Results 81 to 90 of about 27,177 (193)

Masses of Nearby Supermassive Black Holes with Very-Long Baseline Interferometry

, 2011
Dynamical mass measurements to date have allowed determinations of the mass M and the distance D of a number of nearby supermassive black holes. In the case of Sgr A*, these measurements are limited by a strong correlation between the mass and distance ...
Agol, Bendo, Bower, Broderick, Broderick, Broderick, Daniel P. Marrone, Dexter, Dimitrios Psaltis, Doeleman, Doeleman, Dolence, Eisenhauer, Falcke, Falcke, Feryal Özel, Fish, Fish, Ghez, Gillessen, Gültekin, Ho, Johannsen, Kardashev, Laor, Lee, Leeuw, Mościbrodzka, Pellegrini, Shcherbakov, Sheperd S. Doeleman, Stefan Gillessen, Takahashi, Tim Johannsen, Viergutz, Vincent L. Fish, Yuan, Özel   +37 more
core   +1 more source

Role of Barystatic Sea Level Change in Global Mass Conservation and Its Excitation to Length‐Of‐Day Variations

Earth and Space Science, Volume 12, Issue 1, January 2025.
Abstract Barystatic sea level stores excess water mass from the atmosphere and land to maintain global mass conservations within the Earth system. Besides the secular contribution to global sea‐level rise, changes in barystatic sea level also play an important role in mass‐induced length‐of‐day (LOD) variations over a few years or shorter periods ...
Qiqi Shi, Yonghong Zhou, Cancan Xu, Xueqing Xu   +3 more
wiley   +1 more source

Improved geodetic European very-long-baseline interferometry solution using models of antenna gravitational deformation

Annals of Geophysics, 2010
Very-long-baseline interferometry (VLBI) is used for establishing global geodetic networks where the coordinates attain a 1-mm level of precision. Technique-dependent bias can degrade the VLBI positioning accuracy if it is present and unaccounted for ...
Claudio Abbondanza, Pierguido Sarti, Monia Negusini   +2 more
doaj   +1 more source

Are the hosts of VLBI selected radio-AGN different to those of radio-loud AGN?

, 2016
Recent studies have found that radio-AGN selected by radio-loudness show little difference in terms of their host galaxy properties when compared to non-AGN galaxies of similar stellar mass and redshift.
Herrera-Ruiz, N., Middelberg, E., Norris, R. P., Rees, G. A., Spitler, L. R.   +4 more
core   +1 more source

Holocene Paleoenvironment Changes Near Lake Funazoko‐Ike, East Antarctica, Based on Analyses of Sediments and Microfossils

Island Arc, Volume 34, Issue 1, January/December 2025.
ABSTRACT Lake Funazoko‐Ike was formed by a relative sea level fall due to crustal uplift after the melting of the ice sheet. Today, the lake surface lies approximately 25 m below the present sea level. Evidence of these processes is recorded in sediments deposited from the sill to the lake surface around Lake Funazoko‐Ike during the middle to late ...
Satoshi Sasaki, Koji Seto, Kota Katsuki
wiley   +1 more source

Identification of the Early Fermi LAT Gamma-Ray Bright Objects with Extragalactic VLBI sources

, 2009
A list of 205 gamma-ray strong objects was reported recently as a result of a 3-month integration with the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope.
Abdo, Abdo, Atwood, Bassani, Beasley, Fey, Fomalont, Fomalont, Hartman, Healey, Healey, Helmboldt, Kovalev, Kovalev, Kovalev, Lanyi, Lee, Lister, Lister, Lovell, Lähteenmäki, Ma, Mattox, Mirabal, Mirabal, Ojha, Petrov, Petrov, Petrov, Petrov, Pollack, Sowards-Emmerd, Sowards-Emmerd, Y. Y. Kovalev   +33 more
core   +1 more source

A Satellite Drift Scan Approach for Establishing the Pointing Model of Radio Telescopes

Advances in Astronomy, Volume 2025, Issue 1, 2025.
In the era of large satellite constellations, there are more than 1000 satellites in orbit. While the signals from these satellites may pose a risk of radio frequency interference (RFI) to radio telescopes, they also present a potential advantage by serving as high‐spatial‐density pointing references for radio telescopes.
Ye Yuan, Zhi-Yong Liu, Na Wang, Hao Yan, Arpan Hazra   +4 more
wiley   +1 more source

Key Science Observations of AGNs with KaVA Array

, 2015
KaVA (KVN and VERA Array) is a new combined VLBI array with KVN (Korean VLBI Network) and VERA (VLBI Exploration of Radio Astrometry). First, we briefly review the imaging capabilities of KaVA array which actually achieves more than three times better ...
group, KaVA AGN sub working, Kino, Motoki, Niinuma, Kotaro, Sohn, Bong Won, Zhao, Guang-Yao   +4 more
core   +1 more source

A Global Combination of Geodetic Techniques at the Observation Level: New Perspectives on the Terrestrial Reference Frame

Journal of Geophysical Research: Solid Earth, Volume 129, Issue 12, December 2024.
Abstract We describe the development and assessment of a new terrestrial reference frame (TRF) based on a combination of geodetic techniques at the observation level over the period 2010–2022. Included in the solution are observations from the Global Positioning System (GPS), Satellite Laser Ranging (SLR) and Very Long Baseline Interferometry (VLBI). A
B. Haines, W. Bertiger, S. Desai, M. Ellmer, M. Heflin, D. Kuang, G. Lanyi, C. Naudet, A. Peidou, P. Ries, A. Sibois, X. Wu   +11 more
wiley   +1 more source

Linking Planetary Ephemeris Reference Frames to ICRF via Millisecond Pulsars

Universe
The positions of millisecond pulsars (MSPs) can be determined with sub-milliarcsecond (mas) accuracy using both Very Long Baseline Interferometry (VLBI) and timing, referenced to the International Celestial Reference Frame (ICRF) and planetary ...
Li Guo, Yueqi Song, Zhen Yan, Liang Li, Guangli Wang   +4 more
doaj   +1 more source