Results 141 to 150 of about 94,086 (264)
The Astrophysical JournalWe previously built a sample of 14,012 extremely variable quasars (EVQs) based on Sloan Digital Sky Survey (SDSS) and Pan-STARRS1 photometric observations.
Wenke Ren +3 more
doaj +1 more source
Discovery of Eight z ~ 6 Quasars in the Sloan Digital Sky Survey Overlap Regions
, 2015 We present the discovery of eight quasars at z~6 identified in the Sloan Digital Sky Survey (SDSS) overlap regions. Individual SDSS imaging runs have some overlap with each other, leading to repeat observations over an area spanning >4000 deg^2 (more ...
Bian, Fuyan +7 more
core +1 more source
A Synoptic, Multiwavelength Analysis of a Large Quasar Sample
, 2005 We present variability and multi-wavelength photometric information for the 933 known quasars in the QUEST Variability Survey. These quasars are grouped into variable and non-variable populations based on measured variability confidence levels. In a time-
A. W. Rengstorf +7 more
core +2 more sources
The Astrophysical JournalThe 21 cm forest is a sensitive probe for the early heating process and small-scale structures during the epoch of reionization (EOR), to be realized with the upcoming Square Kilometre Array (SKA). Its detection relies on the availability of radio-bright
Qi Niu +4 more
doaj +1 more source
On Quasar Masses and Quasar Host Galaxies [PDF]
The Astrophysical Journal, 1998 Accepted for publication in ApJ Letters, 7 pages, aas2pp4 ...
openaire +2 more sources
Clustering of Lyman-alpha Emitters Around Quasars at $z\sim4$
, 2019 The strong observed clustering of $z>3.5$ quasars indicates they are hosted by massive ($M_{\rm{halo}}\gtrsim10^{12}\,h^{-1}\,\rm{M_{\odot}}$) dark matter halos.
Barrientos, L. Felipe +3 more
core +1 more source
A Pilot Study for the CSST Slitless Spectroscopic Quasar Survey Based on Mock Data
The Astrophysical JournalThe wide survey of the Chinese Space Station Telescope (CSST) will observe a large field of 17,500 deg ^2 . The GU, GV, and GI grism observations of CSST will cover the wavelength range from 2550 to 10000 Å at a resolution of R ∼ 200 and a depth of ...
Yuxuan Pang +6 more
doaj +1 more source
The Astrophysical JournalWe report the identification of a quasar overdensity in the BOSSJ0210 field, dubbed the Cosmic Himalayas, consisting of 11 quasars at z = 2.16−2.20, the densest overdensity of quasars (17 σ ) in the ∼10,000 deg ^2 of the Sloan Digital Sky Survey (SDSS ...
Yongming Liang +29 more
doaj +1 more source
Discovery of spectacular quasar-driven superbubbles in red quasars. [PDF]
Sci Adv, 2023 Shen L +9 more
europepmc +1 more source
A search for quasar protoclusters at z greater than 4 [PDF]
In the CDM and many other hierarchical scenarios for the origins of large scale structure, the existence of luminous quasars at very high redshifts (z greater than 3 or 4) is difficult to understand, unless such objects form at the very highest peaks of ...
Djorgovski, S. +2 more
core +1 more source