منابع مشابه
Maser Astrometry with VLBI and the SKA
We discuss the unique opportunities for maser astrometry with the inclusion of the Square Kilometre Array (SKA) in Very Long Baseline Interferometry (VLBI) networks. The first phase of the SKA will enable observations of hydroxyl and methanol masers, positioning the latter to an accuracy of 5 microarcseconds, and the second phase may allow water maser observations. These observations will provi...
متن کاملSpace - VLBI phase - reference mapping and astrometry
We present 5 GHz space-VLBI observations of the quasar pair B 1342+662 / B 1342+663 that demonstrate the feasibility of phase-reference techniques using an antenna in space. The space-based data were taken by the satellite HALCA, of the space-VLBI mission VSOP. From residual (referenced) phases we derive an upper bound of 10 meters to the uncertainty of the spacecraft orbit reconstruction. An a...
متن کاملImproved VLBI astrometry of OH maser stars
Aims. Accurate distances to evolved stars with high mass loss rates are needed for studies of many of their fundamental properties. However, as these stars are heavily obscured and variable, optical and infrared astrometry is unable to provide enough accuracy. Methods. Astrometry using masers in the circumstellar envelopes can be used to overcome this problem. We have observed the OH masers of ...
متن کاملPrecision VLBI astrometry: Instrumentation, algorithms and pulsar parallax determination
This thesis describes the development of DiFX, the first general–purpose software correlator for radio interferometry, and its use with the Australian Long Baseline Array to complete the largest Very Long Baseline Interferometry (VLBI) pulsar astrometry program undertaken to date in the Southern Hemisphere. This two year astrometry program has resulted in the measurement of seven new pulsar par...
متن کاملLetter to the Editor VLBI difference astrometry at 43 GHz
From 43 GHz VLBA observations of the pair of radio sources QSO 1928+738 and BL 2007+777 we have demonstrated the feasibility of precision phase-delay differential astrometric techniques at millimeter wavelengths. For a pair of sources with 5◦ separation and high antenna elevations, we have shown that present astrometric models and millimeter arrays are advanced enough to model the differential ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1994
ISSN: 0074-1809
DOI: 10.1017/s0074180900108149