Results 91 to 100 of about 11,697 (215)

Radio-loudness Statistics of Quasars from Quaia-VLASS

The Astrophysical Journal Supplement Series
Quasars are objects of high interest in extragalactic astrophysics, cosmology, and astrometry. One of their useful qualities is their potential radio-loudness.
Nestor Arsenov, Sándor Frey, András Kovács, Lyuba Slavcheva-Mihova   +3 more
doaj   +1 more source

VERA monitoring of a blazar OJ 287

EPJ Web of Conferences, 2013
We present the frequent VLBI monitoring results of blazar OJ 287 at 22 GHz band using the VLBI Exploration of Radio Astrometry (VERA) from 2010 November to 2012 September. Time interval of the monitoring is typically once or twice per month.
Sawada-Satoh S., Akiyama K., Kino M., Nagai H., Niinuma K.   +4 more
doaj   +1 more source

Radio Astrometry [PDF]

The utilization of conventional and VLBI interferometer techniques for accurate determination of UTI, polar motion, and radio source position catalog data is ...
Johnston, K. J.
core   +1 more source

VLBI Astrometry of the Stellar Image of U Herculis, Amplified by the 1667 OH Maser [PDF]

, 2000
The OH 1667 MHz maser in the circumstellar shell around the Mira variable U Herculis has been observed with the NRAO Very Long Baseline Array (VLBA) at 6 epochs, spread over 4 years.
Baudry, A., Beasley, A. J., Diamond, P. J., van Langevelde, H. J., Vlemmings, W.   +4 more
core   +2 more sources

VLA+PT Astrometry of 46 Radio Stars

, 2006
We have used the Very Large Array (VLA), linked with the Pie Town Very Long Baseline Array antenna, to determine astrometric positions of 46 radio stars in the International Celestial Reference Frame (ICRF). Positions were obtained in the ICRF directly through phase referencing of the stars to nearby ICRF quasars whose positions are accurate at the 0 ...
Boboltz, D. A., Fey, A. L., Puatua, W. K., Zacharias, N., Claussen, M. J., Johnston, K. J., Gaume, R. A.   +6 more
openaire   +2 more sources

Radio Follow-up Observations of SN 2023ixf by Japanese and Korean Very Long Baseline Interferometers

The Astrophysical Journal
We report on radio follow-up observations of the nearby Type II supernova SN 2023ixf, spanning from 1.7 to 269.9 days after the explosion, conducted using three very long baseline interferometers (VLBIs), which are the Japanese VLBI Network, the VLBI ...
Yuhei Iwata, Masanori Akimoto, Tomoki Matsuoka, Keiichi Maeda, Yoshinori Yonekura, Nozomu Tominaga, Takashi J. Moriya, Kenta Fujisawa, Kotaro Niinuma, Sung-Chul Yoon, Jae-Joon Lee, Taehyun Jung, Do-Young Byun   +12 more
doaj   +1 more source

Opacity in compact extragalactic radio sources and its effect on astrophysical and astrometric studies

, 2008
The apparent position of the "core" in a parsec-scale radio jet (a compact, bright emitting region at the narrow end of the jet) depends on the observing frequency, owing to synchrotron self-absorption and external absorption.
A. B. Pushkarev, A. P. Lobanov, Afanasiev, Beasley, Bietenholz, Blandford, Blandford, Bloom, Böttcher, Charlot, Cohen, Croke, Fey, Fey, Fey, Fomalont, Frey, Hirotani, Hirotani, Homan, Hutter, J. A. Zensus, Jennison, Johnston, Junor, Kadler, Kellermann, Kovalev, Kovalev, Kovalevsky, Königl, Lara, Lestrade, Lindegren, Lobanov, Lobanov, Lobanov, Lobanov, Lobanov, Ma, Marcaide, Marscher, Peterson, Petrov, Petrov, Readhead, Shao, Souchay, Sowards-Emmerd, Vermeulen, Véron-Cetty, Walker, Y. Y. Kovalev   +52 more
core   +1 more source

Space Radio Astronomy in the next 1000001 (binary) years

, 2012
Radio astronomy and active exploration of space are peers: both began by efforts of enthusiasts in the 1930s and got a major technological boost in the 1940s-50s.
Gurvits, L. I.
core   +1 more source

A Geodetic and Astrometric VLBI Experiment at 22/43/88/132 GHz

The Astronomical Journal
Extending geodetic and astrometric Very Long Baseline Interferometry (VLBI) observations from traditional centimeter wavebands to millimeter wavebands offers numerous scientific potentials and benefits. However, it was considered quite challenging due to
Shuangjing Xu, Taehyun Jung, Bo Zhang, Ming Hui Xu, Do-Young Byun, Xuan He, Nobuyuki Sakai, Oleg Titov, Fengchun Shu, Hyo-Ryoung Kim, Jungho Cho, Sung-Moon Yoo, Byung-Kyu Choi, Woo Kyoung Lee, Yan Sun, Xiaofeng Mai, Guangli Wang   +16 more
doaj   +1 more source

Lunar radio astrometry [PDF]

The accuracy of Earth-based radio astronomy is limited in a fundamental way by the variable delay of the troposphere and by the centimeter-scale motions of a dynamic Earth.
Linfield, Roger
core   +1 more source