Zobrazeno 1 - 10
of 46
pro vyhledávání: '"Alan L. Fey"'
Autor:
Tobias Nilsson, R. Gaume, Axel Nothnagel, E. Skurikhina, Zinovy Malkin, Patrick Charlot, S. Bolotin, David Gordon, David Mayer, A. de Witt, Johannes Böhm, Sébastien Lambert, O. Titov, Alan L. Fey, Christopher S. Jacobs, E. F. Arias, Robert Heinkelmann, Dan MacMillan, Chopo Ma, Geraldine Bourda
Publikováno v:
Astronomy and Astrophysics-A&A
Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 644, pp.A159. ⟨10.1051/0004-6361/202038368⟩
Astronomy and Astrophysics
Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 644, pp.A159. ⟨10.1051/0004-6361/202038368⟩
Astronomy and Astrophysics
A new realization of the International Celestial Reference Frame (ICRF) is presented based on the work achieved by a working group of the International Astronomical Union (IAU) mandated for this purpose. This new realization, referred to as ICRF3, is
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::821c32215725e1896767e2ac71f1c124
http://hdl.handle.net/20.500.12278/95208
http://hdl.handle.net/20.500.12278/95208
The VLBI USNO 2016A (U16A) solution is part of a work-in-progress effort by USNO towards the preparation of the ICRF3. Most of the astrometric improvement with respect to the ICRF2 is due to the re-observation of the VCS sources. Our objective in thi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fdca2cf844b915b805eca602089f0c13
We investigate a sample of 3412 {\it International Celestial Reference Frame} (ICRF3) extragalactic radio-loud sources with accurate positions determined by VLBI in the S/X band, mostly active galactic nuclei (AGN) and quasars, which are cross-matche
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8288619da51e11c6a9042200c565a2c7
Autor:
Alan L. Fey, Alison B. Peck, David Gordon, Chopo Ma, David A. Boboltz, Anthony Beasley, Ralph A. Gaume, Christopher S. Jacobs, Patrick Charlot, Oleg Titov
Publikováno v:
The Astronomical Journal
The Astronomical Journal, American Astronomical Society, 2016, 151 (6), pp.id. 154. ⟨10.3847/0004-6256/151/6/154⟩
The Astronomical Journal, American Astronomical Society, 2016, 151 (6), pp.id. 154. ⟨10.3847/0004-6256/151/6/154⟩
International audience; Six very successful Very Long Baseline Array (VLBA) calibrator survey campaigns were run between 1994 and 2007 to build up a large list of compact radio sources with positions precise enough for use as very long baseline inter
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6286867bb64e48fcfebc95509ec02ba8
https://europepmc.org/articles/PMC6010998/
https://europepmc.org/articles/PMC6010998/
Autor:
Patrick Charlot, L. D. Zhang, David A. Boboltz, B. J. Geldzahler, G. E. Lanyi, Alan L. Fey, Edward B. Fomalont, O. J. Sovers, Christopher S. Jacobs, C. J. Naudet, Chopo Ma, David Gordon, Jonathan D. Romney
Publikováno v:
The Astrophysical Journal
The Astrophysical Journal, American Astronomical Society, 2010, 139 (5), pp.1713-1770. ⟨10.1088/0004-6256/139/5/1713⟩
The Astrophysical Journal, American Astronomical Society, 2010, 139 (5), pp.1713-1770. ⟨10.1088/0004-6256/139/5/1713⟩
We have measured the sub-milli-arcsecond structure of 274 extragalactic sources at 24 and 43 GHz in order to assess their astrometric suitability for use in a high frequency celestial reference frame (CRF). Ten sessions of observations with the Very
Autor:
Brian Chaboyer, Jo Eliza Pitesky, Louis E. Strigari, Joseph Catanzarite, Angelle Tanner, Dayton L. Jones, Michael Shao, Geoffrey W. Marcy, Guy Worthey, David R. Ciardi, Edward J. Shaya, Ronald J. Allen, Stephen J. Edberg, David A. Boboltz, Debra A. Fischer, Nicholas M. Law, Xiaopei Pan, Andreas Quirrenbach, Stephen C. Unwin, Charles A. Beichman, Steven R. Majewski, Alan L. Fey, Ann E. Wehrle, Carl J. Grillmair, Christopher R. Gelino, Richard J. Patterson, Shrinivas R. Kulkarni, Kenneth J. Johnston, Stuart Shaklan, Todd J. Henry, John A. Tomsick, Kathryn V. Johnston, Andrew Gould, Rob P. Olling, Valeri V. Makarov, David L. Meier
Publikováno v:
Publications of the Astronomical Society of the Pacific. 120:38-88
Precision astrometry at microarcsecond accuracy has application to a wide range of astrophysical problems. This paper is a study of the science questions that can be addressed using an instrument that delivers parallaxes at about 4 microarcsec on tar
Autor:
Anastasios Tzioumis, Simon Ellingsen, P. M. McCulloch, Alan L. Fey, Roopesh Ojha, Jonathan Quick, James E. J. Lovell, David L. Jauncey, John Reynolds, George D. Nicolson, Kenneth J. Johnston
Publikováno v:
The Astronomical Journal. 132:1944-1949
Milliarcsecond-accurate radio positions in the International Celestial Reference Frame for 34 southern hemisphere extragalactic sources are reported. The positions are derived from Mark III/IV very long baseline interferometry observations made betwe
Autor:
Roopesh Ojha, David L. Jauncey, T. Joseph W. Lazio, Alan L. Fey, Lucyna Kedziora-Chudczer, James E. J. Lovell
Publikováno v:
The Astrophysical Journal Supplement Series. 166:37-68
Multiwavelength Very Long Baseline Array observations of a sample of 49 extragalactic radio sources selected from the Micro-Arcsecond Scintillation-Induced Variability survey are presented. These observations are intended to provide a sizeable, unifo
Autor:
Simon Garrington, Ralph A. Gaume, Kenneth J. Johnston, P. Thomasson, David A. Boboltz, Alan L. Fey
Publikováno v:
The Astronomical Journal. 131:1084-1089
We report accurate positions in the International Celestial Reference Frame (ICRF) for 11 radio stars. Observations were made using the Multi-Element Radio Linked Interferometer Network at a radio frequency of 5 GHz. The positions are estimated to be
Autor:
P. M. McCulloch, Roopesh Ojha, Alan L. Fey, John Reynolds, Simon Ellingsen, Kenneth J. Johnston, David L. Jauncey
Publikováno v:
The Astronomical Journal. 128:2593-2598
Milliarcsecond-accurate radio positions for 25 southern hemisphere extragalactic sources are reported. These positions are derived from Mark III Very Long Baseline Interferometry observations made between 2003 September and 2004 May on the intra-Aust