Zobrazeno 1 - 10
of 13
pro vyhledávání: '"Lambert, Sébastien"'
Autor:
Cigan, Phil, Makarov, Valeri, Secrest, Nathan, Gordon, David, Johnson, Megan, Lambert, Sebastien
Using very long baseline interferometry data for the sources that comprise the third International Celestial Reference Frame (ICRF3), we examine the quality of the formal source position uncertainties of ICRF3 by determining the excess astrometric va
Externí odkaz:
http://arxiv.org/abs/2408.01373
Astronomical time series often have non-uniform sampling in time, or irregular cadences, with long gaps separating clusters of observations. Some of these data sets are also explicitly non-Gaussian with respect to the expected model fit, or the simpl
Externí odkaz:
http://arxiv.org/abs/2405.12324
Autor:
Lambert, Sébastien, Bauzile, Billy, Mugnier, Amélie, Durand, Benoit, Vergne, Timothée, Paul, Mathilde C
The global spread of avian influenza A viruses in domestic birds is causing dramatic economic and social losses. Various mechanistic models have been developed in an attempt to better understand avian influenza transmission and to evaluate the effect
Externí odkaz:
http://arxiv.org/abs/2303.00394
We present an updated study on assessing the axes stability of the third generation of the International Celestial Reference Frame (ICRF3) in terms of linear drift and scatter based on the extragalactic source position time series from analyses of ar
Externí odkaz:
http://arxiv.org/abs/2206.15038
Autor:
Titov, Oleg, Frey, Sándor, Lambert, Sébastien, Shu, Fengchun, Xia, Bo, González, Javier, Tercero, Belén, Gulayev, Sergey, Weston, Stuart, Natusch, Tim
Astrometric positions of radio-emitting active galactic nuclei (AGNs) can be determined with sub-milliarcsec accuracy using very long baseline interferometry (VLBI). The usually small apparent proper motion of distant extragalactic targets allow us t
Externí odkaz:
http://arxiv.org/abs/2202.13119
Publikováno v:
A&A 659, A75 (2022)
The celestial reference frame is realized by absolute positions of extragalactic sources that are assumed to be fixed in the space. The fixing of the axes is one of the crucial points for the International Celestial Reference System (ICRS) concept. H
Externí odkaz:
http://arxiv.org/abs/2112.10079
Autor:
Liu, Niu, Lambert, Sebastien, Charlot, Patrick, Zhu, Zi, Liu, Jia-Cheng, Jiang, Nan, Wan, Xiao-Sheng, Ding, Cheng-Yu
Publikováno v:
A&A 652, A87 (2021)
We extend previous works by considering two additional radio frequencies (K band and X/Ka band) with the aim to study the frequency dependence of the source positions and its potential connection with the physical properties of the underlying AGN. We
Externí odkaz:
http://arxiv.org/abs/2105.12270
Autor:
Venturi, Tiziana, Paragi, Zsolt, Lindqvist, Michael, Bartkiewicz, Anna, Beswick, Rob, Bogdanović, Tamara, Brisken, Walter, Charlot, Patrick, Colomer, Francisco, Conway, John, Frey, Sándor, Guirado, José Carlos, Gurvits, Leonid, van Langevelde, Huib, Lobanov, Andrei, McKean, John, Morganti, Raffaella, Muxlow, Tom, Pérez-Torres, Miguel, Rygl, Kazi, Schulz, Robert, Szomoru, Arpad, de Vicente, Pablo, An, Tao, Anglada, Guillem, Argo, Megan, Azulay, Rebecca, van Bemmel, Ilse, Bocanegra, Tatiana, Boccardi, Biagina, Castangia, Paola, Chibueze, James, Cimò, Giuseppe, Climent, Juan-Bautista, Deane, Roger, Deller, Adam, Dodson, Richard, Duev, Dmitry, Etoka, Sandra, Fenech, Danielle, Gabányi, Krisztina, Gabuzda, Denise, Garrett, Michael, Gawroński, Marcin, Ghirlanda, Giancarlo, Giroletti, Marcello, Goddi, Ciriaco, Gómez, Jose Luis, Gray, Malcolm, Greaves, Jane, Hessels, Jason, van der Horst, Alexander, Hunter, Todd, Laing, Robert, Lal, Dharam Vir, Lambert, Sébastien, Loinard, Laurent, Marcote, Benito, Merloni, Andrea, Miller-Jones, James, Calvés, Guifré Molera, Moscadelli, Luca, Olofsson, Hans, Petrov, Leonid, Pizzo, Roberto, Possenti, Andrea, Quiroga-Nuñez, Luis Henry, Reynolds, Cormac, Richards, Anita, Rioja, Maria, Sanna, Alberto, Savolainen, Tuomas, Sbarrato, Tullia, Spingola, Cristiana, Surcis, Gabriele, Trigilio, Corrado, Varenius, Eskil, Vlemmings, Wouter, van Velzen, Sjoert, van der Walt, Johan
This white paper describes the science case for Very Long Baseline Interferometry (VLBI) and provides suggestions towards upgrade paths for the European VLBI Network (EVN). The EVN is a distributed long-baseline radio interferometric array, that oper
Externí odkaz:
http://arxiv.org/abs/2007.02347
Publikováno v:
A&A 634, A28 (2020)
We aim to investigate the overall properties of the ICRF3 with the help of the Gaia Data release 2 (Gaia DR2). This could serve as an external check of the quality of the ICRF3. The radio source positions of the ICRF3 catalog were compared with the G
Externí odkaz:
http://arxiv.org/abs/1912.07396
Autor:
Titov, Oleg, Lambert, Sebastien, Soja, Benedikt, Shu, Fengchun, Melnikov, Alexei, McCallum, Jamie, McCallum, Lucia, Schartner, Matthias, de Witt, Aletha, Ivanov, Dmitrii, Mikhailov, Andrei, Yi, Sang Oh, Chen, Wen, Xia, Bo, Ishigaki, Masafumi, Gulyaev, Sergei, Natusch, Tim, Weston, Stuart
Geodetic Very Long Baseline Interferometry (VLBI) data are capable of measuring the light deflection caused by the gravitational field of the Sun and large planets with high accuracy. The parameter $\gamma$ of the parametrized Post-Newtonian (PPN) fo
Externí odkaz:
http://arxiv.org/abs/1908.00973