Results 1 to 10 of about 11,774 (188)

Radio astrometry with chromatic AGN core positions [PDF]

Astronomy and Astrophysics, 2009
Aims: The effect of frequency-dependent AGN core positions (``core-shifts'') on radio Very Long Baseline Interferometry (VLBI) global astrometry measurements is investigated.
R W Porcas
exaly   +5 more sources

The Radio Fundamental Catalog. I. Astrometry

The Astrophysical Journal Supplement Series
We present an all-sky catalog of absolute positions and estimates of correlated flux density of 21,942 compact radio sources determined from processing interferometric visibility data of virtually all very long baseline interferometry (VLBI) observing ...
L. Y. Petrov, Y. Y. Kovalev
doaj   +4 more sources

Micro-Arcsecond Radio Astrometry [PDF]

Annual Review of Astronomy and Astrophysics, 2013
Astrometry provides the foundation for astrophysics. Accurate positions are required for the association of sources detected at different times or wavelengths, and distances are essential to estimate the size, luminosity, mass, and ages of most objects ...
Honma, M., Reid, M. J.
core   +2 more sources

Radio Astrometry at Different Frequencies

The Astronomical Journal
The very long baseline interferometry technique allows us to determine the positions of thousands of radio sources using the absolute astrometry approach. I have investigated the impacts of a selection of observing frequencies in a range from 2 to 43 GHz
Leonid Petrov
doaj   +2 more sources

Precise radio astrometry and new developments for the next generation of instruments [PDF]

Astronomy and Astrophysics Review, 2020
We present a technique-led review of the progression of precise radio astrometry, from the first demonstrations, half a century ago, until to date and into the future. We cover the developments that have been fundamental to allow high accuracy and precision astrometry to be regularly achieved. We review the opportunities provided by the next-generation
Maria J Rioja, Richard Dodson
exaly   +3 more sources

An Updated View of the Milky Way from Maser Astrometry

Universe, 2022
Astrometric observations of maser sources in the Milky Way, using the Very Long Baseline Interferometry (VLBI) technique, have been exploited to determine the spiral structure of our Galaxy. Several major spiral arms have now been pinpointed in the first
Katharina Immer, Kazi L. J. Rygl
doaj   +3 more sources

The Present Status of Astrometry at Optical and Radio Wavelengths [PDF]

Symposium - International Astronomical Union, 1994
A Review is presented of the present status of astrometry towards defining a radio/optical reference frame.
K J Johnston
exaly   +2 more sources

Radio Astrometry Using Connected-Element Interferometers [PDF]

Symposium - International Astronomical Union, 1974
The basic techniques of conventional radio interferometry are explained and a review given of the achievements and limitations of the methods as applied to radio astrometry.
B Elsmore
exaly   +2 more sources

Astrometry and geodesy with radio interferometry: experiments, models, results [PDF]

Reviews of Modern Physics, 1997
Summarizes current status of radio interferometry at radio frequencies between Earth-based receivers, for astrometric and geodetic applications. Emphasizes theoretical models of VLBI observables that are required to extract results at the present ...
Aoki, S., Argus, D. F., Argus, D. F., Argus, D. F., Baader, H.-R., Bare, C., Bartel, N., Bassiri, S., Batty, M. J., Bolton, J. G., Bowring, B. R., Brosche, P., Brosche, P., Brosche, P., Brosche, P., Broten, N. W., Burke, B. F., Carr, T. D., Carter, W. E., Cartwright, D. E., Chao, B. F., Chao, B. F., Charlot, P., Charlot, P., Charlot, P., Chen, G., Christopher S. Jacobs, Clark, T. A., Clark, T. A., Cohen, M. H., Cohen, M. H., Davidson, J. M., Davis, J. L., DeMets, C., DeMets, C., Dreyer, J. L. E., Edge, D. O., Einstein, A., Einstein, A., Elgered, G., Fairhead, L., Fallon, F. W., Fang, M., Fey, A. L., Fich, M., Folkner, W. M., Freedman, A. P., Fu, L. L., Fukushima, T., Fukushima, T., Gardner, C. S., Gardner, C. S., Gaspar, P., Gilbert, F., Gipson, J. M., Gross, R. S., Gwinn, C. R., Gwinn, C. R., Haas, R., Hartmann, T., Hartmann, T., Hartmann, T., Hellings, R. W., Henstock, D. R., Herring, T. A., Herring, T. A., Herring, T. A., Herring, T. A., Hinteregger, H. F., Hjellming, R. M., Ho, C. M., Hosokawa, M., Hubble, E. P., Jacobs, C. S., Jansky, K. G., Jansky, K. G., John L. Fanselow, Johnston, K. J., Kellermann, K. I., Kerr, F. J., Kinoshita, H., Kinoshita, H., Kogut, A., Kovalevsky, J., Le Provost, C., Lebach, D. E., Lestrade, J.-F., Lestrade, J.-F., Lieske, J. H., Linfield, R. P., Ma, C., Ma, C., MacDoran, P. F., MacMillan, D. S., MacMillan, D. S., MacMillan, D. S., Marcaide, J. M., Marini, J. W., Mathews, P. M., Mathews, P. M., Mathews, P. M., May, J., Minster, J. B., Mitrovica, J. X., Moran, J. M., Morgan, P. J., Moyer, T. D., Napier, P. J., Naudet, C. J., Niell, A. E., Ojars J. Sovers, Ong, K. M., Pagiatakis, S. D., Patnaik, A., Peltier, W. R., Piner, B. G., Polatidis, A. G., Pyne, T., Rabbel, W., Ray, J. R., Ray, J. R., Ray, R. D., Reber, G., Reber, G., Reid, M. J., Rius, A., Robertson, D. S., Robertson, D. S., Robertson, D. S., Robertson, D. S., Robertson, D. S., Rogers, A. E. E., Rogers, A. E. E., Rosen, R. D., Scherneck, H. G., Schmidt, M., Seidelmann, P. K., Seiler, U., Shahid-Saless, B., Shapiro, I. I., Shapiro, I. I., Smith, E. K., Sonett, C. P., Souchay, J., Sovers, O. J., Sovers, O. J., Sovers, O. J., Standish, E. M., Taylor, G. B., Teitelbaum, L. P., Thakkar, D. D., Thayer, G. D., Treuhaft, R. N., Treuhaft, R. N., Tushingham, A. M., van Dam, T. M., van Dam, T. M., van Vleck, J. H., Vigue, Y., Wade, C. M., Wade, C. M., Wahr, J. M., Wahr, J. M., Walter, H. G., Walter, H. G., Ward, S. N., Watkins, M. M., Webb, F. H., Williams, J. G., Williams, J. G., Williams, J. G., Wilson, B. D., Yahil, A., Yoder, C. F., Zebker, H. A., Zhu, S. Y., Zhu, S. Y.   +176 more
core   +3 more sources

Accurate Astrometry of 22 Southern Hemisphere Radio Sources [PDF]

Astronomical Journal, 2004
Milliarcsecond-accurate radio positions for 22 southern hemisphere extragalactic sources are reported. These positions are derived from Mark III very long baseline interferometry observations made between 2003 February and 2003 August. The results presented here supplement an ongoing project to increase the sky density of southern hemisphere sources in
Alan L Fey, David L Jauncey, Kenneth J Johnston   +2 more
exaly   +2 more sources