J/AJ/142/105 Optically Bright Extragalactic Radio Sources (Petrov+, 2011)
The catalog of positions of optically bright extragalactic radio sources OBRS-1
Petrov L.
<Astron. J., 142, 105 (2011)>
=2011AJ....142..105P 2011AJ....142..105P
ADC_Keywords: VLBI ; Radio sources
Keywords: catalogs ; surveys ; interferometry
Abstract:
It is expected that the European Space Agency mission Gaia will make
possible to determine coordinates in the optical domain of more than
500,000 quasars. In 2006, a radio astrometry project was launched with
the overall goal to make comparison of coordinate systems derived from
future space-born astrometry instruments with the coordinate system
constructed from analysis of the global very long baseline
interferometry (VLBI) more robust. Investigation of their rotation,
zonal errors, and the non-alignment of the radio and optical positions
caused by both radio and optical structures are important for
validation of both techniques. In order to support these studies, the
densification of the list of compact extragalactic objects that are
bright in both radio and optical ranges is desirable. A set of 105
objects from the list of 398 compact extragalactic radio sources with
declinations >-10° was observed with the VLBA+EVN with the
primary goal of producing their images with milliarcsecond resolution.
These sources are brighter than 18 magnitude at V band, and they were
previously detected at the European VLBI network. In this paper
coordinates of observed sources have been derived with milliarcsecond
accuracies from analysis of these VLBI observations following the
method of absolute astrometry. The catalog of positions of 105 target
sources is presented. The accuracies of sources coordinates are in the
range of 0.3 to 7mas, with the median 1.1mas.
Description:
The OBRS1 catalog presents precise positions of 105 compact
extragalactic radio sources as well as median correlated flux
densities at 8.6 and 2.3GHz at baseline lengths shorter than 900km and
at baseline lengths longer than 5000km.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 99 105 OBRS1 catalog of source positions and
correlated flux densities at X and S bands
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See also:
I/251 : VLBI International Celestial Reference Frame ICRF (Ma+ 1997)
J/A+A/437/1135 : Near-IR astrometry of Southern ICRF quasars (Camargo+, 2005)
J/A+A/493/317 : Radio source selection for the ICRF (Lambert+, 2009)
J/A+A/520/A113 : 398 extragal. radio sources VLBI detection (Bourda+ 2010)
J/AJ/125/2728 : Optical positions of ICRF sources (Assafin+, 2003)
J/AJ/127/3587 : VLBI ICRF. II (Fey+, 2004)
J/AJ/127/3609 : VLBI observations of southern ICRF sources (Ojha+, 2004)
J/AJ/130/2529 : Southern ICRF sources 8.4GHz VLBI observations (Ojha+, 2005)
J/MNRAS/416/1097 : The EVN Galactic Plane Survey - EGaPS (Petrov, 2012)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- IVS IVS name (International VLBI Service for
geodesy and Astrometry; based on B1950 position)
10- 19 A10 --- IAU IAU name (based on J2000 position)
21- 22 I2 h RAh Hour of Right Ascension (J2000)
24- 25 I2 min RAm Minute of Right Ascension (J2000)
27- 35 F9.6 s RAs Second of Right Ascension (J2000)
37 A1 --- DE- Sign of the Declination (J2000)
38- 39 I2 deg DEd Degree of Declination (J2000)
41- 42 I2 arcmin DEm Arcminute of Declination (J2000)
44- 51 F8.5 arcsec DEs Arcsecond of Declination (J2000)
53- 56 F4.2 mas e_RAs Uncertainty in RAs; without cosδ factor
58- 61 F4.2 mas e_DEs Uncertainty in DEs
63- 68 F6.3 --- Corr [-1,+1] Correlation between RA and Dec
70- 72 I3 --- Nobs Number of observations used
74- 78 F5.3 Jy F(S)s S-band (2.3GHz) "short" flux density (1)
80- 84 F5.3 Jy F(S)l S-band (2.3GHz) "long" flux density (1)
86- 90 F5.3 Jy F(X)s X-band (8.6GHz) "short" flux density (1)
92- 96 F5.3 Jy F(X)l X-band (8.6GHz) "long" flux density (1)
98- 99 A2 --- Flag [VX ] Cross-reference flag (2)
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Note (1):
short = at baseline projection lengths shorter than 900km.
long = at baseline projection lengths longer than 5000km.
Note (2): Flag as follows:
V = a source was observed in VIPS campaign (VLBA Imaging and
Polarimetry) at 5GHz;
X = a source was observed in RDV or VCS (VLBA Calibrator Survey)
experiments at 2.3 and 8.6GHz;
VX = a source was observed in both 5GHz and 2.3/8.6GHz.
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Acknowledgements:
Catalog originally prepared by L. Petrov, Leonid.Petrov(at)lpetrov.net
(End) Francois Ochsenbein [CDS] 10-Mar-2012