Results 11 to 20 of about 85,255 (272)
Commissioning and clinical implementation of an MLC tracking system: An evaluation of AAPM TG‐264 guidelines [PDF]
Journal of Applied Clinical Medical Physics, Volume 27, Issue 3, March 2026.Abstract Background Precise radiotherapy relies on accurately targeting tumours while minimising exposure to healthy tissue, yet patient and organ motion complicate treatment delivery. To address intra‐fractional motion, multi‐leaf collimator (MLC) tracking systems have recently been adopted, adapting beam shapes in real‐time.
André Haraldsson +6 more
wiley +2 more sources
Selective Drug‐Free Active Surveillance in Ulcerative Colitis: Biomarker‐Guided, Patient‐Centered Approach [PDF]
JGH Open, Volume 10, Issue 4, April 2026.ABSTRACT Ulcerative colitis (UC) is traditionally managed with long‐term 5‐aminosalicylic acid (5‐ASA) administration. However, in real‐world practice, carefully selected low‐risk patients in sustained deep remission may remain stable without continuous therapy.
Tsutomu Nishida +3 more
wiley +2 more sources
Quasars Probing Quasars. I. Optically Thick Absorbers near Luminous Quasars [PDF]
The Astrophysical Journal, 2006 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 search 149 moderate resolution background quasar spectra, from Gemini, Keck, the MMT, and the SDSS to survey Lyman Limit Systems (LLSs) and Damped Ly-alpha systems (DLAs) in the vicinity of 1.8 < ...
Hennawi, Joseph F. +13 more
openaire +2 more sources
The Astronomical Journal, 2023 We present the first results from a new survey for high-redshift ( z ≳ 5) gravitationally lensed quasars and close quasar pairs. We carry out candidate selection based on the colors and shapes of objects in public imaging surveys, then conduct follow-up ...
Minghao Yue +3 more
doaj +1 more source
The Astrophysical Journal Letters, 2022 We report the discovery of giant (50−100 kpc) [O ii ] emitting nebulae with MUSE in the field of TXS 0206−048, a luminous quasar at z = 1.13. “Down-the-barrel” UV spectra of the quasar show absorption at velocities coincident with those of the extended ...
Sean D. Johnson +12 more
doaj +1 more source
A HUBBLE DIAGRAM FOR QUASARS [PDF]
The Astrophysical Journal, 2015 ApJ ...
Lusso E., RISALITI, GUIDO
openaire +3 more sources
The Astrophysical Journal Supplement Series, 2023 Since their first discovery, quasars have been essential probes of the distant Universe. However, due to our limited knowledge of its nature, predicting the intrinsic quasar continua has bottlenecked their usage.
Zechang Sun, Yuan-Sen Ting, Zheng Cai
doaj +1 more source
Tracing high redshift cosmic web with quasar systems [PDF]
, 2014 We trace the cosmic web at redshifts 1.0
Einasto, Jaan +8 more
core +1 more source
Proceedings of the International Astronomical Union, 2014 AbstractAlthough the extragalactic nature of 3C 48 and other quasi stellar radio sources was discussed as early as 1960 by John Bolton and others, it was rejected largely because of preconceived ideas about what appeared to be unrealistically high radio and optical luminosities.
openaire +2 more sources
Two Close Separation Quasar-Quasar Pairs in the Large Bright Quasar Survey [PDF]
The Astronomical Journal, 1998 Accepted for publication in the Astronomical Journal, Paper, 4 Figures + 1 ...
Hewett, Paul C. +3 more
openaire +2 more sources