/4 : 2FGL sources observed between 5-9GHz (Schinzel+, 2015)
J/AJ/151/154 : Second epoch VLBA Calibrator Survey (VCS-II) (Gordon+, 2016)
J/AJ/151/79 : Radio fluxes of ICRF2-Gaia transfer sources (Le Bail+, 2016)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Ff [BIV ] Follow-up flag (G1)
4- 11 A8 --- BName B1950 source name
13- 22 A10 --- JName J2000 source name
25- 26 I2 h RAh Hour of Right Ascension (J2000)
28- 29 I2 min RAm Minute of Right Ascension (J2000)
31- 39 F9.6 s RAs Second of Right Ascension (J2000)
41 A1 --- DE- Sign of the Declination (J2000)
42- 43 I2 deg DEd Degree of Declination (J2000)
45- 46 I2 arcmin DEm Arcminute of Declination (J2000)
48- 55 F8.5 arcsec DEs Arcsecond of Declination (J2000)
57- 62 F6.2 mas e_RAs [0.6/39] Uncertainty in RAs; without cos(delta)
factor
64- 69 F6.2 mas e_DEs [0.3/130] Uncertainty in DEs
71- 76 F6.3 --- Corr Correlation between RA and DEC estimates
79- 81 I3 --- Nobs [2/20] Number of observations used in the solution
84- 88 F5.3 Jy Flux [0.01/0.4] Median flux density at 8.5GHz
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Ff [BIV] Follow-up flag (G1)
4- 11 A8 --- BName B1950 source name
13- 22 A10 --- JName J2000 source name
25- 26 I2 h RAh Hour of Right Ascension (J2000)
28- 29 I2 min RAm Minute of Right Ascension (J2000)
31- 39 F9.6 s RAs Second of Right Ascension (J2000)
41 A1 --- DE- Sign of the Declination (J2000)
42- 43 I2 deg DEd Degree of Declination (J2000)
45- 46 I2 arcmin DEm Arcminute of Declination (J2000)
48- 55 F8.5 arcsec DEs Arcsecond of Declination (J2000)
57- 62 F6.2 mas e_RAs [0.1/15] Uncertainty in RAs; without cos(delta)
factor
64- 69 F6.2 mas e_DEs [0.1/48] Uncertainty in DEs
71- 76 F6.3 --- Corr Correlation between RA and DEC estimates
78- 81 I4 --- Nobs [3/1166] Number of observations used in the
solution
84- 88 F5.3 Jy TFlX [0.01/2.7] Total flux density at 8GHz (1)
90- 94 F5.3 Jy UFlX [0.009/1.3] Unresolved flux density at 8GHz (2)
97-101 F5.3 Jy TFlS [0.02/2.8]? Total flux density at 4.4GHz (1)
103-107 F5.3 Jy UFlS [0.01/1.1]? Unresolved flux density at 4.4GHz (2)
110-114 F5.3 Jy TFlC [0.02/2.1]? Total flux density at 2.3GHz (1)
116 A1 --- l_UFlC Limit flag on UFlC
117-121 F5.3 Jy UFlC [0.02/1.3]? Unresolved flux density at 2.3GHz (2)
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Note (1): Integrated over image.
Note (2): Median flux density at baseline projection length longer than 5000km.
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Global notes:
Note (G1): Follow-up flag as follows:
V = the VLBA Calibrator Survey 9 (VCS-9) in 2015 August-2016 September;
see section 3.2.
B = the VLBA BS250 program in 2016 March-May; see section 3.2.
I = the International VLBI Service for Geodesy and Astrometry (IVS) network;
see section 3.3.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Aug-2017