Results 151 to 160 of about 22,374 (269)

The first scientific experiment using Global e-VLBI observations: a multiwavelength campaign on the gamma-ray Narrow-Line Seyfert 1 PMN J0948+0022 [PDF]

open access: yes, 2010
The detection of gamma-ray emission by Fermi-LAT from the radio loud Narrow Line Seyfert 1 PMN J0948+0022 (Abdo et al. 2009, ApJ 699, 976) triggered a multi-wavelength campaign between March and July 2009. Given its high compactness (Doi et al.
Paragi, Zsolt   +16 more
core  

Prospects of Detecting a Jet in Sagittarius A* with Very-long-baseline Interferometry

open access: yesThe Astrophysical Journal
Event Horizon Telescope (EHT) images of the horizon-scale emission around the Galactic center supermassive black hole Sagittarius A* (Sgr A*) favor accretion flow models with a jet component. However, this jet has not been conclusively detected.
Erandi Chavez   +5 more
doaj   +1 more source

A Simulator to Generate VLBI Baseband Data in Matlab

open access: yes, 2019
VLBI radio telescopes represent a sophisticated interconnection of electronic devices. The final product of each observation by a radio telescope is the baseband data. In this presentation, we show a software tool as part of the Vienna VLBI and Satellite
Schartner, Matthias   +3 more
core  

Tsukuba VLBI Correlator [PDF]

open access: yes, 2013
The K5/VSSP software correlator (Figure 1), located in Tsukuba, Japan, is operated by the Geospatial Information Authority of Japan (GSI). It is fully dedicated to processing the geodetic VLBI sessions of the International VLBI Service for Geodesy and ...
Kurihara, Shinobu, Nozawa, Kentaro
core  

Geodetic Italian VLBI: first tests [PDF]

open access: yes, 2015
First experiments of the Italian VLBI network (VITA) correlated in Bologna have involved the Medicina, Noto and Matera antennas. Although the scientific validity of these tests are yet to be proven, these experiments have served as a benchmark to ...
NEGUSINI, MONIA, STAGNI, Matteo
core  

Automated Modeling with AAP-Imfit: Astrometry and Photometry via CASA

open access: yesThe Astrophysical Journal
Very long baseline interferometry (VLBI) provides the highest-resolution radio intensity maps, crucial for detailed studies of compact sources like active galactic nuclei (AGNs) and their relativistic jets.
Alfredo Amador-Portes   +5 more
doaj   +1 more source

A pilot very long baseline interferometry study of the SQUAB quasar sample featuring multiple Gaia detections

open access: yesAstronomy & Astrophysics
Context. Our previous work identified a class of SDSS quasars with multiple Gaia detections, classifying them as candidates for various astrophysical systems, such as quasar–star pairs, dual quasars, and gravitationally lensed quasars.
Zhang Y.   +7 more
doaj   +1 more source

VLBI Astrometry

open access: yes, 2003
Latex, 6 pages, 8 figures; Invited Review Talk at the ``ADeLA2002 - Astrometry in Latin America'' Conference, Araraquara - Sao Paulo, 2 - 5 September 2002, to be published in ADeLA Publications Series, Vol.
openaire   +2 more sources

VLBI observations of H2O masers towards high-mass Young Stellar Objects [PDF]

open access: yes, 2004
We have conducted multi-epoch VLBI observations of the 22.2 GHz water masers towards three massive star forming regions (Sh 2-255 IR, WB89-234, AFGL 5142). For the maser fetures persistent in time, accurate values of the proper motions are derived.
MOSCADELLI, Luca, Goddi, C.
core  

Estimation of Earth Rotation Parameters Based on BDS-3 and Discontinuous VLBI Observations

open access: yesRemote Sensing
Earth rotation parameters (ERPs) are fundamental to geodetic and astronomical studies. With its high measurement accuracy and stability, the Very Long Baseline Interferometry (VLBI) plays an irreplaceable role in estimating the ERPs and maintaining the ...
Chenxiang Wang   +3 more
doaj   +1 more source

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