Results 31 to 40 of about 110,927 (295)
Quantitative Constraints on the Reionization History from the IGM Damping Wing Signature in Two Quasars at z > 7 [PDF]
Astrophysical Journal, 2018 During reionization, neutral hydrogen in the intergalactic medium (IGM) imprints a damping wing absorption feature on the spectrum of high-redshift quasars.
F. Davies +12 more
semanticscholar +1 more source
Tension with the flat ΛCDM model from a high-redshift Hubble diagram of supernovae, quasars, and gamma-ray bursts [PDF]
Astronomy & Astrophysics, 2019 In the current framework, the standard parametrization of our Universe is the so-called Lambda cold dark matter (ΛCDM) model. Recently, a ∼4σ tension with the ΛCDM model was shown to exist via a model-independent parametrization of a Hubble diagram of ...
E. Lusso +6 more
semanticscholar +1 more source
Science, 1986 In the quarter century since the first optical identification of a "radio star" (3C 48), astronomers have come to general agreement that the underlying quasar energy source is accretion onto a massive black hole. There is much less agreement on the detailed physics of the processes by which this energy is converted to the forms observed, but this has ...
Trimble, Virginia, Woltjer, Lodewijk
openaire +4 more sources
An ALMA [C ii] Survey of 27 Quasars at z > 5.94 [PDF]
Astrophysical Journal, 2018 We present a survey of the [C ii] 158 μm line and underlying far-infrared (FIR) dust continuum emission in a sample of 27 quasars using the Atacama Large Millimeter Array (ALMA) at resolution.
R. Decarli +13 more
semanticscholar +1 more source
The Astrophysical Journal, 2023 We present, for the first time, dark matter halo (DMH) mass measurement of quasars at z ∼ 6 based on a clustering analysis of 107 quasars. Spectroscopically identified quasars are homogeneously extracted from the Hyper Suprime-Cam Strategic Survey ...
Junya Arita +12 more
doaj +1 more source
Astronomy & Astrophysics, 2020 Context. In recent years, Lyα nebulae have been routinely detected around high redshift, radio-quiet quasars thanks to the advent of the highly sensitive integral field spectrographs. Constraining the physical properties of the Lyα nebulae is crucial for
A. Travascio +13 more
semanticscholar +1 more source
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). V. Quasar Luminosity Function and Contribution to Cosmic Reionization at z = 6 [PDF]
Astrophysical Journal, 2018 We present new measurements of the quasar luminosity function (LF) at z ∼ 6 over an unprecedentedly wide range of the rest-frame ultraviolet luminosity M1450 from −30 to −22 mag.
Y. Matsuoka +46 more
semanticscholar +1 more source
Obscuration by Gas and Dust in Luminous Quasars [PDF]
, 2014 We explore the connection between absorption by neutral gas and extinction by dust in mid-infrared (IR) selected luminous quasars. We use a sample of 33 quasars at redshifts 0.7 < z < 3 in the 9 deg^2 Bo\"otes multiwavelength survey field that are ...
Brodwin, Mark +3 more
core +3 more sources
Spectral Properties of Quasars from Sloan Digital Sky Survey Data Release 14: The Catalog [PDF]
Astrophysical Journal Supplement Series, 2019 We present measurements of the spectral properties for a total of 526,265 quasars, out of which 63% have a continuum signal-to-noise ratio > 3 pixel−1, selected from the fourteenth data release of the Sloan Digital Sky Survey (SDSS-DR14) quasar catalog ...
S. Rakshit, C. .. Stalin, J. Kotilainen
semanticscholar +1 more source
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). VI. Black Hole Mass Measurements of Six Quasars at 6.1 ≤ z ≤ 6.7 [PDF]
Astrophysical Journal, 2019 We present deep near-infrared spectroscopy of six quasars at 6.1 ≤ z ≤ 6.7 with Very Large Telescope/X-Shooter and Gemini-N/GNIRS. Our objects, originally discovered through a wide-field optical survey with the Hyper Suprime-Cam (HSC) Subaru Strategic ...
M. Onoue +16 more
semanticscholar +1 more source