Results 1 to 10 of about 133 (106)
Properties of Very Broad Line MgII Radio-Loud and Radio-Quiet Quasars
Galaxies, 2021 We perform an analysis of the properties of radio-loud (RL) and radio-quiet (RQ) quasars with MgII broad emission line (i-band magnitude ≤19.1 and z ≤1.9), selected from the parent sample of SDSS DR7 catalogue.
Avinanda Chakraborty +2 more
doaj +3 more sources
Astronomische Nachrichten, Volume 344, Issue 4, May 2023., 2023 Abstract The non‐linear correlation between the UV and X‐ray emission observed in active galactic nuclei remains a puzzling question that challenges accretion models. While the UV emission originates from the cold disk, the X‐ray emission is emitted by a hot corona whose physical characteristics and geometry are still highly debated.
S. Barnier +3 more
wiley +1 more source
Optical and UV properties of a radio‐loud and a radio‐quiet Population A quasar at high redshift
Astronomische Nachrichten, Volume 343, Issue 1-2, January-February 2022., 2022 Abstract Different properties of quasars may be observed and analyzed through the many ranges of the electromagnetic spectrum. Pioneering studies showed that an “H‐R diagram” for quasars was needed to organize these data, and that more than two dimensions were necessary: a four‐dimensional Eigenvector (4DE1) parameter space was proposed. The 4DE1 makes
Alice Deconto‐Machado +4 more
wiley +1 more source
Peaked sources and narrow‐line Seyfert 1s: A love story
Astronomische Nachrichten, Volume 342, Issue 9-10, Page 1066-1070, November-December 2021., 2021 Abstract The first similarities between peaked sources (PS) and narrow‐line Seyfert 1 (NLS1) galaxies were noticed already 20 years ago. Nowadays, it is known that several sources can share both classifications, and that part of the parent population of γ‐ray emitting NLS1s could be hiding among PS.
Marco Berton, Emilia Järvelä
wiley +1 more source
The Dynamics and Energetics of Remnant and Restarting RLAGN
Galaxies, 2023 In this article, I review past, current, and future advances on the study of radio-loud AGN (RLAGN; radio-loud quasars and radio galaxies) lifecycles exclusively in the remnant and restarting phases.
Vijay H. Mahatma
doaj +1 more source
Astronomische Nachrichten, Volume 341, Issue 3, Page 300-313, March 2020., 2020 Abstract We analyze emission line properties and their correlations for 18,043 type 1 active galactic nucleus (AGN) in the range of 0.02 ≤ z ≤ 0.8, based on Sloan Digital Sky Survey Data Release 14 data. We complement the data with photometric measurements from ROSAT, GALEX, 2MASS, and FIRST.
Irham Taufik Andika +2 more
wiley +1 more source
The Nature of the IMBH Candidate CXO J133815.6+043255: High-frequency Radio Emission
The Astrophysical Journal, 2023 The ultraluminous X-ray source CXO J133815.6+043255 is a strong candidate for a bona fide intermediate-mass black hole residing in the outskirts of NGC 5252.
Krista Lynne Smith +2 more
doaj +1 more source
Metal Content in Relativistically Jetted and Radio-Quiet Quasars in the Main Sequence Context
Galaxies, 2023 The optical and UV properties of radio-quiet (RQ) and radio-loud (RL, relativistically “jetted”) active galactic nuclei (AGN) are known to differ markedly; however, it is still unclear what is due to a sample selection and what is associated with ...
Paola Marziani +3 more
doaj +1 more source
The Pan-STARRS1 z > 5.6 Quasar Survey. II. Discovery of 55 Quasars at 5.6 < z < 6.5
The Astrophysical Journal Supplement Series, 2023 The identification of bright quasars at z ≳ 6 enables detailed studies of supermassive black holes, massive galaxies, structure formation, and the state of the intergalactic medium within the first billion years after the Big Bang.
Eduardo Bañados +22 more
doaj +1 more source
Symmetry and the Arrow of Time in Theoretical Black Hole Astrophysics
Journal of Gravity, Volume 2015, Issue 1, 2015., 2015 While the basic laws of physics seem time‐reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time.
David Garofalo, Cosimo Bambi
wiley +1 more source