The Question of Quasi-Stellar Objects in Clusters of Galaxies and the Definitions of Quasi-Stellar Objects and Compact Galaxies

1970 ◽  
Vol 162 ◽  
pp. 811 ◽  
Author(s):  
Halton Arp
1972 ◽  
Vol 44 ◽  
pp. 97-103
Author(s):  
W. W. Morgan

Some methods currently in use for the classification of the optical forms of the ‘compact’ galaxies and quasi-stellar objects are reviewed. It is shown that the category ‘Seyfert Galaxy’ is basically a spectroscopic (rather than a form) classification.An optical form-classification is described which is, in principle, identical with published classification criteria for QSO, N-type, and compact objects. The importance of maintaining rigid form-standards is emphasized.


1969 ◽  
Vol 157 ◽  
pp. L77 ◽  
Author(s):  
John N. Bahcall ◽  
Maarten Schmidt ◽  
James E. Gunn

1977 ◽  
Vol 35 ◽  
pp. 167-169
Author(s):  
ROBERT S. DIXON

It has been nearly 70 years since Dreyer completed his famous NGC and IC compendia of all the 13,000 non-stellar objects known in his time. Since then, the number of these objects known has increased by an order of magnitude, but this knowledge is scattered throughout the astronomical literature in such a way that it 1s nearly inaccessible from a practical standpoint to any individual.The present work is an amalgamation of all known catalogs of non-stellar objects, in a uniform, easily readable form. It is Intended not only for astronomers, but also for scientists and engineers in other fields who have need for rapid access to this basic reference data. The types of objects included are galaxies (including both normal and all specialized types such as interacting, peculiar, dwarf, Seyfert, etc.), clusters of galaxies, nebulae of all kinds (planetary, reflection, emission, absorption, etc.), blue objects, groups of stars (open and globular clusters, associations, rings, chains, etc.), quasi-stellar objects, super-novae and others. The Information given for each object includes name, 1950.0 position, angular diameter in arcseconds, magnitude, description, and original reference. A portion of the work is shown in Figure 1. Approximately 185,000 listings appear in the full master 11st.


1971 ◽  
Vol 166 ◽  
pp. L77 ◽  
Author(s):  
John N. Bahcall ◽  
Neta A. Bahcall ◽  
G. R. Burbidge

2019 ◽  
Vol 15 (S356) ◽  
pp. 95-95
Author(s):  
Itziar Aretxaga

AbstractWe present MIR spectroscopy and photometry obtained with CanariCam on the 10.4 m Gran Telescopio CANARIAS for a sample of 20 nearby, MIR bright and X-ray luminous quasi-stellar objects (QSOs). We find that for the majority of QSOs the MIR emission is unresolved at angular scales ∼0.3 arcsec. We derive the properties of the dusti tori that surround the nucleus based on these observations and find significant differences in the parameters compared with a sample of Seyfert 1 and 2 nuclei. We also find evidence for polycyclic aromatic hydrocarbon (PAH) features in the spectra, indicative of star formation, more centrally peaked (on scales of a few hundred pc) than previously believed.


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