Results 121 to 130 of about 18,958 (240)
, 2003 The QSO lifetime t_Q is one of the most fundamental quantities for understanding black hole and QSO evolution, yet it remains uncertain by several orders of magnitude. If t_Q is long, then only a small fraction of galaxies went through a luminous QSO phase. In contrast, a short lifetime would require most galaxies today to have undergone a QSO phase in
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, 2012 We present the results of a search for red QSOs using a selection based on optical imaging from SDSS and near-infrared imaging from UKIDSS. For a sample of 58 candidates 46 (79%) are confirmed to be QSOs. The QSOs are predominantly dust-reddened except a
Fynbo, J. P. U. +7 more
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, 2006 AIMS. To check whether the polar angle distribution of QSOs around nearby spiral galaxies is isotropic or not. METHODS. A statistical analysis of the polar angle distribution of large samples of QSOs from the SDSS survey and Monte Carlo simulations to ...
Abazajian +32 more
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Discrete time model of sexual systems. [PDF]
Heliyon, 2023 Jamilov U, Mukhamedov F, Mukhamedova F.
europepmc +1 more source
High-Redshift QSOs in the GOODS
, 2006 The Great Observatories Origins Deep Survey provides significant constraints on the space density of less luminous QSOs at high redshift, which is particularly important to understand the interplay between the formation of galaxies and super-massive black holes and to measure the QSO contribution to the UV ionizing background. We present the results of
E. Chatzichristou +17 more
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The Astrophysical JournalWe present observations of CO(1–0) and CO(2–1) lines from the Institut de radioastronomie millimétrique 30 m telescope toward 20 nearby, optically luminous type 2 quasars (QSO2s) and observations of the [C ii ] 158 μ m line from the Stratospheric ...
Yuanze Luo +20 more
doaj +1 more source
IEEE Access, 2019 This paper deals with multi-objective optimization design of the airborne electro-optical platform to reduce its mechanical resonance, improve its stability and reduce its mass.
Guoqiang Liu, Weiyi Chen, Huadong Chen
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Physicochemical, Antioxidant and Anticancer Characteristics of Seed Oil from Three Chenopodium quinoa Genotypes. [PDF]
Molecules, 2022 Shen Y +6 more
europepmc +1 more source
The abundance of nitrogen in QSOs
The Astrophysical Journal, 1976 Models of photoionized QSO emission-line regions show that measurements of O iii/N iv/C iv or N iii/C iii can yield the C/N/O ratios to an accuracy of a factor 2 or better. The N iii/C iii intensity ratios observed for the QSO PKS 1756+237 (z=1.72) implies a N/C abundance ratio 5 times larger than the solar value.
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, 2004 Studies of massive black holes (BHs) in nearby galactic centers have revealed a tight correlation between BH mass and galactic velocity dispersion.
Kormendy J. +5 more
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