Fifty Years of Quasars: Current Impressions and Future Perspectives

Sulentic, J. W.; Marziani, Paola; D’Onofrio, M.

doi:10.1007/978-3-642-27564-7_9

Cited by 7 publications

(3 citation statements)

References 54 publications

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“…We expect that the synergy between reverberation mapping and systematic inter-comparison of optical and UV emission lines coming from ionic species of low-and high-ionization potential for large samples of individual spectra organized along the main sequence yields contextualized inputs leading to full physical and dynamical models of the broad line emitting region, as a function of black hole mass, Eddington ratio, spin, and environment (Marziani et al, 2018). This issue -conceptually analogous to the definition and interpretation of the stellar Hertzsprung-Russell diagram -has been an unremitting problem of quasar research that has remained basically unsolved since quasar discovery (see Sulentic et al 2012.…”

Section: Accreting Black Hole Physics Close To the Event Horizonmentioning

confidence: 99%

A Multimessenger View of Galaxies and Quasars From Now to Mid-century

D’Onofrio

Marziani

2018

Front. Astron. Space Sci.

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In the next 30 years, a new generation of space and ground-based telescopes will permit to obtain multi-frequency observations of faint sources and, for the first time in human history, to achieve a deep, almost synoptical monitoring of the whole sky. Gravitational wave observatories will detect a Universe of unseen black holes in the merging process over a broad spectrum of mass. Computing facilities will permit new high-resolution simulations with a deeper physical analysis of the main phenomena occurring at different scales.Given these development lines, we first sketch a panorama of the main instrumental developments expected in the next thirty years, dealing not only with electromagnetic radiation, but also from a multi-messenger perspective that includes gravitational waves, neutrinos, and cosmic rays. We then present how the new instrumentation will make it possible to foster advances in our present understanding of galaxies and quasars. We focus on selected scientific themes that are hotly debated today, in some cases advancing conjectures on the solution of major problems that may become solved in the next 30 years.

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Section: Accreting Black Hole Physics Close To the Event Horizonmentioning

confidence: 99%

A Multimessenger View of Galaxies and Quasars From Now to Mid-century

D’Onofrio

Marziani

2018

Front. Astron. Space Sci.

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“…Quasars represent the most luminous stable sources in the Universe (e.g., D'Onofrio et al, 2012D'Onofrio et al, , 2016, and it is disturbing that some basic issues still remain unsolved in spite of decade-long efforts (e.g., Sulentic et al, 2012;Antonucci, 2013, and references therein). The overall most pressing issue is perhaps the inability to connect physical parameters (such as black hole mass; Marziani and Sulentic, 2012;Shen, 2013;Peterson, 2014, for recent reviews) to the observational properties of individual quasars.…”

Section: Introductionmentioning

confidence: 99%

The Phylogeny of Quasars and the Ontogeny of Their Central Black Holes

Fraix-Burnet

Marziani

D’Onofrio

et al. 2017

Front. Astron. Space Sci.

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The connection between multifrequency quasar observational and physical parameters related to accretion processes is still open to debate. In the last 20 year, Eigenvector 1-based approaches developed since the early papers by Boroson and Green (1992) and Sulentic et al. (2000b) have been proven to be a remarkably powerful tool to investigate this issue, and have led to the definition of a quasar "main sequence." In this paper we perform a cladistic analysis on two samples of 215 and 85 low-z quasars (z 0.7) which were studied in several previous works and which offer a satisfactory coverage of the Eigenvector 1-derived main sequence. The data encompass accurate measurements of observational parameters which represent key aspects associated with the structural diversity of quasars. Cladistics is able to group sources radiating at higher Eddington ratios, as well as to separate radio-quiet (RQ) and radio-loud (RL) quasars. The analysis suggests a black hole mass threshold for powerful radio emission and also properly distinguishes core-dominated and lobe-dominated quasars, in accordance with the basic tenet of RL unification schemes. Considering that black hole mass provides a sort of "arrow of time" of nuclear activity, a phylogenetic interpretation becomes possible if cladistic trees are rooted on black hole mass: the ontogeny of black holes is represented by their monotonic increase in mass. More massive radio-quiet Population B sources at low-z become a more evolved counterpart of Population A i.e., wind dominated sources to which the "local" Narrow-Line Seyfert 1s belong.

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“…This formalism also assisted the interpretation of several observational aspects that appear puzzling if, for example, sets of spectra are indiscriminately averaged together. Spectra can be averaged, but only in a well-defined context like the 4DE1 (Sulentic, Marziani & D'Onofrio 2012 ). In addition, it helps to establish a connection between an observational set of accretion parameters such as black hole mass ( M BH ) and Eddington ratio ( λ E = L bol / L Edd ; see e.g.…”

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Optical and near-UV spectroscopic properties of low-redshift jetted quasars in the main sequence context

Mengistue,

Del Olmo,

Marziani

et al. 2023

Monthly Notices of the Royal Astronomical Society

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This paper presents new optical and near-UV spectra of 11 extremely powerful jetted quasars, with radio to optical flux density ratio > 103, that concomitantly cover the low-ionization emission of Mg iiλ2800 and h β as well as the Fe ii blends in the redshift range 0.35 ≲ z ≲ 1. We aim to quantify broad emission line differences between radio-loud (RL) and radio-quiet (RQ) quasars by using the 4D eigenvector 1 parameter space and its Main Sequence (MS) and to check the effect of powerful radio ejection on the low ionization broad emission lines. The h β and Mg iiλ2800 emission lines were measured by using non-linear multicomponent fittings as well as by analysing their full profile. We found that broad emission lines show large redward asymmetry both in h β and Mg iiλ2800. The location of our RL sources in a UV plane looks similar to the optical one, with weak Fe iiUV emission and broad Mg iiλ2800. We supplement the 11 sources with large samples from previous work to gain some general inferences. We found that, compared to RQ, our extreme RL quasars show larger median h β full width at half maximum (FWHM), weaker Fe ii emission, larger MBH, lower Lbol/LEdd, and a restricted bf space occupation in the optical and UV MS planes. The differences are more elusive when the comparison is carried out by restricting the RQ population to the region of the MS occupied by RL sources, albeit an unbiased comparison matching MBH and Lbol/LEdd suggests that the most powerful RL quasars show the highest redward asymmetries in h β.

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Fifty Years of Quasars: Current Impressions and Future Perspectives

Cited by 7 publications

References 54 publications

A Multimessenger View of Galaxies and Quasars From Now to Mid-century

A Multimessenger View of Galaxies and Quasars From Now to Mid-century

The Phylogeny of Quasars and the Ontogeny of Their Central Black Holes

Optical and near-UV spectroscopic properties of low-redshift jetted quasars in the main sequence context

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