Results 1 to 10 of about 6,949,336 (206)
CONSTRAINING SUB-PARSEC BINARY SUPERMASSIVE BLACK HOLES IN QUASARS WITH MULTI-EPOCH SPECTROSCOPY. I. THE GENERAL QUASAR POPULATION [PDF]
The Astrophysical Journal, 2013 We perform a systematic search for sub-parsec binary supermassive black holes (BHs) in normal broad-line quasars at z < 0.8, using multi-epoch Sloan Digital Sky Survey (SDSS) spectroscopy of the broad Hβ line.
Yue Shen +3 more
semanticscholar +8 more sources
QUANTIFYING QUASAR VARIABILITY AS PART OF A GENERAL APPROACH TO CLASSIFYING CONTINUOUSLY VARYING SOURCES [PDF]
The Astrophysical Journal, 2009 Robust fast methods to classify variable light curves in large sky surveys are becoming increasingly important. While it is relatively straightforward to identify common periodic stars and particular transient events (supernovae, novae, microlensing), there is no equivalent for non-periodic continuously varying sources (quasars, aperiodic stellar ...
S. Kozłowski +10 more
openalex +4 more sources
Astroinformatics of galaxies and quasars: a new general method for photometric redshifts estimation
, 2012 The catalogs are available as Cone Searches in the Virtual Observatory. Contact olaurino@head.cfa.harvard.edu AbstractWith the availability of the huge amounts of data produced by current and future large multiband photometric surveys, photometric redshifts have become a crucial tool for extragalactic astronomy and cosmology. In this paper we present a
Omar Laurino
openalex +3 more sources
Massive Spheres in General Relativity & Large Gravitational of Quasars [PDF]
, 1973 287-292The effect of a layer of high density matter surrounding a spherical configuration has been studied. It has been shown that the maximum surface red-shift zs can be as large as 4.828.
Gehlot, G. L., Durgapal, M. C.
core
, 2019 We perform a systematic search for sub-parsec binary supermassive black holes (BHs) in normal broad-line quasars at z < 0.8, using multi-epoch Sloan Digital Sky Survey (SDSS) spectroscopy of the broad H beta line. Our working model is that (1) one and
Loeb, Abraham +3 more
core +1 more source
Optimal distribution of VLBI transmitters in the Galileo space segment for frame ties. [PDF]
Earth Planets Space, 2023 Wolf H, Böhm J.
europepmc +1 more source
THE DISCOVERY OF QUASARS AND ITS AFTERMATH
, 2016 : Although the extragalactic nature of quasars was discussed as early as 1960 by John Bolton and others it was rejected largely because of preconceived ideas about what appeared to be an unrealistically-high radio and optical luminosity.
K. I. Kellermann
core
Origin of regularities in the redshift distributions of distant galaxies and quasars [PDF]
, 1990 A model in which inhomogeneities originated during inflation and transformed eventually into density peaks with maximum wavelength equal to the horizon size at the decoupling epoch (z{sub dec} {approx} 10{sup 3}) would give at the present for very large ...
Ozernoy, Leonid M.
core
Clustering and redshift-space distortions in QSO and galaxy surveys [PDF]
, 2006 In this thesis, we exploit the potential of existing QSO and galaxy surveys for investigating the nature of the large scale structure in the Universe. A detailed analysis of clustering and redshift- space distortions allows us to constrain cosmological ...
Cruz da Angela, José Antonio +1 more
core