Results 241 to 250 of about 79,854 (251)
Quasars: The Observational Perspectives [PDF]
, 2012 The empirical basis of quasar astronomy can be overawing especially in the twenty-first century. A first source of intricacy involves the nomenclature that has evolved to label the multifold phenomenological manifestations now united under the umbrella of active galactic nuclei (AGNs). A further complication involves observations of the many subclasses
Jack W. Sulentic +25 more
openaire +5 more sources
Some of the next articles are maybe not open access.
Related searches:
Related searches:
Applied Optics, 1966
A short historical outline of the discovery and a description of observed properties of quasars introduces questions as to their nature. Some of the principal arguments concerning their reality, distance, intrinsic properties and age lead to the conclusion that, while there is room for other points of view; a strong case can be made for the ...
openaire +2 more sources
A short historical outline of the discovery and a description of observed properties of quasars introduces questions as to their nature. Some of the principal arguments concerning their reality, distance, intrinsic properties and age lead to the conclusion that, while there is room for other points of view; a strong case can be made for the ...
openaire +2 more sources
Bayesian Quasar Selection and the Quasar Luminosity Function
AIP Conference Proceedings, 2008I summarize our work on the construction of deep photometric quasar catalogs using a non‐parametric Bayesian classifier based on kernel density estimation. Using only 5‐band optical data from the Sloan Digital Sky Survey (SDSS), we have identified nearly 1,000,000 photometric quasars candidates over ...
Gordon T. Richards +1 more
openaire +2 more sources
Science, 1964
Rotation in addition to free gravitational motion can produce oscillations in a large spherical mass of gas. The theory may provide an explanation of the variations of brightness in such objects as 3C273.
openaire +3 more sources
Rotation in addition to free gravitational motion can produce oscillations in a large spherical mass of gas. The theory may provide an explanation of the variations of brightness in such objects as 3C273.
openaire +3 more sources
Symposium - International Astronomical Union, 1983
The topic of quasars and superclusters is only a few years old. Although the first pairs of quasars with small angular separations on the sky were found ten years ago (Stockton 1972, Wampler et al. 1973), the pair members had very different redshifts.
openaire +2 more sources
The topic of quasars and superclusters is only a few years old. Although the first pairs of quasars with small angular separations on the sky were found ten years ago (Stockton 1972, Wampler et al. 1973), the pair members had very different redshifts.
openaire +2 more sources
Nature, 2014
An infrared census of accreting supermassive black holes across a wide range of cosmic times indicates that the canonical understanding of how these luminous objects form and evolve may need to be adjusted.
openaire +3 more sources
An infrared census of accreting supermassive black holes across a wide range of cosmic times indicates that the canonical understanding of how these luminous objects form and evolve may need to be adjusted.
openaire +3 more sources