Results 71 to 80 of about 83,297 (253)
Journal of Applied Clinical Medical Physics, Volume 27, Issue 1, January 2026.Abstract Background HyperSight CBCT offers rapid image acquisition and enhanced image quality, supporting its integration into online adaptive radiotherapy (OART). However, its performance under respiratory‐induced tumor motion requires further evaluation.
Yi‐Fang Wang +3 more
wiley +1 more source
Dust emission from quasars and quasar host galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 1999 We test emission models of circum-nuclear dust torii around quasars, at low and high redshifts, by using a large collection of photometric data for an unbiased sample of 120 optically-selected objects with millimetric and sub-millimetric fluxes, including new unpublished data.
Andreani, Paola +2 more
openaire +2 more sources
Comment on "Biases in the Quasar Mass-Luminosity Plane" [PDF]
, 2010 Comment on "Biases in the Quasar Mass-Luminosity Plane"Comment: Comment on Biases in the Quasar Mass-Luminosity Plane; 3 ...
Elvis, Martin, Steinhardt, Charles
core
Calibrating the Galaxy Halo - Black Hole Relation Based on the Clustering of Quasars
, 2004 The observed number counts of quasars may be explained either by long-lived activity within rare massive hosts, or by short-lived activity within smaller, more common hosts.
Abraham Loeb +4 more
core +1 more source
Russian VLBI network “Quasar”: Current status and outlook
Geodesy and Geodynamics, 2019 This paper presents the past, present and future status of the Russian VLBI network “Quasar”. This network has been developed for at least 20 years by the Institute of Applied Astronomy of the Russian Academy of Sciences (IAA RAS).
N. Shuygina +17 more
doaj +1 more source
Journal of Applied Clinical Medical Physics, Volume 27, Issue 1, January 2026.Abstract Background Respiratory‐induced tumor motion remains a significant challenge in carbon‐ion radiotherapy (CIRT), potentially compromising dose accuracy and escalating dose in nearby organs. Although belt‐based sensors are commonly used for gating, issues related to setup reproducibility and patient comfort increased the demand for laser‐based ...
Tae‐Ho Kim +9 more
wiley +1 more source
A Physical Model for the Origin of Quasar Lifetimes
, 2005 We propose a model of quasar lifetimes in which observational quasar lifetimes and an intrinsic lifetime of rapid accretion are strongly distinguished by the physics of obscuration by surrounding gas and dust.
Bouchet P. +9 more
core +1 more source
Clustering on very small scales from a large sample of confirmed quasar pairs: Does quasar clustering track from Mpc to kpc scales? [PDF]
, 2017 We present the most precise estimate to date of the clustering of quasars on very small scales, based on a sample of 47 binary quasars with magnitudes of ...
Djorgovski, S. G. +6 more
core +3 more sources
An overview on the quasar redshifts
Revista Técnica de la Facultad de Ingeniería, 2011 An overview of the foundations of modem cosmology a well as the controversies about physical association between high-red shift quasi-stellar objects and low-red shift galaxies are presented. This kind of evidence challenges the current velocity-distance
Williams Pitter +4 more
doaj
Journal of Applied Clinical Medical Physics, Volume 27, Issue 1, January 2026.Abstract Purpose To investigate the effects of targeted modifications to a clinical 4D‐MR pulse sequence on displacement accuracy for abdominal tumor motion tracking, and to compare its performance with established 4D‐MR and 4D‐CT protocols using a motion phantom driven by clinically representative respiratory waveforms.
Morgan Aire +4 more
wiley +1 more source