Optical astrometric positions of 59 northern ICRF radio sources
| Autor: | Petre Popescu, Octavian Badescu, Dan Alin Nedelcu, R. Vieira Martins, Marcelo Assafin, D. N. da Silva Neto, A. H. Andrei, Julio Camargo |
|---|---|
| Přispěvatelé: | Observatório do Valongo, Universidade Federal do Rio de Janeiro, Astronomical Institute of the Romanian Academy, Bucharest, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Observatório Nacional/MCTI, Systèmes de Référence Temps Espace (SYRTE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Systèmes de référence célestes, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2007 |
| Předmět: |
Physics
media_common.quotation_subject Astronomy Astronomy and Astrophysics Context (language use) Quasar Astrophysics Astrometry law.invention Telescope Space and Planetary Science Observatory Sky law Magnitude (astronomy) International Celestial Reference Frame [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] media_common |
| Zdroj: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, 2007, 476, pp.989-993. ⟨10.1051/0004-6361:20078441⟩ |
| ISSN: | 1432-0746 0004-6361 |
| Popis: | International audience; Context: To investigate the link between the International Celestial Reference Frame (ICRF) and its optical Hipparcos-based representation on the northern hemisphere. Aims: To present results of a pilot investigation on the astrometry of 59 northern ICRF sources. Methods: We used the 0.6 m Zeiss telescope at Belogradchik Observatory, Bulgaria. The optical CCD source positions were referred to the UCAC2 catalog. Improved astrometric methods were applied including telescope shifting between exposures, (x, y) Gaussian measurements within 1 full width at half maximum, and the observation of a large number of frames per source. The huge amount of data generated was treated with a new astrometric package, PRAIA (Platform for Reduction of Astronomical Images Astrometrically). Results: Average and standard deviation for the optical minus radio position offsets were +6 mas (51 mas) and +7 mas (57 mas) for RA and Dec, respectively. The errors of all (x, y) measurements from Gaussian fits displayed a typical distribution with respect to magnitude, dependent on the sky transparency. For the ICRF objects, the (x, y) errors per source ranged from 50 mas to 100 mas. The RA and Dec reduction mean errors were 46 mas. Conclusions: No large scale systematic errors with respect to RA or Dec were found within the attained position precision. Comparison with three independent telescope/catalog datasets shows that the precision obtained here represents an important improvement on previous works. In comparison with the southern hemisphere, more astrometry on ICRF sources are needed in the north, and it is shown here that the continuation of this program can fill this need. |
| Databáze: | OpenAIRE |
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