Results 81 to 90 of about 83,297 (253)
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
Probing ~100 AU Intergalactic MgII Absorbing "Cloudlets" with Quasar Microlensing
, 2006 Intergalactic MgII absorbers are known to have structures down to scales ~ 10^{2.5} pc, and there are now indications that they may be fragmented on scales
Kayser R., Subo Dong
core +3 more sources
Spatially Resolved Patchy Lyman-$\alpha$ Emission Within the Central Kiloparsec of a Strongly Lensed Quasar Host Galaxy at z = 2.8 [PDF]
, 2017 We report the detection of extended Lyman-$\alpha$ emission from the host galaxy of SDSS~J2222+2745, a strongly lensed quasar at $z = 2.8$. Spectroscopic follow-up clearly reveals extended Lyman-$\alpha$ in emission between two images of the central ...
Acharyya, Ayan +12 more
core +2 more sources
EIGER. III. JWST/NIRCam Observations of the Ultraluminous High-redshift Quasar J0100+2802
The Astrophysical Journal, 2023 We present the first rest-frame optical spectrum of a high-redshift quasar observed with JWST/NIRCam in Wide Field Slitless mode. The observed quasar, J0100+2802, is the most luminous quasar known at z > 6. We measure the mass of the central supermassive
Anna-Christina Eilers +8 more
doaj +1 more source
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 +5 more
wiley +1 more source
A Southern Photometric Quasar Catalog from the Dark Energy Survey Data Release 2
The Astrophysical Journal Supplement Series, 2022 We present a catalog of 1.4 million photometrically selected quasar candidates in the southern hemisphere over the ∼5000 deg ^2 Dark Energy Survey (DES) wide survey area. We combine optical photometry from the DES second data release (DR2) with available
Qian Yang, Yue Shen
doaj +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
New Astronomy Reviews, 2006 8 pages, 6 figures, review article with C. Impey at the conference on "QSO Host Galaxies: Evolution and Environment", Aug. 29-Sep.
Peng, Chien Y. +7 more
openaire +2 more sources
Quasar Clustering and the Lifetime of Quasars [PDF]
The Astrophysical Journal, 2001 ApJ Accepted (Feb 2001). 30 pages, 8 embedded ps figures, AASTEX5. Added discussion of quasar luminosity evolution. Also available at http://www.ociw.edu/~martini/pubs/
Martini, Paul, Weinberg, David H.
openaire +3 more sources
, 1998 Semi-analytic models of galaxy formation postulate the existence of virialized gaseous halos around galaxies at high redshifts. A small fraction of the light emitted by any high-redshift quasar is therefore expected to scatter off the free electrons in ...
Abraham Loeb +10 more
core +2 more sources