Results 71 to 80 of about 111,891 (295)

Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z ∼ 6 Quasars. II. A Sample of 19 Quasars [PDF]

open access: yes, 2005
We study the evolution of the ionization state of the intergalactic medium (IGM) at the end of the reionization epoch using moderate-resolution spectra of a sample of 19 quasars at 5.74 < zem < 6.42 discovered in the Sloan Digital Sky Survey.
Xiaohui Fan   +11 more
semanticscholar   +1 more source

Cosmic Bell Test Using Random Measurement Settings from High-Redshift Quasars. [PDF]

open access: yesPhysical Review Letters, 2018
In this Letter, we present a cosmic Bell experiment with polarization-entangled photons, in which measurement settings were determined based on real-time measurements of the wavelength of photons from high-redshift quasars, whose light was emitted ...
D. Rauch   +19 more
semanticscholar   +1 more source

Anisotropy Analysis of Bamboo and Tooth Using 4‐Angle Polarization Micro‐Spectroscopy

open access: yesNano Select, EarlyView.
Super‐resolution via orientation: spatial distribution of specific molecular vibrations are revealed at 1/20 of the diffraction limit. ABSTRACT To investigate the anisotropic properties of biomaterials, two distinct classes are considered as follows: polymer‐based (cellulose in plants) and crystalline‐based (enamel in teeth), each demonstrating ...
Meguya Ryu   +8 more
wiley   +1 more source

Circum-Galactic Medium in the Halo of Quasars

open access: yesFrontiers in Astronomy and Space Sciences, 2017
The properties of circum-galactic gas in the halo of quasar host galaxies are investigated analyzing Mg II 2800 and C IV 1540 absorption-line systems along the line of sight close to quasars.
Riccardo Ottolina   +6 more
doaj   +1 more source

Optical and radio properties of giant radio quasars: Central black hole characteristics

open access: yes, 2012
We analysed the optical and radio properties of lobe-dominated giant-sized (> 0.72 Mpc) radio quasars and compared the results with those derived for a sample of smaller radio sources to determine whether the large size of some extragalactic radio ...
Jamrozy, M., Kuźmicz, A.
core   +1 more source

Quasar-galaxy associations [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 1995
uuencoded Postscript file (including figures and tables), SUSSEX-AST 94/8 ...
Thomas, P. A.   +2 more
openaire   +4 more sources

Rapidly star-forming galaxies adjacent to quasars at redshifts exceeding 6 [PDF]

open access: yesNature, 2017
The existence of massive (1011 solar masses) elliptical galaxies by redshift z ≈ 4 (refs 1, 2, 3; when the Universe was 1.5 billion years old) necessitates the presence of galaxies with star-formation rates exceeding 100 solar masses per year at z > 6 ...
R. Decarli   +13 more
semanticscholar   +1 more source

Flame Retardant Polyolefins Using Fibers From Leather Waste: Adjusting Extrusion Variables to Balance the Property Profile

open access: yesJournal of Vinyl and Additive Technology, EarlyView.
Adjusting extrusion variables are a key to balance the flame retardancy and mechanical properties of polyolefin/leather waste fiber composites. ABSTRACT The extrusion processing variables represent a key to the optimal use of additives and thus the development of flame‐retardant polymer composites. Adjusting the property profile, for example, finding a
Guadalupe Sanchez‐Olivares   +3 more
wiley   +1 more source

Impact of Radio-mode Feedback on the Covering Fraction of the Circumgalactic Medium of Quasars

open access: yesThe Astrophysical Journal
Utilizing data from the Low-Frequency Array Two-meter Sky Survey and the Sloan Digital Sky Survey, we assemble a sample of 1469 projected quasar pairs with detected radio emissions from foreground quasars, as well as a control sample of 5846 pairs ...
Wen-Qiang Liang   +4 more
doaj   +1 more source

Predicting the Yields of z > 6.5 Quasar Surveys in the Era of Roman and Rubin

open access: yesThe Astrophysical Journal, 2023
About 70 luminous quasars discovered at z > 6.5 are strongly biased toward the bright end, thus not providing a comprehensive view of quasar abundance beyond the cosmic dawn. We present the predicted results of the Roman/Rubin high-redshift quasar survey,
Wei Leong Tee   +5 more
doaj   +1 more source

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