THE SECOND REALIZATION OF THE INTERNATIONAL CELESTIAL REFERENCE FRAME BY VERY LONG BASELINE INTERFEROMETRY

By Chopo Ma, E. F. Arias, G. Bianco, D. Boboltz, S. Bolotin, P. Charlot, G. Engelhardt, A. Fey, R. Gaume, A. Gontier and 23 more. 2015

413 citations recorded by the source corpus.

We present the second realization of the International Celestial Reference Frame (ICRF2) at radio wavelengths using nearly 30 years of Very Long Baseline Interferometry observations. ICRF2 contains precise positions of 3414 compact radio astronomical objects and has a positional noise floor of ∼40 μas and a directional stability of the frame axes of ∼10 μas. A set of 295 new “defining” sources was selected on the basis of positional stability and the lack of extensive intrinsic source structure. The positional stability of these 295 defining sources and their more uniform sky distribution eliminates the two greatest weaknesses of the first realization of the International Celestial Reference Frame (ICRF1). Alignment of ICRF2 with the International Celestial Reference System was made using 138 positionally stable sources common to both ICRF2 and ICRF1. The resulting ICRF2 was adopted by the International Astronomical Union as the new fundamental celestial reference frame, replacing ICRF1 as of 2010 January 1.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/a2034ad14cab04663aa207f6d1a51a8709086666

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In Astronomy and Astrophysics

1. Y. Kovalev
2. A. Pushkarev
3. A. Lobanov
4. Robert Heinkelmann
5. D. R. Lorimer
6. S. Burke-Spolaor
7. O. Paris
8. C. I. O. Technology.

Citations in the corpus

• The Hipparcos–Gaia Catalog of Accelerations (2018, methodology): “Both catalogs are calibrated to the International Celestial Reference System (ICRS, Ma et al. 1998; Fey et al. 2015), but neither one perfectly realizes this reference frame.”
• The IERS EOP 14C04 solution for Earth orientation parameters consistent with ITRF 2014 (2019, methodology): “2011) and to the second realization of the International Celestial Reference Frame (ICRF2) (Fey et al. 2015).”
• IDENTIFICATION OF 1.4 MILLION ACTIVE GALACTIC NUCLEI IN THE MID-INFRARED USING WISE DATA (2015, background): “The second realization, ICRF2, consists of 3,414 compact radio objects (i.e., QSOs), of which 295 are “defining sources” (Fey et al. 2015).”
• VLBI: A fascinating technique for geodesy and astrometry (2012, background): “The ICRF2 replaced the previously used first realization (ICRF) effective 1 January 2010.”
• The third realization of the International Celestial Reference Frame by very long baseline interferometry (2020, methodology): “In the realization of ICRF2, those sources were treated as arc parameters (i.e., a new position was estimated for each session) and denoted as special handling sources (Fey et al. 2015).”
• A VLBA survey of the core shift effect in AGN jets - I. Evidence of dominating synchrotron opacity (2011, methodology): “In the particular case of k = 1, if the radio source is strongly core-dominated, its position measured using the group delay technique at any frequency (such as those currently used to define the the International Celestial Reference Frame, ICRF, Ma et al. 1998; Fey et al. 2004, and ICRF2, Fey et al”
• The NANOGrav 11-year Data Set: High-precision Timing of 45 Millisecond Pulsars (2017, methodology): “All positions and proper motions are relative to the reference frame of the JPL DE436 solar system ephemeris used to reduce these data; this in turn is aligned with the Second Realization of the International Celestial Reference Frame (Fey et al. 2015, ICRF2).”