The X/S Band (8.4/2.3 GHz) Celestial Reference Frame
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Description
Abstract: The X/S band(8.4/2.3GHz) Celestial Reference Frame is the largest of the three components of the ICRF3 released in 2018. In the nearly six years since, the X/S band data set has increased by ~25% to 5707 sources, based on ~7100 VLBI sessions and ~18.4millionobservations—a 40% increase since ICRF3. Observations using the VLBA have been key to densifying the frame. In particular, the density of sources near the ecliptic has been greatly improved making the frame more useful for spacecraft navigation. The latest solutions have median formal precisions of 107 μas in α cosδ and 189 μas in δ. Median number of sessions per source is 6, but with a much higher number for sources used regularly in geodesy.
The spherical harmonic distortions seen in the recent X/S-band CRF vs. ICRF3-X/S with the largest terms: Y-rotation -13 +- 2 μas, quadrupole 2,0 Mag 8.1 +- 1.8 µas and the quadrupole 2,0 electric term of 11.5 +- 2.2 µas. We note that the X/S-band frame is dominated by the all northern geometry of the VLBA. This results in some weakness in sources from the equator to -40 deg declination. Future improvements include the potential for increasing the VLBA data rates from 2 Gbps to 4 Gbps.
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XS-CRF_IVS-GM-24_v6.1.pdf
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References
- Charlot, Jacobs, et al, ICRF3, A&A, 644, A159, 2020. https://doi.org/10.1051/0004-6361/202038368
- Hunt et al, `Comparing Images of ICRF Sources at S, X, K, and Q-band,', IAU, FM7, 2022. https://doi.org/10.5281/zenodo.7068278
- de Witt et al, `Multi-Frequency Imaging Results of 452 Extragalactic ICRF-3 Radio Sources from Multi-Epoch, Near-Simultaneous Astrometric VLBA Observations. 15th EVN Symposium, Cork, Ireland, July 2022. https://www.ucc.ie/en/media/academic/physics/15thevn/2022/Aletha_deWitt.pdf
- Mignard and Klioner, Analysis of astrometric catalogues with vector spherical harmonics, A&A, 547, A59, 2012. https://doi.org/10.1051/0004-6361/201219927
- Gaia Collaboration, Gaia-CRF3, A&A, 667, A148, 2022. https://doi.org/10.1051/0004-6361/202243483
- Marscher, Relativistic Jets in AGN, Proc. AIP, 856, 2006. https://doi.org/10.1063/1.2356381
- Krichbaum, et al, High Angular Resolution Monitoring of Prominent AGN at 86 GHz, Proc. 2nd VLBI mm workshop, 1999. https://doi.org/10.48550/arXiv.astro-ph/9909176
- Wehrle, et al, Submillimeter, Near-Infrared and Optical Light Curves of Gamma-Ray Blazars, BAAS, 342, 375, 2010. https://ui.adsabs.harvard.edu/abs/2010AAS...21543405W/abstract