Results 91 to 100 of about 219,246 (225)
Non-Doppler Redshift and Redshifts of QSOs
, 2013 Quasars have reigned as the most luminous and distant objects in the Universe. These concepts were based on the hypothesis that the redshifts of quasars are obeying the Hubble low. This hypothesis has little serious competition today, but has met some difficulties when using it to determine the distances of quasars.
openaire +2 more sources
An Empirical Consistent Redshift Bias: A Possible Direct Observation of Zwicky’s TL Theory
ParticlesRecent advancements have shown tensions between observations and our current understanding of the Universe. Such observations may include the H0 tension and massive galaxies at high redshift that are older than traditional galaxy formation models have ...
Lior Shamir
doaj +1 more source
GRB optical afterglow and redshift selection effects: The learning curve effect at work
, 2008 We show how the observed gamma ray burst (GRB) optical afterglow (OA) and redshift distributions are changing in time from selection effects. For a subset of {\it Swift} triggered long duration bursts, we show that the mean time taken to acquire ...
Adler +20 more
core +1 more source
Observations Favor the Redshift-evolutionary L X–L UV Relation of Quasars from Copula
The Astrophysical JournalWe compare, with data from quasars, Hubble parameter measurements, and Pantheon+ type Ia supernova, three different relations between X-ray luminosity ( L _X ) and ultraviolet luminosity ( L _UV ) of quasars. These three relations consist of the standard
Bao Wang, Yang Liu, Hongwei Yu, Puxun Wu
doaj +1 more source
Origins And Evolution Of Galactic Type Diversity
International Scholastic Journal of Science, 2016 A study is presented into the origins of galactic type diversity and galaxy evolution through investigating the relationship between representative galaxy color index u-v and redshifts.
Kosuke Kanehisa
doaj
Machine Learning–based Search of High-redshift Quasars
The Astrophysical Journal Supplement SeriesWe present a machine learning search for high-redshift (5.0 < z < 6.5) quasars using the combined photometric data from the Dark Energy Spectroscopic Instrument (DESI) Imaging Legacy Surveys and the Wide-field Infrared Survey Explorer survey.
Guangping Ye, Huanian Zhang, Qingwen Wu
doaj +1 more source
The Astrophysical JournalQuasars could serve as standard candles if the relation between their ultraviolet (UV) and X-ray luminosities can be accurately calibrated. Previously, we developed a model-independent method to calibrate quasar standard candles using the distance ...
Xiaolei Li +2 more
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Evolution of the Cluster Correlation Function
, 2003 We study the evolution of the cluster correlation function and its richness-dependence from z = 0 to z = 3 using large-scale cosmological simulations. A standard flat LCDM model with \Omega_m = 0.3 and, for comparison, a tilted \Omega_m = 1 model, TSCDM,
Bode P. +12 more
core +3 more sources
Probabilistic Forward Modeling of Galaxy Catalogs with Normalizing Flows
The Astronomical JournalEvaluating the accuracy and calibration of the redshift posteriors produced by photometric redshift (photo- z ) estimators is vital for enabling precision cosmology and extragalactic astrophysics with modern wide-field photometric surveys.
John Franklin Crenshaw +7 more
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Detection of gamma-ray burst Amati relation based on Hubble data set and Pantheon+ samples
European Physical Journal C: Particles and FieldsUsing gamma-ray bursts as standard candles for cosmological parameter constraints rely on their empirical luminosity relations and low-redshift calibration.
Yufen Han, Jiaze Gao, Gang Liu, Lixin Xu
doaj +1 more source