Results 101 to 110 of about 111,891 (295)

Phantom‐based assessment of a modified 4D‐MRI protocol for abdominal tumor motion tracking: Effects of sequence parameters and modality comparison

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, David Solis, Reagan Dugan, Olivia Magneson, Krystal Kirby   +4 more
wiley   +1 more source

Black hole masses and enrichment of z ~ 6 SDSS quasars

, 2007
We present sensitive near-infrared spectroscopic observations for a sample of five z ~ 6 quasars. These are amongst the most distant, currently known quasars in the universe. The spectra have been obtained using ISAAC at the VLT and include the CIV, MgII
Aoki K., Chris Carilli, Dominik A. Riechers, Eddington A. S., Fabian Walter, Fan X., Hans‐Walter Rix, Jaron D. Kurk, Laura Pentericci, Linhua Jiang, Maselli A., Michael A. Strauss, Moorwood A., Ryan-Weber E. V., Stefan Wagner, Venemans B. P., Xiaohui Fan   +16 more
core   +1 more source

Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). II. Discovery of 32 quasars and luminous galaxies at 5.7 < z ≤ 6.8 [PDF]

, 2017
We present spectroscopic identification of 32 new quasars and luminous galaxies discovered at 5 ...
Y. Matsuoka, M. Onoue, N. Kashikawa, K. Iwasawa, M. Strauss, T. Nagao, M. Imanishi, Chien-Hsiu Lee, M. Akiyama, N. Asami, J. Bosch, S. Foucaud, H. Furusawa, T. Goto, J. Gunn, Y. Harikane, H. Ikeda, T. Izumi, T. Kawaguchi, S. Kikuta, K. Kohno, Y. Komiyama, R. Lupton, T. Minezaki, S. Miyazaki, T. Morokuma, Hitoshi Murayama, M. Niida, A. Nishizawa, M. Oguri, Y. Ono, M. Ouchi, P. Price, H. Sameshima, A. Schulze, H. Shirakata, J. Silverman, N. Sugiyama, Philip J. Tait, M. Takada, T. Takata, Masayuki Tanaka, Ji-Jia Tang, Y. Toba, Y. Utsumi, Shiang‐Yu Wang   +45 more
semanticscholar   +1 more source

BAL and non-BAL quasars: continuum, emission, and absorption properties establish a common parent sample [PDF]

Monthly notices of the Royal Astronomical Society, 2019
Using a sample of ≃144 000 quasars from the Sloan Digital Sky Survey Data Release 14, we investigate the outflow properties, evident in both absorption and emission, of high-ionization broad absorption line (BAL) and non-BAL quasars with redshifts 1.6 ≲
A. Rankine, P. Hewett, M. Banerji, G. Richards   +3 more
semanticscholar   +1 more source

Margin reduction and optimal prescription isodose model for liver stereotactic radiotherapy with respiratory motion

Journal of Applied Clinical Medical Physics, Volume 27, Issue 1, January 2026.
Abstract Purpose This study aimed to establish a framework for optimizing planning target volume (PTV) margins in liver SBRT using virtual 4DCT (v4DCT), by introducing the concept of the Dosimetric Coverage Amplitude (DCA) to quantify motion tolerance and deriving an Optimal Margin (OM) that balances tumor coverage with normal‐tissue sparing.
Daisuke Kawahara, Hirokazu Masuda, Takuya Wada, Misato Kishi, Tsuyoshi Katsuta, Yuji Murakami   +5 more
wiley   +1 more source

AllBRICQS: The Discovery of Luminous Quasars in the Northern Hemisphere

The Astrophysical Journal Supplement Series
We present the second catalog of bright quasars from the All-sky BRIght, Complete Quasar Survey (AllBRICQS), focusing on spectroscopically observed quasars in the Northern Hemisphere with Galactic latitude ∣ b ∣ > 10°.
Yunyi Choi, Yuming Fu, Myungshin Im, Xue-Bing Wu, Christopher A. Onken, Christian Wolf, Seo-Won Chang, Hyeonho Choi, Mankeun Jeong, Yongjung Kim, Gu Lim, Yuxuan Pang, Taewan Kim, Jubee Sohn, Dohyeong Kim, Ji Hoon Kim, Eunhee Ko, Gregory S. H. Paek, Sungho Jung   +18 more
doaj   +1 more source

A slitless spectroscopic survey for quasars near quasars

, 2008
We present the results of the Quasars near Quasars (QNQ) survey, a CCD-based slitless spectroscopic survey for faint ...
Adelberger, Appenzeller, Baade, Barbieri, Barger, Becker, Bergeron, Bohuski, Bongiovanni, Chand, Ciliegi, Clowes, Clowes, Cowie, Crampton, Crampton, Croom, Crotts, D'Odorico, D'Odorico, Dinshaw, F. Selman, Francis, G. Worseck, Gaskell, Gratton, Hawkins, Hazard, Hazard, Hazard, Heap, Hennawi, Hennawi, Hennawi, Hewett, Hewett, Hewitt, Hook, Horne, Jakobsen, Jakobsen, Jakobsen, Jakobsen, Jauncey, Jiang, Kim, Krumpe, L. Wisotzki, La Franca, Landolt, Liske, Lopez, Maza, Maza, McIntosh, McMahon, Morris, Murphy, Osmer, Osmer, Osmer, Pascual, Pichon, Prescott, Reimers, Reimers, Richards, Richards, Salzer, Schmidt, Schmidt, Schneider, Schneider, Schneider, Sharp, Shaver, Smette, Sramek, Steidel, Storrie-Lombardi, Szokoly, Trump, Tytler, Vanden Berk, Véron, Warren, Williger, Williger, Wisotzki, Wisotzki, Wolf, Wolf, Worseck, Worseck, Wright, Zheng, Zitelli   +96 more
core   +2 more sources

Quasars Probing Quasars. II. The Anisotropic Clustering of Optically Thick Absorbers around Quasars [PDF]

The Astrophysical Journal, 2007
With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar's environment in absorption. We used a sample of 17 Lyman limit systems with column density N_HI > 10^19 cm^-2 selected from 149 projected quasar pair sightlines, to investigate the clustering pattern of optically thick ...
Hennawi, Joseph F., Prochaska, Jason X.
openaire   +2 more sources

Quasar-mode Feedback in Nearby Type 1 Quasars: Ubiquitous Kiloparsec-scale Outflows and Correlations with Black Hole Properties [PDF]

, 2017
The prevalence and properties of kiloparsec-scale outflows in nearby Type 1 quasars have been the subject of little previous attention. This work presents Gemini integral field spectroscopy of 10 Type 1 radio-quiet quasars at .
D. Rupke, K. Gültekin, S. Veilleux
semanticscholar   +1 more source

Logarithmic and Strong Coupling Models in Weyl‐Type f(Q,T)$f(Q,T)$ Gravity

Annalen der Physik, Volume 538, Issue 1, January 2026.
This work explores Weyl‐type f(Q,T) gravity using recent observational datasets — CC, Pantheon+, Union 3.0, and DESI DR2. Through MCMC analysis of logarithmic and strong coupling models, the study reveals a transition from deceleration to acceleration, quintessence‐to‐phantom dynamics, and late‐time consistency with LCDM, offering a geometry‐driven ...
Rahul Bhagat, S. K. Tripathy, B. Mishra
wiley   +1 more source