2011AJ....141..114R -
Astron. J., 141, 114 (2011/April-0)
High-precision astrometric millimeter very long baseline interferometry using a new method for atmospheric calibration.
RIOJA M. and DODSON R.
Abstract (from CDS):
We describe a new method which achieves high-precision very long baseline interferometry (VLBI) astrometry in observations at millimeter (mm) wavelengths. It combines fast frequency-switching observations, to correct for the dominant non-dispersive tropospheric fluctuations, with slow source-switching observations, for the remaining ionospheric dispersive terms. We call this method source-frequency phase referencing. Provided that the switching cycles match the properties of the propagation media, one can recover the source astrometry. We present an analytic description of the two-step calibration strategy, along with an error analysis to characterize its performance. Also, we provide observational demonstrations of a successful application with observations using the Very Long Baseline Array at 86 GHz of the pairs of sources 3C274 and 3C273 and 1308+326 and 1308+328 under various conditions. We conclude that this method is widely applicable to mm-VLBI observations of many target sources, and unique in providing bona fide astrometrically registered images and high-precision relative astrometric measurements in mm-VLBI using existing and newly built instruments, including space VLBI.
Abstract Copyright:
∼
Journal keyword(s):
astrometry - methods: data analysis - techniques: high angular resolution - techniques: interferometric
Simbad objects:
5
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2011AJ....141..114R and select 'bookmark this link' or equivalent in the popup menu