Results 41 to 50 of about 18,958 (240)
A Left and Right Truncated Schechter Luminosity Function for Quasars
Galaxies, 2017 The luminosity function for quasars (QSOs) is usually fitted by a Schechter function. The dependence of the number of quasars on the redshift, both in the low and high luminosity regions, requires the inclusion of a lower and upper boundary in the ...
Lorenzo Zaninetti
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The First Bright QSO Survey [PDF]
The Astronomical Journal, 1996 19 pages including 4 tables, 6 figures; AASTEX 4.0. To appear in the August 1996 Astronomical Journal. Complete details of the VLA FIRST survey can be found at http://sundog.stsci.edu/
Robert H. Becker +5 more
openaire +3 more sources
The star formation rates of QSOs
Monthly Notices of the Royal Astronomical Society, 2022 ABSTRACT We examine the far-infrared (FIR) properties of a sample of 5391 optically selected QSOs in the 0.5 < z < 2.65 redshift range down to log [νLν, 2500(erg s−1)] > 44.7, using SPIRE data from Herschel-ATLAS. We split the sample in a grid of 74 luminosity–redshift bins and compute the average optical–IR spectral
M Symeonidis +15 more
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Optical variability of some quasars important to ICRF-Gaia CRF link [PDF]
Serbian Astronomical Journal, 2019 The Gaia optical observations started a few years ago. As a result, the Gaia Celestial Reference Frame (Gaia CRF) should replace the International CRF (ICRF).
Jovanović Miljana D.
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On discrete-time models of network worm propagation generated by quadratic operators
Mathematical Modelling and Analysis, 2023 In this paper we consider the discrete-time dynamical systems generated by network worm propagation models based on the theory of quadratic stochastic operators(QSO).
Fatima Adilova +2 more
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A sample of radio-loud QSOs at redshift ~ 4 [PDF]
, 2003 We obtained spectra of 60 red, starlike objects (E< 18.8) identified with FIRST radio sources, S_{1.4GHz} > 1 mJy. Eight are QSOs with redshift z> 3.6.Combined with our pilot search (Benn et al 2002), our sample of 121 candidates yields a total of 18 z >
Anderson +43 more
core +3 more sources
The Astrophysical Journal Supplement Series, 2023 The Atacama Large Millimeter/submillimeter Array high-frequency long-baseline campaign in 2019 (HF-LBC-2019) was arranged to undertake band 9 (690 GHz) and 10 (850 GHz) observations using the longest 16 km baselines in order to explore calibration ...
Luke T. Maud +8 more
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The Optical Polarization of QSOs [PDF]
Symposium - International Astronomical Union, 1982 Recent optical polarization studies indicate that there are two distinct types of QSOs — “normal” QSOs with P ≲ 1%, and highly polarized QSOs (HPQs) with P > 3%. The HPQs are very similar to BL Lac objects, yet still share some properties of normal QSO's (e.g. strong emission lines).
openaire +2 more sources
Anomalous Redshifts of QSOs [PDF]
Symposium - International Astronomical Union, 1980 The evidence for association of high redshift QSOs with low redshift galaxies is subject to controversies. If it can be convincingly argued that the observed associations are accidental and could occur with reasonably high probabilities (say > 5%) then the cosmological interpretation of the redshifts of QSOs remains unaffected by the data.
P. K. Das, Jayant V. Narlikar
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Radio spectra and polarisation properties of a bright sample of Radio-Loud Broad Absorption Line Quasars [PDF]
, 2012 The origin of broad-absorption-line quasars (BAL QSOs) is still an open issue. Accounting for ~20% of the QSO population, these objects present broad absorption lines in their optical spectra generated from outflows with velocities up to 0.2c.
Adelman-McCarthy +53 more
core +4 more sources