J/AJ/166/8 Radio-optical Reference Catalog, Version 1 (RORC-1) (Makarov+, 2023)
Radio-optical Reference Catalog, Version 1.
Makarov V.V., Johnson M.C., Secrest N.J.
<Astron. J., 166, 8 (2023)>
=2023AJ....166....8M 2023AJ....166....8M
ADC_Keywords: Radio sources; Optical; Cross identifications
Keywords: Astrometry ; Astronomical coordinate systems ; Very long
baseline interferometry ; Radio-loud quasars ; Gaia
Abstract:
The fundamental celestial reference frame (CRF) is based on two
catalogs of astrometric positions: the third realization of the
International Celestial Reference Frame (ICRF3), and the much larger
Gaia CRF, built from the third data release (DR3). The objects in
common between these two catalogs are mostly distant AGNs and quasars
that are both sufficiently optically bright for Gaia and radio loud
for the VLBI. This limited collection of reference objects is
crucially important for the mutual alignment of the two CRFs and the
maintenance of all of the other frames and coordinate systems
branching from the ICRF. In this paper, we show that the three
components of ICRF3 (S/X, K, and X/Ka band catalogs) have
significantly different sky-correlated vector fields of position
offsets with respect to Gaia DR3. When iteratively expanded in the
vector spherical harmonics up to degree 4 on a carefully vetted set of
common sources, each of these components includes several
statistically significant terms. The median sky-correlated offsets
from the Gaia positions are found to be 56µas for the S/X,
100µas for the K, and 324µas for the X/Ka catalogs. The weighted
mean vector field is subtracted from the Gaia reference positions,
while the deviations from that field are added to each of the ICRF3
components. The corrected positions from each of the four input
catalogs are combined into a single weighted mean catalog, which we
propose to be the current most accurate realization of an inertial
radio-optical CRF.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 91 2284 Radio-Optical Reference Catalog -- 1
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See also:
I/323 : International Celestial Reference Frame 2, ICRF2 (Ma+, 2009)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/AJ/150/58 : VLBI ICRF2 (Fey+, 2015)
J/ApJ/835/L30 : Dislodged AGNs (Makarov+, 2017)
J/MNRAS/475/5179 : Spatially offset AGN cand. in CLASS survey (Skipper+, 2018)
J/A+A/622/A165 : Gaia GraL. III. New lensed systems (Delchambre+, 2019)
J/A+A/630/A101 : Multi-frequency celestial reference frame (Karbon+, 2019)
J/ApJ/873/132 : ICRF3 radio-loud quasars with Gaia DR2 data (Makarov+, 2019)
J/ApJS/242/5 : 40yr geodetic/astrometric VLBI obs ICRF sources (Xu+, 2019)
J/A+A/644/A159 : The third realization of the ICRF, ICRF3 (Charlot+, 2020)
J/ApJS/260/33 : PropertiesICRF3 sources from SDSS spectra (Sexton+, 2022)
J/A+A/660/A16 : Quasars with large proper motions (Souchay+, 2022)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- ICRF ICRF position-based name
18- 36 I19 --- Gaia Gaia DR3 identifier
38- 51 F14.10 deg RAdeg [0/360] Right Ascension, derived RORC position
(J2000)
53- 66 F14.10 deg DEdeg [-86/87] Declination, derived RORC position
(J2000)
68- 71 I4 --- eRAdeg [12/1056] Formal uncertainty in RAdeg,
µarcseconds
73- 76 I4 --- eDEdeg [10/1138] Formal uncertainty in DEdeg,
µarcseconds
78- 83 F6.3 --- rho [-0.79/0.69] RA-declination correlation
85- 85 I1 --- f_Gaia [1] Gaia DR3 catalog flag (1)
87- 87 I1 --- S/X [0/1] ICRF3 S/X band frame catalog flag (1)
89- 89 I1 --- K [0/1] ICRF3 K band frame catalog flag (1)
91- 91 I1 --- Ka [0/1] ICRF3 Ka band frame catalog flag (1)
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Note (1): 0 if not available, 1 if available.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 29-Jan-2024