On the Selection of High-z Quasars Using LOFAR Observations
Frontiers in Astronomy and Space Sciences, 2018 We present a method to identify candidate quasars which combines optical/infrared color selection with radio detections from the Low Frequency ARray (LOFAR) at 150 MHz.
Huub Röttgering +3 more
core +2 more sources
Optical and near-UV spectroscopic properties of low-redshift jetted quasars in the main sequence context [PDF]
Monthly notices of the Royal Astronomical Society, 2023 This paper presents new optical and near-UV spectra of 11 extremely powerful jetted quasars, with radio to optical flux density ratio > 103, that concomitantly cover the low-ionization emission of Mg iiλ2800 and h β as well as the Fe ii blends in the ...
S. Terefe +6 more
semanticscholar +1 more source
The 1905 Einstein equation in a general mathematical analysis model of quasars
, 2010 The 1905 wave equation of Albert Einstein is a model that can be used in many areas, such as physics, applied mathematics, statistics, quantum chaos and financial mathematics, etc. I will give a proof from the equation of A. Einstein’s paper “Zur Elektrodynamik bewegter Körper†it will be done by removing the variable time (t) and the constant (c)
Byron E. Bell
openalex +3 more sources
Connection between Emission and Absorption Outflows through the Study of Quasars with Extremely High Velocity Outflows [PDF]
Astrophysical Journal Letters, 2022 A recently discovered class of outflows, extremely high velocity outflows (EHVOs), may be key to understanding feedback processes, as it is likely the most powerful in terms of mass energy. These EHVOs have been observed at redshifts 1.052 < z em < 7.641,
Paola Rodríguez Hidalgo, A. Rankine
semanticscholar +1 more source
Limiting the Abundance of LIGO/Virgo Black Holes with Microlensing Observations of Quasars of Finite Size [PDF]
Astrophysical Journal Letters, 2022 We present a simple but general argument that strongly limits the abundance of primordial black holes (PBHs) (or other unknown population of compact objects) with masses similar to those determined by LIGO/Virgo from BH binary mergers.
A. Esteban-Gutiérrez +5 more
semanticscholar +1 more source
A quasar microlensing light-curve generator for LSST [PDF]
Monthly Notices of the Royal Astronomical Society, 2020 ABSTRACT We present a tool to generate mock quasar microlensing light curves and sample them according to any observing strategy. An updated treatment of the fixed and random velocity components of observer, lens, and source is used, together with a proper alignment with the external shear defining the magnification map caustic ...
Georgios Vernardos +2 more
openaire +2 more sources
A Generative Model for Quasar Spectra
The Astrophysical Journal, 2022 Abstract We build a multi-output generative model for quasar spectra and the properties of their black hole engines, based on a Gaussian process latent-variable model. This model treats every quasar as a vector of latent properties such that the spectrum and all physical properties of the quasar are associated with non-linear functions ...
Anna–Christina Eilers +5 more
openaire +4 more sources
General Physical Properties of Fermi Blazars [PDF]
Astrophysical Journal Supplement Series, 2023 We study the general physical properties of Fermi blazars using the Fermi fourth source catalog data (4FGL-DR2). The quasi-simultaneous multiwavelength data of Fermi blazars are fitted by using the one-zone leptonic model to obtain some physical ...
Yongyun 永云 Chen 陈 +8 more
semanticscholar +1 more source
Multiple Measurements of Quasars Acting as Standard Probes: Exploring the Cosmic Distance Duality Relation at Higher Redshift [PDF]
Astrophysical Journal, 2020 General relativity reproduces main current cosmological observations, assuming the validity of the cosmic distance duality relation (CDDR) at all scales and epochs.
Xiaogang Zheng +5 more
semanticscholar +1 more source
Systematic search for Gravitational Mirages among General Quasar Samples
, 1993 Not ...
O. Moreau +4 more
openalex +4 more sources