J/MNRAS/430/2633 The epoch ICRF (Xu+, 2013)
A new concept of the International Celestial Reference Frame: the epoch ICRF.
Xu M.H., Wang G.L., Zhao M.
<Mon. Not. R. Astron. Soc., 430, 2633-2637 (2013)>
=2013MNRAS.430.2633X 2013MNRAS.430.2633X
ADC_Keywords: Fundamental catalog ; Positional data ; VLBI
Keywords: astrometry - proper motions - reference systems
Abstract:
The epoch International Celestial Reference Frame (epoch ICRF) is
proposed as a new concept in order to consider the effect of apparent
proper motion of the position of a radio source due to acceleration of
the spatial origin of the ICRF, the centre of mass of the Solar
system. This apparent proper motion has a magnitude of approximately
5.8-microarcsec (µas) per year, and for the 30-year very long
baseline interferometry (VLBI) observational history these position
variations will exceed 100µas. We show that the dipole structure
of the apparent proper motions leads to global rotation in the ICRF2
and the main term, the shift of direction of the origin of right
ascension, reaches 25µas per century. The 'epoch ICRF' is
constructed using epoch positions at J2000.0 and apparent proper
motions of radio sources, which are reported here for 295
ICRF2-defining sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 67 295 Coordinates at J2000.0 and apparent proper
motions of 295 ICRF2 defining sources
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See also:
I/323 : International Celestial Reference Frame 2, ICRF2 (Ma+, 2009)
J/AJ/127/3587 : VLBI ICRF. II (Fey+, 2004)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- IERS IERS name (HHMM+DDd, B1950)
10- 11 I2 h RAh Right ascension (J2000)
13- 14 I2 min RAm Right ascension (J2000)
16- 26 F11.8 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 44 F10.7 arcsec DEs Declination (J2000)
46- 56 F11.8 s/yr pmRA Apparent proper motion along RA
58- 67 F10.7 s/yr pmDE Apparent proper motion along DE
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 11-Apr-2014