Inverse Multview I: Multi-Calibrator inverse phase referencing for Microarcsecond VLBI Astrometry

Autor:	Hyland, Lucas J., Reid, Mark J., Ellingsen, Simon P., Rioja, Maria J., Dodson, Richard, Orosz, Gabor, Masson, Colin R., McCallum, Jamie M.
Rok vydání:	2022
Předmět:	Astrophysics - Instrumentation and Methods for Astrophysics Astrophysics - Astrophysics of Galaxies
Zdroj:	2022 ApJ 932 52
Druh dokumentu:	Working Paper
DOI:	10.3847/1538-4357/ac6d5b
Popis:	Very Long Baseline Interferometry (VLBI) astrometry is a well established technique for achieving $\pm10~\mu$as parallax accuracies at frequencies well above 10~GHz. At lower frequencies, uncompensated interferometer delays associated with the ionosphere play the dominant role in limiting the astrometric accuracy. Multiview is a novel VLBI calibration method, which uses observations of multiple quasars to accurately model and remove time-variable, directional-dependent changes to the interferometer delay. Here we extend the Multiview technique by phase referencing data to the target source ("inverse Multiview") and test its performance. Multiple observations with a four-antenna VLBI array operating at 8.3~GHz show single-epoch astrometric accuracies near $20~\mu$as for target-reference quasar separations up to about 7 degrees. This represents an improvement in astrometric accuracy by up to an order of magnitude compared to standard phase referencing. Comment: 11 pages, 5 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2205.00092 Zobrazit plný text záznamu View this record from Arxiv