Results 71 to 80 of about 91,098 (240)
Environments of Nearby Quasars in Sloan Digital Sky Survey [PDF]
, 2009 For the first time spectroscopic galaxy redshift surveys are reaching the scales where galaxies can be studied together with the nearest quasars. This gives an opportunity to study the dependence between the activity of a quasar and its environment in a more extensive way than before. We study the spatial distribution of galaxies and groups of galaxies
arxiv +1 more source
Quasars Lensed by Globular Clusters of Spiral and Elliptical Galaxies [PDF]
Astron.Lett.33:355-367,2007; Pisma Astron.Zh.33:403-416,2007, 2007 Based on the SDSS catalog, we have found new close quasar-galaxy pairs. Quasars projected onto the halos of nearer galaxies are encountered among the multitude of quasars observed at various distances from us. Among them there are quasars that are close to the galaxies not only in angular separation, but also in redshift.
arxiv +1 more source
Medical Physics, Volume 52, Issue 6, Page 4598-4604, June 2025.Abstract Background Magnetic resonance imaging (MRI) offers superior soft tissue contrast and essential imaging capabilities for modern medicine. MRI is increasingly being used in applications that require a high degree of spatial fidelity; however, distortions are a well‐known limitation of the modality. The mid‐field (0.3 T ≤ B0 < 1 T) has advantages
Curtis N. Wiens +2 more
wiley +1 more source
Quasars in the 2MASS Second Incremental Data Release
, 2001 Using the 2MASS Second Incremental Data Release, we have searched for near infrared counterparts to 13214 quasars from the Veron-Cetty & Veron(2000) catalog.
Baker J. +6 more
core +3 more sources
, 1999 I review recent results for quasars and discuss how they are related to activity in galaxies. Topics included are studies of quasar host galaxies with HST; searches for quasars in the Hubble Deep Field; evolution of the quasar luminosity function; news ...
Osmer, Patrick S.
core +2 more sources
The Astrophysical Journal, 2023 The formation of the first supermassive black holes is expected to have occurred in some most pronounced matter and galaxy overdensities in the early universe.
Qiong Li +16 more
doaj +1 more source
Indentation and Puncturing of Pristine and Flawed Soft Membranes
Fatigue &Fracture of Engineering Materials &Structures, Volume 48, Issue 6, Page 2787-2800, June 2025.ABSTRACT This paper investigates the mechanical behavior of soft elastomeric membranes under indentation by a rigid spherical object, with a particular focus on the failure mechanisms leading to puncture. The study examines both pristine membranes and those with pre‐existing flaws, such as cracks, to explore how these imperfections affect the ...
Matteo Montanari +3 more
wiley +1 more source
arXiv, 2011 The main objective of the Chinese LAMOST spectroscopic quasar survey is to discover 0.4 million new quasars from 1 million quasar candidates brighter than the magnitude limit i=20.5 in the next 5 years. This will hopefully provide the largest quasar sample for the further studies of AGN physics and cosmology.
arxiv
The Astrophysical JournalWe present the optical–near-infrared spectral energy distributions (SED) and near-infrared variability properties of 30 low-redshift iron low-ionization Broad Absorption Line quasars (FeLoBALQs) and matched samples of LoBALQs and unabsorbed quasars ...
Karen M. Leighly +5 more
doaj +1 more source
Statistics of Galactic-scale Quasar Pairs at Cosmic Noon
The Astrophysical Journal, 2023 The statistics of galactic-scale quasar pairs can elucidate our understanding of the dynamical evolution of supermassive black hole (SMBH) pairs, the duty cycles of quasar activity in mergers, or even the nature of dark matter, but they have been ...
Yue Shen +10 more
doaj +1 more source